Search the Community

Showing results for tags 'diet'.

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Group


Title


First Name


Surname


Job Title


Academic degree (if any)


Mobile


Social network profile (if any)


Website (if any)

Found 9 results

  1. When we eat at regular intervals, our body is discouraged from storing calories. This statement is up for debate and there are certain factors we must take into account when considering the above.  In order to answer this question, we must look at our basal metabolic rate or BMR. BMR is the amount of energy released by our body when it is at rest. A high BMR means we can eat more food without getting fat. Exercise also plays a part in increasing our body’s BMR. However, there is no clear answer as to how often we should eat during a day. In a nutshell, eating several small meals a day is tied to the amount of energy our body needs to spend and not the quantity of mealtimes.[1] Mealtimes in the western population are rapidly shifting towards a less structured pattern. With the rise in ready made meals and fast food chains, people have quick and easy access to food. Therefore, they are able to eat food at their own convenience, at any time or place. According to a study conducted on the subject, researchers have discovered that lacking consistency when it comes to eating may have negative effects on insulin.[2][3] An irregular eating pattern was linked to a decrease in what is known as thermic effect of food (TEF). This means that the body burns calories at a slow rate. It also leads to high concentrations of insulin in the blood. TEF triggers a signal in the brain indicating that the body is full and is no longer hungry. It is low in people who do not have fixed meal times, so an increase in their body weight occurs as a result.[4] Free and multiple access VS. restricted access meals Eating meals on irregular basis and lacking consistency is a potentially serious novel environmental risk factor.[2] This risk factor can lead to obesity and metabolic syndrome which includes increased blood pressure, high blood sugar and cholesterol. Stress is also a factor that should be taken into consideration. High levels of stress are capable of changing a person’s eating pattern and encouraging the consumption of tasty, highly palatable foods. In addition, there is rising evidence that irregular eating patterns can have negative effects on a person’s metabolism, especially in the absence of regular exercise. This adds credibility to the theory that highlights the advantages of staying consistent when it comes to eating several meals a day.[1][3] Eating three meals per day, in addition to snacks, is the most common eating pattern in modern societies. However, this is considered abnormal from an evolutionary point of view.[5] Studies conducted on animal models and human subjects indicate that regular fasting which lasts up to sixteen hours can improve health and help combat diseases. It also encourages the body to shield from and repair damage on a cellular level.[6] However the data on intermittent fasting is yet sparse and all the mechanisms are not fully known. It means that to achieve the positive health outcomes fasting should be properly controlled for every individual. Until substantial research is done it is not recommended to include intermittent fasting as a part of weekly eating regime.[7] Mice who were subjected to alternate day fasting diet while keeping the overall food intake unchanged remained the same weight-wise.[6] This intermittent fasting generated positive outcomes that surpassed those of the calorie restriction diet. These included low blood sugar and insulin levels in addition to better resistance of brain neurons to damage and death.[6]  A similar study also showed that mice who were subjected to time restricted feeding (TRF) received the same calories from their high food diet as those who were free to eat whenever they chose to.[8] Time restricted feeding means being fed within a specific window of time. The mice in the time restricted feeding group had protection against obesity and excessive insulin levels in the blood. They were also shielded from fatty liver when fat accumulates in the liver, leading to inflammation and liver failure. The TRF diet is mainly used as a non-pharmacological method to fight obesity and other diseases.[8] Hunger and Satiety When it comes to hunger and satiety, multiple studies have shown that more frequent meals per day may contribute to better appetite control.[9] While another review article agrees with it, the authors also report that eating 3 meals per day is associated with insignificantly lower calories intake when compared to more frequent meals.[10] Low frequency diet could be used for some specific groups of people requiring hypoenergetic (low energy) diet. It was found that eating breakfast and lunch is more effective than eating six smaller portions in low energy diets for type-2 diabetes patients.[11] The question of timing is also very important when it comes to eating. This question has prompted researchers to look into the correlation of eating breakfast and evening meals to the total calories intake. They have shown that satiating morning meals and smaller evening meals reduce the daily calories intake and help people lose weight.[12][13] Physical Exercise is Essential  In the absence of physical activity, eating multiple meals may not lead to better appetite control. It also does not change the body’s composition in a positive manner, especially in non-active people. Adequate protein levels may help athletic people in maintaining their lean body mass if they increase their number of meals. More meals than fewer have a positive effect on different blood markers of health such as LDL cholesterol, total cholesterol as well as insulin. It also helps decrease hunger and improve appetite control.[5] A small number of studies whose participants were athletes showed that increased meal frequency had many benefits. Firstly, it prevents the body from losing lean body mass during a low energy diet. Secondly, it leads to a significant increase in lean body mass and anaerobic power. Thirdly, it helps people get rid of fat.[14][15] Conclusion  Dividing meals into smaller portions leads to better satiety and allows for better caloric control. However, there are no other proven health benefits linked to this eating pattern. It is thought that the total caloric intake, meal time and the regularity pattern of food intake are important rather than the number of meals per day. Still for some groups of people frequent small meals are beneficial, e.g. for sportsmen it helps to increase the lean body mass and power. So this is the quantity of food and regularity pattern that actually matters the most.  [1] Parks, E., & McCrory, M. (2005). When to eat and how often?. Am J Clin Nutr, 81(1), 3-4. Retrieved from http://ajcn.nutrition.org/content/81/1/3.full  [2] Sierra-Johnson, J., Undén, A., Linestrand, M., Rosell, M., Sjogren, P., & Kolak, M. et al. (2008). Eating Meals Irregularly: A Novel Environmental Risk Factor for the Metabolic Syndrome. Obesity, 16(6), 1302-1307. http://dx.doi.org/10.1038/oby.2008.203 [3] Mattson, M., Allison, D., Fontana, L., Harvie, M., Longo, V., & Malaisse, W. et al. (2014). Meal frequency and timing in health and disease. Proceedings Of The National Academy Of Sciences, 111(47), 16647-16653. http://dx.doi.org/10.1073/pnas.1413965111 [4] Farshchi, H., Taylor, M., & Macdonald, I. (2004). Decreased thermic effect of food after an irregular compared with a regular meal pattern in healthy lean women. International Journal Of Obesity, 28(5), 653-660. http://dx.doi.org/10.1038/sj.ijo.0802616 [5] La Bounty, P., Campbell, B., Wilson, J., Galvan, E., Berardi, J., & Kleiner, S. et al. (2011). International Society of Sports Nutrition position stand: meal frequency. Journal Of The International Society Of Sports Nutrition, 8(1), 4. http://dx.doi.org/10.1186/1550-2783-8-4 [6] Anson, R., Guo, Z., de Cabo, R., Iyun, T., Rios, M., & Hagepanos, A. et al. (2003). Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proceedings Of The National Academy Of Sciences, 100(10), 6216-6220. http://dx.doi.org/10.1073/pnas.1035720100 [7] Horne, B., Muhlestein, J., & Anderson, J. (2015). Health effects of intermittent fasting: hormesis or harm? A systematic review. American Journal Of Clinical Nutrition, 102(2), 464-470. http://dx.doi.org/10.3945/ajcn.115.109553 [8] Hatori, M., Vollmers, C., Zarrinpar, A., DiTacchio, L., Bushong, E., & Gill, S. et al. (2012). Time-Restricted Feeding without Reducing Caloric Intake Prevents Metabolic Diseases in Mice Fed a High-Fat Diet. Cell Metabolism, 15(6), 848-860. http://dx.doi.org/10.1016/j.cmet.2012.04.019 [9] Munsters, M., & Saris, W. (2012). Effects of Meal Frequency on Metabolic Profiles and Substrate Partitioning in Lean Healthy Males. Plos ONE, 7(6), e38632. http://dx.doi.org/10.1371/journal.pone.0038632 [10] Bachman, J., & Raynor, H. (2011). Effects of Manipulating Eating Frequency During a Behavioral Weight Loss Intervention: A Pilot Randomized Controlled Trial. Obesity, 20(5), 985-992. http://dx.doi.org/10.1038/oby.2011.360 [11] Kahleova, H., Belinova, L., Malinska, H., Oliyarnyk, O., Trnovska, J., & Skop, V. et al. (2014). Eating two larger meals a day (breakfast and lunch) is more effective than six smaller meals in a reduced-energy regimen for patients with type 2 diabetes: a randomised crossover study. Diabetologia, 57(8), 1552-1560. http://dx.doi.org/10.1007/s00125-014-3253-5 [12] de Castro, J. (2004). The time of day of food intake influences overall intake in humans. J Nutr., 134(1), 104-111. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/14704301 [13] Keim, N., Van Loan, M., Horn, W., Barbieri, T., & Mayclin, P. (1997). Weight Loss is Greater with Consumption of Large Morning Meals and Fat-Free Mass Is Preserved with Large Evening Meals in Women on a Controlled Weight Reduction Regimen. J Nutr., 127(1), 75-82. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/9040548 [14] Iwao, S., Mori, K., & Sato, Y. (2008). Effects of meal frequency on body composition during weight control in boxers. Scandinavian Journal Of Medicine & Science In Sports, 6(5), 265-272. http://dx.doi.org/10.1111/j.1600-0838.1996.tb00469.x [15] Benardot, D., Martin, D., Thompson, W., & Roman, S. (2005). Between-meal Energy Intake Effects On Body Composition, Performance And Total Caloric Consumption In Athletes. Medicine & Science In Sports & Exercise, 37(Supplement), S339. http://dx.doi.org/10.1097/00005768-200505001-01753
  2. It is indisputable that what we eat is critical to our state of health. Nutrients provide the body with the raw materials for our most basic functions. Essential nutrients are nutrients that the body requires for growth, development and functional maintenance. However many diets, particularly the Western diet, unfortunately lack some of these essential nutrients. Additionally, processed food high in fats and sugars that have been chemically changed, often to the point of becoming toxic, is consumed in increasingly large quantities. As many functions of the body are interactive and interdependent, an imbalance of essential nutrients can have far-reaching negative effects. High levels of some substances found in processed or artificially ‘enhanced’ food may have the ability to alter our metabolic state and adversely affect our body’s functions. In obesity, an overweight but in some ways undernourished, state, the long term risk of chronic diseases including type 2 diabetes, heart disease and arthritis is vastly increased.[1] [2] Until recently it was believed that a wide range of diseases, such as type 2 diabetes, obesity, heart disease, stroke and some cancers could be caused by a single gene mutation. More recent findings, however, indicate that these conditions are attributable to a network of biological dysfunction. Furthermore, it is now also known that a lack of essential nutrients, caused by an inadequate supply in the diet, can be an important factor in this biological dysfunction.[3] In order to better understand and treat these diseases, intense research is required to identify how multiple nutrients interact, and how these interactions affect body functions. As the relationship between nutrition, metabolic function and disease becomes more apparent, the view of the virtues of food in simplistic terms of calories or fat will no doubt require revision.[4] Focus must be drawn to food that it is essential to include, rather than just highlighting those to avoid. In the diet of the future, instead of looking at foodstuffs as the ‘enemy’, to be continually reduced or excluded, we will perhaps instead be directed to see the diet as a means to promote good health. By including the right kinds of foods we may even be able to decrease or eliminate the risk of many diseases that are currently epidemic in Western societies. Additionally, with the advent of personalised medicine and advances in genotyping, future diets may even be designed to coincide with an individual’s unique metabolism.[5] There is increasing evidence of the adverse impact on health caused by food that is processed, or has a high sugar and fat content. As we find out more about the true, scientifically-backed ways to maintain a healthy diet, we can shape our health and even our future. Current thinking shows that a balanced and varied diet consisting of freshly prepared food from natural sources, rich in essential nutrients and free from pesticides is the most sensible option to maintain health.   [1] Li, YX. & Zhou, L. (2015) Vitamin D deficiency, obesity and diabetes. Cell Mol Biol (Noisy-le-grand). 61(3). 35-8. [2] Han, TS. & Lean, ME. (2016) A clinical perspective of obesity, metabolic syndrome and cardiovascular disease. JRSM Cardiovasc Dis. doi: 10.1177/2048004016633371. [3] American Heart Association Nutrition Committee et al. (2006) Diet and lifestyle recommendations revision 2006: a scientific statement from the American Heart Association Nutrition Committee. Circulation. 114(1). 82-96. [4] Rozin, P. et al. (1999) Attitudes to Food and the Role of Food in Life in the U.S.A., Japan, Flemish Belgium and France: Possible Implications for the Diet–Health Debate. Appetite. 33(2). 163-80. [5] Chadwick, R. (2004) Nutrigenomics, individualism and public health. Proceed Nutr Soc. 63(1). 161-6.  
  3. Vitamins, dietary minerals and trace elements are essential to the healthy function of the human body. Vitamins are organic compounds that are vital to, but not always produced by, the body and so have to be obtained through the diet. Similarly, dietary minerals (e.g. calcium and phosphorous) and trace elements, of which even smaller amounts are required (e.g. zinc and selenium), are acquired through food. For the majority of people, a balanced, nutritious diet satisfies the body’s vitamin and mineral requirements.[1] There are two types of vitamins; fat soluble and water soluble. Fat soluble vitamins are found mainly in fatty foods and animal products, such as oils, butter, eggs, liver and oily fish. Whilst the body requires a constant supply of these vitamins, the tiny quantities needed coupled with their storage in the liver and fatty tissue for use when required mean that it is not vital to consume them every day. In fact large doses of fat soluble vitamins can be harmful. For example, the risk of lung and stomach cancers is increased in those who consume 20-30mg/day of B-carotene.[2] However many of the side effects seen with excess vitamin intake are not likely to happen as a result of dietary intake, but rather by exceeding the recommended dose with supplementation.[3], [4], [5]  Water soluble vitamins such as vitamin C, folic acid and niacin are found in a wide range of foods including vegetables, fruit, potatoes, grains and dairy food.[6] These water soluble vitamins are less stable than fat soluble vitamins. They are often destroyed by heat or air, meaning that they cannot be stored by the body and excesses are excreted in urine. The consumption of foods containing water soluble vitamins is therefore needed more often, to maintain the body’s supply. As they are excreted in the urine, water soluble vitamins are generally less harmful than fat soluble vitamins, although very high doses may have an adverse effect on the body.[7] For example, large doses vitamin C can cause diarrhoea,[8] while excess folic acid can have effects that range from abdominal cramps and nausea to confusion and increased seizure frequency.[9] Dietary minerals and trace elements have many functions including building strong bones and teeth, regulating the composition of the fluid inside and surrounding cells, and converting food to energy.[10] However high doses taken over a long period can be harmful, as demonstrated by the doubling of hospital admissions for gastrointestinal problems, 17% increase in kidney stones and 20-40% increase in the risk of a heart attack in those taking calcium supplements.[11] Despite the fact that a varied, healthy diet will provide adequate amounts of all essential vitamins, minerals and trace elements for most people, the use of dietary supplementation is increasing. There is no real evidence, that taking synthesised vitamins and mineral supplements has any real benefit to health. Furthermore, in addition to a lack of proven efficacy, the manufacture of dietary supplements is not regulated as stringently as that of medicines. This is because they are not classified as a food or a drug, and as such, they are not technically permitted to make any health claims. More worryingly, no clinical trials are required prior to their production and sale. Many supplements are manufactured by synthetic methods and contain additives such as sweeteners, which may be harmful to health, and they can interact with prescribed medications with serious and even life-threatening results.[12] In conclusion, naturally occurring vitamins and microelements are an important part of our diet. Whilst many synthetic supplements are available that contain high doses of these essential nutrients, it is often the case that our dietary intake is sufficient, except in cases of diseases or conditions that result in a vitamin deficiency. The potential for damaging effects seen with high intake of certain man made vitamins, coupled with the possibility for drug interactions means that you could be doing more harm than good by taking these ‘healthy’ supplements.   [1]  FAO/WHO (2001) Human vitamin and mineral requirements. Retrieved April 2016 from, http://www.fao.org/3/a-y2809e.pdf [2]  Druesne-Pecollo N, et al. (2010) Beta-carotene supplementation and cancer risk: a systematic review and metaanalysis of randomized controlled trials.Int J Cancer. 127(1). 172-84. [3] Schwalfenberg, GK. & Genius, SJ. (2015) Vitamin D, Essential Minerals, and Toxic Elements: Exploring Interactions between Nutrients and Toxicants in Clinical Medicine.ScientificWorldJournal. 318595. [4]  Brown, AC. (2016) An overview of Herb and dietary supplement efficacy, safety and government regulations in the United States with suggested improvements. Part 1 of 5 series. Food Chem Toxicol. [epub ahead of print] doi: 10.1016/j.fct.2016.11.001. [5] Brown, AC. (2016) Liver toxicity related to herbs and dietary supplements: Online table of case reports. Part 3 of 6. Food Chem Toxicol. [epub ahead of print] doi: 10.1016/j.fct.2016.07.001. [6] CSU (2012) Water-soluble vitamins: B-complex and vitamin C. Retrieved November 2016 from, http://extension.colostate.edu/docs/pubs/foodnut/09312.pdf [7]  CSU (2012) Fat-soluble vitamins: A, D, E, and KB-complex and vitamin C. Retrieved November 2016 from, http://extension.colostate.edu/docs/pubs/foodnut/09315.pdf [8] Mulholland, CA, Benford, DJ. (2007) What is known about the safety of multivitamin-multimineral supplements for the generally healthy population? Theoretical basis for harm. Am J Clin Nutr. 85(1). 318S-322S [9] Rogovik, AL, Vohra, S, Goldman, RD. (2010) Safety considerations and potential interactions of vitamins: should vitamins be considered drugs? Ann Pharmacother. 44(2). 311-24. [10] Shenkin, A. (2006) Micronutrients in health and disease. Postgrad Med J. 82(971). 559-567. [11] Reid, IR, Bristow, SM, Bolland, MJ. (2015) Calcium supplements: benefits and risks. J Intern Med. 278(4). 354-68. [12] Williamson, EM. (2003) Drug-interactions between herbal and prescription medicines. Drug Saf. 26(15). 1075-92.  
  4. A crucial part of a healthy lifestyle is generally considered to be the inclusion of plenty (5-7 portions per day) of fruit and vegetables in our diets. However current farming practices include the use of pesticides, antibiotics and hormones to treat crops in order to increase output via higher crop production and faster plant growth. Furthermore, by limiting pest damage, the use of pesticides can also enhance the looks of produce. These chemicals can remain on the surface of fruits and vegetables, even on organic varieties,[1] contaminating them and leading to pesticide ingestion by consumers. Unfortunately, the drugs, hormones, and pesticides currently in use can be hazardous to humans if consumed in a quantity large enough. By definition, pesticides are designed to kill, and the majority are toxic to humans at some level.[2] Organophosphates (OPs) are a group of organic compounds containing phosphates that are frequently used in pesticides and are known to be toxic to humans.[3], [4], [5]  Studies into the effects of OPs have mainly been carried out in subjects that are exposed to OPs through their occupation, for example, farm workers or crop sprayers. These studies have found the symptoms of OP poisoning to include nausea, abdominal cramps, diarrhoea, dizziness anxiety, and confusion.[6] Fortunately, as severe as the symptoms may be, they are frequently reversible.[6] There have not been as many studies in people who have not been occupationally exposed to pesticides, but those undertaken have found that exposure to a low dose over a long period of time may be associated with neurodegenerative conditions such as Parkinson’s disease.[7], [8] Furthermore, prenatal exposure may result in long term irreversible changes in the brain structure of the unborn child, resulting in a lower IQ and a poorer memory.[9], [10], [11]  One of the larger studies, examining a nationally representative sample of children exposed to a chronic low dose of pesticides, found an increased chance of attention deficit hyperactivity disorder (ADHD) in children aged 8-15 years old.[12] Increased quantities of OPs were also found in their urine, indicating systemic exposure.[12] The degree of damage that pesticides such as OPs can inflict is directly proportional to the amount of substance ingested. It is not disputed that pesticide residues are present on fruit and vegetables, which unfortunately means that, in the quest to remain healthy by eating high proportions of fruits and vegetables in their daily diet, many consumers may also potentially be ingesting high levels of toxins. Could it be that the ‘healthier’ the diet based on a higher fruit and vegetable content, the higher the risk of toxicity? Test data obtained in 2014 from the US Department of Agriculture and the Federal Drug Agency found that as little as 1.7% of tomatoes, 2.2% of cherries, 1.7% of strawberries and 2.5% of peaches were pesticide free, meaning that over 97% of these products were contaminated with these chemicals.[13] The average potato had more pesticide residue by weight than any other produce tested,[13] which is of particular concern as many people eat potatoes most days.[14] The UK’s 2014 Pesticides Residues Committee Annual Report stated that, of 3,615 samples tested, 56.2% had no pesticides, 41.9% contained pesticides below the ‘safe’ limit and 1.9% above the limits.[1]  Whilst these tests mean that the vast majority of pesticide residues were well below the maximum residue limit (MRL) and are therefore unlikely to be toxic, some products did exceed the MRL. Nevertheless, the health benefits of eating plenty of fruit and vegetables remain clear and rather than omitting them from the diet whatsoever, it is advisable to wash fruits and vegetables well. Some studies suggest that washing with salt water is an effective way of removing pesticides.[15], [16] Indeed one study using chinese cabbage found that washing with soda-salt water removed as much as 60% of pesticides.[17] An even better approach is to peel them when possible, to remove the potentially harmful wax that is applied during processing.[18]  Furthermore, whilst organic produce generally contains less pesticide residues than non-organic produce, even these fruits and vegetables are not guaranteed pesticide-free.[19] Tests performed in the EU identified pesticide residues in a wide range of organic food products, even finding traces of the highly toxic dichlorodiphenyltrichloroethane (DDT)[20] Organic regulations stipulate that pesticides can be used in organic production, as long as the chemicals are ‘natural’. However one such ‘natural’ pesticide, rotenone, has been linked to the development of Parkinson’s disease in humans,[21] with such a strong effect that it is now used to create animal models of Parkinson’s disease.[22] With the help of more robust regulations governing organic production, organic fruits and vegetables should one day be the exception to the pesticide--contamination rule. However until then, care should also be taken to wash and peel organic produce. [1] National Archives. (2016)  Retrieved September, 2016, from http://webarchive.nationalarchives.gov.uk/20151023160002/http://pesticides.gov.uk/Resources/CRD/PRiF/Documents/Results and Reports/2014/PRIF Annual Report 2014 FINAL.pdf  [2] Damalas, C. et al. (2011) Pesticide Exposure, Safety Issues, and Risk Assessment Indicators. Int J Environ Res Public Health, 8(5), 1402 - 1419. [3] Costa, L. (2006) Current issues in organophosphate toxicology. Clinica Chimica Acta, 366(1-2), 1-13. [4] Kerami-mohajeri, S. et al. (2011) Toxic influence of organophosphate, carbamate, and organochlorine pesticides on cellular metabolism of lipids, proteins, and carbohydrates.Hum and Experiment Toxicology, 30(9), 1119-1140. [5] Kamanyire, R. (2004). Organophosphate toxicity and occupational exposure. Occupational Medicine, 54(2), 69-75. [6] Peter, JV. et al (2014) Clinical features of organophosphate poisoning: A review of different classification systems and approaches. Indian J Crit Care Med, 18(11), 735-45. [7] Slotkin, T. et al. (2011) Developmental exposure to organophosphates triggers transcriptional changes in genes associated with Parkinson's disease in vitro and in vivo. Brain Res Bull, 86(5-6), 340-347. [8] Berry, C. et al. (2010) Paraquat and Parkinson's disease. Cell Death and Different, 17(7), 1115 - 1125. [9] Ruah, V. et al. (2012) Brain anomalies in children exposed prenatally to a common organophosphate pesticide. PNAS, 109(20), 7871-7876. [10] Cecchi, A. et al. (2012) Environmental exposure to organophosphate pesticides: Assessment of endocrine disruption and hepatotoxicity in pregnant women. Ecotoxicol and Environ Safety, 80(1), 280 -287. [11] Columbia University (2016). Prenatal Exposure to Insecticide Chlorpyrifos Linked to Alterations in Brain Structure and Cognition. Retrieved September, 2016, from https://www.mailman.columbia.edu/public-health-now/news/prenatal-exposure-insecticide-chlorpyrifos-linked-alterations-brain-structure  [12] Bouchard, M. et al. (2010) Attention-deficit/hyperactivity disorder and urinary metabolites of organophosphate pesticides. Pediatrics, 125(6), 1270-1277. [13] USDA (2016) Retrieved September, 2016, from https://www.ams.usda.gov/sites/default/files/media/2014%20PDP%20Annual%20Summary.pdf          [14] King, JC. & Slavin, JL. (2013). White potatoes, human health, and dietary guidance. Adv Nutr, 4(3), 393S-401S. [15] Aktar, W. et al. (2009) Risk assessment and decontamination of Quinalphos under different culinary processes in/on cabbage. Environ Monit Assess, 163(1), 369-377. [16] Vemuri, SB. et al. (2014) Methods for removal of pesticide residues in tomatoes. Food Sci Technol, 2(5), 64-68. [17] Zhang, Y-S. et al. (2013) Study on universal cleaning solution in removing blended pesticide residues in Chinese cabbage. J Environ Chem Ecotoxicol, 5(8), 202-207 [18] Ministry of Fisheries, Crops and Livestock (2004) Retrieved October 2016 from, http://pdf.usaid.gov/pdf_docs/Pnacy849.pdf  [19] European Commission (2008) Annex II: pesticides - plant protection products referred to in Article 5(1). Retrieved October 2016 from, https://members.wto.org/crnattachments/2016/TBT/EEC/16_0337_01_e.pdf  [20] The Expert Committee on Pesticide Residues in Food. (2015) Report on the Pesticide Residues Monitoring Programme for Quarter 1 2015. Retrieved October 2016 from, http://webarchive.nationalarchives.gov.uk/20151023155227/http://www.pesticides.gov.uk/Resources/CRD/PRiF/Documents/Results%20and%20Reports/2015/Q1%202015%20FINAL.pdf  [21] Nandipati, S. & Litvan, I. (2016) Environmental exposures and Parkinson’s Disease. Int J Environ Res Public Health, 13(9), doi: 10.3390/ijerph13090881 [epub ahead of print] [22] Johnson, ME. & Bobrovskaya, L. (2015) An update on the rotenone models of Parkinson's disease: their ability to reproduce the features of clinical disease and model gene-environment interactions. Neurotoxicity, 46, 101-16.
  5. In the last decade diets low in carbohydrates and high in protein have become very popular with athletes and those wishing to lose weight.[1] [2] Perhaps the most famous of these high protein, low carbohydrate diets is the Atkins diet.[1] [3]  In normal diets, carbohydrates contained in food are converted into glucose (sugar), which is then transported around the body where it is used as a source of energy. Glucose is particularly important in  fueling the brain, and tight regulation of glucose metabolism is crucial for brain function.[4] If there is very little carbohydrate in the diet, the liver ‘makes up’ for this lack of energy by converting fats from the diet, or stored within the body, into fatty acids and ketone bodies.[5] Ketone bodies pass into the brain and replace glucose as an energy source.[5] Elevated levels of these ketone bodies in the blood is known as ketosis,[6] which has been shown to reduce the frequency of epileptic seizures, and “ketogenic” low carbohydrate diets are therefore used to treat epilepsy in children.[7]  As low carbohydrate diets force the body to burn fats rather than carbohydrates by inducing a ketogenic metabolism, this can lead to rapid weight loss[1] and improvements in cholesterol and lipid levels.[8] This is thought to also be related to the appetite suppressing action of the diet, as the high protein-content maintains feelings of ‘fullness’, reducing spontaneous food intake and decreasing overall energy intake. However ketosis can also have negative side effects, including nausea, fatigue and weakness, headache, irritability, bad or sweet-smelling breath and dehydration.[9] Diets low in carbohydrate have also been shown to impair athletic performance and endurance, despite their popularity in athletes.[10]  The Atkins program is broken down into four phases (detailed on the diet’s website[11]): Induction: Food choices are limited, focusing on protein, fat, and vegetables that are low in carbohydrates and not ‘starchy’. Protein and fat can be consumed as desired, but no more than 20g of carbohydrate can be consumed per day. Ongoing weight loss: Carbohydrate intake is gradually increased, as is food variety. Monitoring of weight and ‘carbohydrate tolerance’ is used to determine a target amount of carbohydrates to be included in the diet moving forwards. Pre-maintenance: To be started when the dieter is approximately 10lb above target weight. The carbohydrate component of the diet is gradually increased, by 10g per week. Maintenance: Once the optimum carbohydrate intake has been determined, the diet is continued indefinitely, Compared with a standard low-calorie, low-fat diet, people on the Atkins diet lose more weight in the short term (6 months) and also show improved cholesterol levels.[1] At 12 months, however,  both diets show comparable results.[1] In addition to rapid weight loss, research also suggests that people on an “Eco-Atkins” diet, which contains foods rich in vegetable fat and protein, will benefit from reduced risk factors for cardiovascular and metabolic diseases, compared to those whose diets are rich in animal fat and protein.[12] [13]  The Atkins diet has been controversial during its 40-year life span, and it is still unclear how the high amounts of animal protein and fat in the Atkins diet affect long-term health. So if you’re considering a low carbohydrate diet, perhaps you should wonder why in four decades, the Atkins diet is yet to reveal clear benefits, and perhaps consider simply reducing calorie intake and increasing your levels of exercise.   [1] Astrup, A, Meinert Larsen, T, Harper, A. (2004) Atkins and other low-carbohydrate diets: hoax or an effective tool for weight loss? Lancet. 364(9437). 897-9. [2] Cook, CM, Haub, MD. (2007). Low-carbohydrate diets and performance. Curr Sports Med Rep. 6(4). 225-9. [3] Rollo, I. (2003) Understanding the implications of adopting the Atkin’s diet. Nurs Times. 99(43). 20-1. [4] Mergenthaler, P, Lindauer, U, Dienel, GA, Meisel, A. (2013) Sugar for the brain: the role of glucose in physiological and pathological brain function. Trends Neurosci. 36(10). 587-97. [5] Manninen, AH. (2004) Metabolic effects of the very-low-carbohydrate diets: misunderstood “villains” of human metabolism. J Int Soc Sports Nutr. 1(2). 7-11. [6] Kesl, SL, Poff, AM, Ward, NP, Fiorelli, TN, Ari, C, van Putten, AJ, Sherwood, JW, Arnold, P, D’Agostino, DP. (2016) Effects of exogenous ketone supplementation on blood ketone, glucose, triglyceride, and lipoprotein levels in Sprague–Dawley rats. Nutr Metab. 13(9). [epub] doi: 10.1186/s12986-016-0069-y [7] Kossoff, EH, McGrogan, JR, Bluml, RM, Pillas, DJ, Rubenstein, JE, Vining, EP. (2006) A modified Atkins diet is effective for the treatment of intractable pediatric epilepsy. Epilepsia. 47(2). 421-4. [8] Westman, EC, Mavropoulos, J, Yancy, WS, Volek, JS. (2003) A review of low-carbohydrate ketogenic diets. Curr Atheroscler Rev. 5(6). 476-83. [9] The Ohio State University (2008) High protein/ Low carbohydrate diets. Retrieved May 2016 from, https://patienteducation.osumc.edu/Documents/high-pro.pdf [10] Pendergast, DR, Leddy, JJ, Venkatraman, JT. (2000) A perspective on fat intake in athletes. J Am Coll Nutr. 19(3). 345-50. [11] The Atkins Diet (2016) The new atkins diet. Retrieved May 2016 from, http://uk.atkins.com/new-atkins/ [12] Jenkins, DJ, Wong, JM, Kendall, CW, Esfahani, A, Ng, VW, Leong, TC, Faulkner, DA, Vidgen, E, Greaves, KA, Paul, G, Singer, W. (2009) The effect of a plant-based low-carbohydrate ("Eco-Atkins") diet on body weight and blood lipid concentrations in hyperlipidemic subjects. Arch Intern Med. 169(11). 1046-54. [13] Jenkins, DJ, Wong, JM, Kendall, CW, Esfahani, A, Ng, VW, Leong, TC, Faulkner, DA, Vidgen, E, Paul, G, Mukherjea, R, Krul, ES,Singer, W. (2014) Effect of a 6-month vegan low-carbohydrate ('Eco-Atkins') diet on cardiovascular risk factors and body weight in hyperlipidaemic adults: a randomised controlled trial. BMJ Open. 4(2). e003505.  
  6. Logic would suggest that consuming fewer calories should result in weight loss, or at the very least, prevent weight gain. However, in the case of artificial sweeteners, which are lower in calories than sugar,  there is a paradox in that it has been shown that they can actually cause weight gain. Therefore, diet drinks are potentially far from the ‘healthier’ calorie-free alternative to regular drinks that they claim to be. As the artificial sweeteners present in diet drinks are now thought to contribute to the development of obesity,[1] they could in fact actually be quite unhealthy. Artificial sweeteners such as sucralose and aspartame have zero calories yet are intensely ‘sweet’ tasting, but the brain is not as easily fooled as the tongue. Artificial sweeteners provide less actual ‘sweetness’ satisfaction, and furthermore reduce the satisfaction obtained when ‘real’ sugar is consumed.[2] This can actually lead to increased carbohydrate cravings, boosting the inclination to overindulge.[2] [3] The first hints at the potential risks of artificial sweeteners arose over two decades ago when studies began revealing that they can stimulate the appetite,[4] with further investigations linking them to increased carbohydrate cravings,[3] the stimulation of fat storage[5] and weight gain.[1] One recent study that followed 474 diet soda drinkers for nearly 10 years, found that they had a staggering 400% greater increase in waist size during the 10 year study period than those who did not drink diet sodas.[6] This increased waist size is not just an aesthetic issue, it is a powerful indicator of the accumulation of visceral fat. This is a dangerous type of fat that gathers around the internal organs, and is strongly linked with type 2 diabetes and heart disease.[7] [8] In fact waist size is now considered a more powerful predictor of cardiovascular risks than body mass index (BMI).[9] However increased body weight is not the only controversial potential side effect of diet drinks. Early studies showed that some artificial sweeteners caused bladder cancer in laboratory animals, [10] although further studies failed to provide clear evidence of an association with cancer in humans, leaving the results inconclusive.[11] Reports also suggest an association between the consumption of aspartame, a widely used artificial sweetener, and neurological and behavioural reactions.[12] Aspartame has been shown to have the potential to induce serious adverse reactions, including seizures.[13]  So if you’re trying to lose weight, so-called ‘diet’ drinks may not be the healthy alternative that they claim to be. They have the potential for major metabolic, cardiovascular and neurological side effects and can actually contribute to weight gain. That being said, sugary drinks are also potentially damaging to health, so care should also be taken with their consumption. Why not opt for safe and simple water, the benefits of which are well known.   [1] Pepino, MY. (2015) Metabolic effects of non-nutritive sweeteners. Physiol Behav. 152(Pt B). 450-5. [2] Rudenga, KJ, Small. DM. (2012) Amygdala response to sucrose consumption is inversely related to artificial sweetener use. Appetite. 58(2). 504-7. [3] Yang, Q. (2010) Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings. Yale J Biol Med. 83(2). 101-8. [4] Rogers, PJ, Blundell, JE. (1989) Separating the actions of sweetness and calories: Effects of saccharin and carbohydrates on hunger and food intake in human subjects. Physiol Behav. 45(6). 1093-9. [5] Maersk, M, Belza, A, Stødkilde-Jørgensen, H, Ringgaard, S, Chabanova, E, Thomsen, H, Pedersen, SB, Astrup, A, Richelsen, B. (2012) Sucrose-sweetened beverages increase fat storage in the liver, muscle, and visceral fatdepot: a 6-mo randomized intervention study. Am J Clin Nutr. 95(2). 283-9. [6] Fowler, RP, Williams, K, Hazuda, HP. (2015) Diet soda intake is associated with long-term increases in waist circumference in a biethnic cohort of older adults: the San Antonio Longitudinal Study of Aging. J Am Geriatr Soc. 63(4). 708-15 [7] Abraham, TM, Pedley, A, Massaro, JM, Hoffmann, U, Fox, CS. (2015) Association between visceral and subcutaneous adipose depots and incident cardiovascular disease risk factors. Circulation. 132(17). 1639-47.  [8] Han, TS, Lean, ME. (2016) A clinical perspective of obesity, metabolic syndrome and cardiovascular disease. JRSM Cardiovasc Dis. [epub ahead of print] doi: 10.1177/2048004016633371. [9] Bastien, M, Poirier, P, Lemieux, I,  Després, JP. (2014) Overview of epidemiology and contribution of obesity to cardiovascular disease. Prog Cardiovasc Dis. 56(4). 369-81. [10] Takayama, S, Sieber, SM, Adamson, RH, Thorgeirsson, UP, Dalgard, DW, Arnold, LL, Cano, M, Eklund, S, Cohen, SM. (1998) Long-term feeding of sodium saccharin to nonhuman primates: implications for urinary tract cancer. J Natl Cancer Inst. 90(1). 19-25. [11] Kessler, II, Clark, P. (1978) Saccharin, cyclamate and human bladder cancer. No evidence of an association. JAMA. 240(4). 349-55.  [12] Lindseth, GN, Coolahan, SE, Petros,TV, Lindseth, PD. (2014) Neurobehavioural effects of aspartame consumption. Res Nurs Health. 37(3). 185-93. [13] Maher, TJ, Wurtman, RJ. (1987) Possible neurologic effects of aspartame, a widely used food additive. Environ Health Perspect. 75. 53-7.
  7. What makes a healthy diet?

    The foundation of a healthy diet is balance, variety and moderation. The maintenance of a healthy body requires the intake of carbohydrate (sugar, starch or fibre), fat, protein, vitamins and minerals. The World Health Organisation states that a healthy adult diet should therefore ideally contain a balance of fruit, vegetables, legumes (e.g. lentils and beans), nuts and whole grains (e.g. unprocessed cereals or brown rice), with a minimum of five portions (400g) of fruit and vegetables to be consumed daily.[1] To achieve the optimum level of nutrition, a healthy diet should consist of:  Approximately one third starchy foods such as bread, rice or pasta (preferably whole grain varieties, as the increased fibre content is beneficial to the intestine)[2], [3]  Some protein rich foods such as meat, fish or lentils Some milk or other dairy products Limited amounts of fat, salt and sugar Fats should make up less than a third of daily caloric intake, and the unsaturated fats found in fish, avocado, nuts, sunflower and olive oils are preferable to the saturated fats found in fatty meats, coconut oil, cream, cheese and lard. This is because unsaturated fats can provide beneficial fatty acids such as omegas 3 and 6, that are known to help decrease cholesterol levels.[4] Indeed studies have shown that a diet containing a maximum of 10% of daily caloric intake from saturated fat significantly decreases the risk of heart disease.[5], [6]  Studies have also shown that coronary heart disease (CHD) risk is reduced by 10-15% for each 5% of energy intake that is exchanged from saturated to polyunsaturated (but not monounsaturated) fats. Exchanging saturated fat with carbohydrates increases CHD risk, by 7% for each 5% exchanged.[7] Trans fats commonly found in processed or ‘fast’ foods such as pizza, pies and margarines should also be avoided, as they can also increase the risk of raised cholesterol, type 2 diabetes and stroke.[8]  Meat is a good source of protein which also contains vitamins and minerals including iron, zinc and B group vitamins, making it one of the main dietary sources of vitamin B12.[9] Opting for lean meat and skinless poultry can help to reduce the fat intake associated with eating meat. However, certain meat-cooking processes, such as BBQing, have recently been shown to be carcinogenic,[10] and some meat products can contain endocrine-disrupting chemicals,[11] so care should be taken when choosing and preparing meat for consumption. Fish is an alternative significant source of protein which also contains numerous vitamins and minerals. Oily fish is also rich in omega-3 fatty acids which, as stated above, are considered beneficial for health via the prevention of heart disease and reduction of cholesterol levels.[4] However, as with meat, many of the high-temperature cooking processes used on fish can lead to the formation of carcinogenic compounds, such as polyaromatic hydrocarbons. Dairy products such as milk, cheese and yoghurt are also good sources of protein and are rich in calcium, essential for healthy bones. There has previously been controversy over the effect of dairy products in the diet, as some can be quite high in fat. However, observational studies have shown that dairy fat does not necessarily contributes to obesity.[12]  Fruit and vegetables are an essential source of dietary vitamins and minerals, and there is increasing evidence that eating at least five portions a day reduces the risks of heart disease, stroke and some cancers. Studies have demonstrated the efficacy of a Mediterranean style diet, which includes lots of fruits and vegetables, in reducing both cancers and cardiovascular disease [13], [14],[15], [16], [17] However it is important to note that not all fruits and vegetables are equal. For example, a fresh piece of fruit is inherently more healthy than its fried equivalent, a glass of sugar-loaded, low fibre fruit juice or a processed alternative. Care should be taken to always wash and peel fruits and vegetables though, as they are commonly contaminated with pesticide residues, even when organic options are chosen, due to the widespread contamination of our environment.[18], [19]  Sugar should ideally contribute less than 10% of daily caloric intake, or ideally less than 5% for additional health benefits.[20] This is about 50g, or 12 teaspoons, for a person consuming the recommended 2000 calories a day. Sugar is routinely added to numerous foods and drinks by manufacturers, cooks and consumers, but it also occurs naturally in honey, syrups and fruit juices and so monitoring intake can prove difficult.[21], [22], [23] Salt intake should also be limited to 5g (one teaspoon) per day, although iodised salt can be beneficial, as it provides the essential mineral iodine. Reduction in overall salt intake helps prevent high blood pressure and reduces the risk of heart disease. In fact it has been shown that reducing sodium intake to <2 g/day can lower systolic blood pressure by 3.47 mmHg, and diastolic blood pressure by 1.81 mmHg.[24], [25] Consuming more calories than are required by the body will ultimately result in weight gain. When monitoring dietary calorie intake, drinks are often forgotten, yet sugary drinks, beer and alcohol all have a high calorific value.[26] Fats and sugars are good sources of energy, but excessive consumption can also result in obesity and the increased risk of type 2 diabetes, some cancers, heart disease and stroke.[27], [28], [29], [30] Dairy products can also have a high caloric value and should be consumed as part of a balanced diet, choosing low fat options when possible. However it is important to remember that children under two years should not be given skimmed milk, as it lacks essential fatty acids and fat soluble vitamins, which are important for development.  Many eating habits are learned in childhood, so it is important that parents and educators explain the importance of a balanced diet and healthy eating choices early in life. By eating a healthy diet ourselves, and by instilling good eating habits in children we may be able to tackle some of the problems facing the modern world today, such as the increased prevalences of obesity and cancer. [1] Lichtenstein, A et al. (2006). Diet and lifestyle recommendations revision 2006: a scientific statement from the American Heart Association Nutrition Committee.American Heart Association Nutrition Committee, 114(1), 82-96.  [2] Schatzkin, A et al. (2008). Prospective Study of Dietary Fiber, Whole Grain Foods,   and Small Intestinal Cancer. Gastroenterology, 135(4), 1163-1167.  [3] Jenkins , D et al. (1987). Starchy foods and fiber: reduced rate of digestion and improved carbohydrate metabolism , Journal of Gastroenterology.Scandinavian Journal of Gastroenterology, 22(129), 132-141.  [4] Covington, M. (2004). Omega 3 Fatty Acids. American Family Physician, 70(1), 133-140.  [5] Perk, J. et al. (2012). European Guidelines on cardiovascular disease prevention in clinical practice . European Heart Journal, 33(13), 1635-1701. [6] Piepole, M. et al. (2016). 2016 European Guidelines on cardiovascular disease prevention in clinical practice. European Heart Journal, 37(1), 2315 - 2381. [7] Go, AS. et al. (2016). Heart disease and stroke statistics - a 2014 update: a report from the American Heart Association. Circulation, 139(3), e28-292 [8] Mozaffarian, D. (2009). Health effects of trans-fatty acids: experimental and observational evidence. European Journal of Clinical Nutrition, 63(2). [9] Williams, P. (2007). Nutritional composition of red meat. Journal of the Dieticians Association of Australia, 64(S4), 113-119. [10] European Commission. (2002) Polycyclic aromatic hydrocarbons - occurrence in foods, dietary exposure and health effects. Retrieved April 2016 from, http://ec.europa.eu/food/fs/sc/scf/out154_en.pdf  [11] Sanchez-Zamorano LM, et al. (2016) The Western dietary pattern is associated with increased serum concentrations of free estradiol in postmenopausal women: implications for breast cancer prevention. Nutr Res, 36(8), 845-54. [12] Kraytz, M. et al. (2013). The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease Kratz M1, Baars T, Guyenet S.European Journal of Nutrition, 52(1), 1-24. [13] Liu, S. et al. (2000). Fruit and vegetable intake and risk of cardiovascular disease: the Women's Health Study. The American Journal of Clinical Nutrition, 72(4), 922-928.   [14] Report of the joint who/fao expert consultation. (2002). Diet, nutrition and the prevention of chronic diseases. WHO Technical Report Series, 916,  [15] Aune, D. et al. (2012). Fruits, vegetables and breast cancer risk: a systematic review and meta-analysis of prospective studies. Breast Cancer Research and Treatment, 134(2), 479-493.  [16] Williams, M. et al. (2005). The role of dietary factors in cancer prevention: beyond fruits and vegetables. Nutrition in Clinical Practice, 20(4), 451-459.   [17] Slavin, J.L. & Lloyd, B. (2012). Health benefits of fruits and vegetables. Advances in Nutrition, 3(4), 506-516.  [18] European Commission (2008) Annex II: pesticides - plant protection products referred to in Article 5(1). Retrieved October 2016 from, http://ec.europa.eu/agriculture/organic/eu-policy/expert-advice/documents/final-reports/final_report_egtop_on_plant_protection_products_en.pdf  [19] The Expert Committee on Pesticide Residues in Food. (2015) Report on the Pesticide Residues Monitoring Programme for Quarter 1 2015. Retrieved October 2016 from, http://webarchive.nationalarchives.gov.uk/20151023155227/http://www.pesticides.gov.uk/Resources/CRD/PRiF/Documents/Results%20and%20Reports/2015/Q1%202015%20FINAL.pdf [20] World health organisation. (2003). Global Strategy on Diet, Physical Activity and Health. WHO Technical Report Series, 916.  [21] World health organisation. (2015). Sugars intake for adults and children. Guideline.  Retrieved October 2016 from, http://apps.who.int/iris/bitstream/10665/149782/1/9789241549028_eng.pdf [22] Malik, V.S et al. (2010). Sugar-sweetened beverages, obesity, type 2 diabetes mellitus, and cardiovascular disease risk. US National Library of Medicine, 121(11),1356-1364.   [23] Meneton, P et al. (2005). Links Between Dietary Salt Intake, Renal Salt Handling, Blood Pressure, and Cardiovascular Diseases. Physiological Reviews, 85(2), 679-715.  [24] World health organisation. (2012). Sodium intake for adults and children. Guideline. Retrieved October 2016 from, http://apps.who.int/iris/bitstream/10665/77985/1/9789241504836_eng.pdf  [25] Steinberger, J & Daniels, S.R. (2003). Obesity, Insulin Resistance, Diabetes, and Cardiovascular Risk in Children. American Heart Association , 107(1), 1448-1453. [26] Vartanian, LR. et al. (2007) Effects of soft drink consumption on nutrition and health: a systematic review and meta-analysis. Am J Public Health. 97(4). 667-75. [27] Azeem, S. et al. (2015). Diet and Colorectal Cancer Risk in Asia - a Systematic Review. Asian Pacific Journal of Cancer Prevention, 16(13), 5389-5396. [28] Ley, S. et al. (2014). Prevention and management of type 2 diabetes: dietary components and nutritional strategies. Lancet, 383(9933), 1999-2007. [29] De souza, R. et al. (2015). Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. BMJ, 351(H3978), . [30] Richelsen, B. (2013). Sugar-sweetened beverages and cardio-metabolic disease risks. Current Opinion in Clinical Nutrition and Metabolic Care, 16(4), 478-484
  8. Good fats vs bad fats

    Fats in our diet are a valuable source of energy (1 g is equivalent to 9 kcal), and they are essential in a healthy balanced diet. While some fats are beneficial, others, if consumed in excessive amounts, have detrimental effects on health. Fats are classified by their chemical structure, falling into several groups including saturated fats, mono-/polyunsaturated fats and trans fats. The fatty acid chains in saturated fats consist of only single bonds, indicating that there are no bonds available for further binding.[1] Foods that contain high levels of saturated fat include whole milk, butter, cheese, lard, palm oil, coconut oil, “fatty” meat and meat products, fried food, and some cakes, biscuits and pastries. All of the above should be eaten in small amounts as saturated fats have a proven association with increased cholesterol levels, which can progress to clogged arteries and increased risk of heart disease and stroke.[2] There have been numerous studies confirming the benefits of reducing saturated fats in our diets. For example, replacing saturated fats with unsaturated fats reduces cholesterol levels, thus decreasing the risks of heart disease and stroke.[2], [3] Both epidemiological and randomised clinical trials have consistently evidenced that replacing saturated fat with unsaturated fat, is beneficial in coronary heart disease.[4]    The fatty acid chains in unsaturated fats contain either one double bond (monounsaturated fat) or more than one double bond (polyunsaturated fat).[1] Foods rich in these types of fats include vegetable oils such as olive, rapeseed or sunflower oils, avocados, nuts and seeds. It has been demonstrated these fats help decrease the risk of heart disease.[5], [6] Omega-3 fatty acids are a group of polyunsaturated fats found mainly in oily fish such as mackerel, salmon or sardines. Omega-3 fatty acids have many health benefits, and are associated with good heart health as they reduce the risk of blood clots and assist in the regulation of heart rhythm.[7], [8] They are also important during pregnancy and breastfeeding, supporting infant development.[7], [8] Trans-fats are the most harmful to our bodies. This group of fats are manufactured by partially hydrogenating vegetable oils, resulting in a firmer, better tasting fat with an increased shelf life. They are found in most processed and ‘fast’ foods, that are already very high in saturated fats.[9] Manufactured trans-fats have been shown to have an even more adverse impact on cholesterol levels than saturated fats, which in turn is associated with diabetes and cardiovascular disease.[10], [11]   Whilst knowing which fats are more healthy than others can certainly help in reducing the risks associated with fat consumption, some fats can actually become more harmful during cooking, depending on the processes involved. Vegetable oil, for example can accumulate by-products known to pose a significant risk of cardiovascular disease when heated repeatedly.[12] Cooking can also change the ratio of healthier unsaturated fatty acids to unhealthy saturated fats and trans fats.[13] Reducing fat in the diet is advisable to prevent obesity and its related complications, such as type 2 diabetes. Even beneficial mono-/polyunsaturated fats should be consumed in moderation, as they still have a high calorific value. In fact studies on mice have shown that a high fat diet induces greater weight gain than a low fat diet, even if their calorific intake is the same.[14]   A reduction of saturated and trans-fats in the diet can be achieved by avoiding processed and ‘fast’ foods as much as possible and choosing food prepared at home from fresh, low fat ingredients. Lean sources of protein, low fat dairy foods, legumes, fresh fruit and vegetables are a healthier choice than foods high in fat, although beneficial oils such as olive, canola and sunflower oil can be used for cooking and salad dressings. [1] Nelson, D & Cox, M. (2008). Lehninger principles of biochemistry. (5 ed.) [2] Jakopsen, M.U. (2009). Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies. The American Journal of Clinical Nutrition. 85(5). 1425-1432 [3] Mozaffarian, D. et al. (2010). Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials. PLos Med. 7(3). e1000252 [4] Siri-tarino, P.W. et al. (2010). Saturated fatty acids and risk of coronary heart disease: modulation by replacement nutrients. Current atherosclerosis reports. 12(6). 384-390 [5] Covas, M.I. (2007). Olive oil and the cardiovascular system. Nutritional Pharmacology. 55(3). 175-186 [6] Gillingham, L.G. et al. (2011). Dietary monounsaturated fatty acids are protective against metabolic syndrome and cardiovascular disease risk factors. Lipids. 46(3). 209-228 [7] Swanson, D. et al. (2012). Omega-3 fatty acids EPA and DHA: health benefits throughout life. Advances in Nutrition. 3(1). 1-7 [8] Calder, P.C. et al. (2009). Omega-3 polyunsaturated fatty acids and human health outcomes. BioFactors. 35(3). 266-272 [9] Stender, S. et al. (2006). A trans world journey. Atherosclerosis Supplements, 7(2), 47-52. [10] Micha, R. et al. (2009). Trans fatty acids: effects on metabolic syndrome, heart disease and diabetes. Nature Reviews: Endocrinology. 5(6). 335-344 [11] Bhardwaj, S. et al. (2011). Overview of trans fatty acids: Biochemistry and health effects. Diabetes & Metabolic Syndrome: Clinical Research & Reviews. 5(3). 161-164 [12] Ng, CY. et al. (2014) Heated vegetable oils and cardiovascular disease risk factors. Vascul Pharmacol. 61(1). 1-9 [13] Bhardwaj, S. et al. (2016) Effect of heating/reheating of fats/oils, as used by Asian Indians, on trans fatty acid formation. Food Chem. 212. 663-70 [14] Petro, A.E. et al. (2004). Fat, carbohydrate, and calories in the development of diabetes and obesity in the C57BL/6J mouse. Metabolism: clinical and experimental. 53(4). 454-457
  9. Gain weight by going 'diet'

    What is healthy diet Sweeteners, used as sugar replacements, are compounds that are so intensely sweet that only a little is needed to replace a larger amount of sugar. They are available in two forms: natural sweeteners of plant origin and synthetic, artificial sweeteners. Natural sweeteners include glycyrrhizin, thaumatins, rabaudioside, stevioside, monellin, perillaldehyde and osladin.[1] Another natural product, miraculin, is not actually sweet, but transforms our perception of sour taste into sweet taste.[1] Artificial, or synthesised, sweeteners include aspartame, saccharin, acesulfame K and sucralose.[1] Among all sweeteners, artificial sweeteners are consider the worst for us, as they are thought to impact on our health, despite artificially sweetened products often being advertised as “diet” alternatives thanks to their reduced calorie content. This ‘diet’ label comes from old studies that showed artificially sweetened products can assist in weight loss and weight maintenance.[2] However, although sweeteners provide intense sweetness with minimal or no calories, studies suggest that they may actually increase appetite.[1] This can actually lead to increased carbohydrate cravings, boosting the inclination to overindulge.[3] [4] Some studies have also showed that artificially sweetened drinks are linked with an increased incidence of Type 2 Diabetes, although no causal link was identified.[5] One study of 3,682 individuals examined the long-term (7-8 year) relationship between ‘diet’ drink consumption and body weight.[6] Even after adjusting for other weight-gain risk factors (such as exercise and diet), results showed that those who regularly consumed ‘diet’ drinks had a 47% higher BMI increase across the follow-up period than those who did not. Another recent study that followed 474 diet soda drinkers for nearly 10 years, found that their waists grew 70% more than the waists of non-diet soda drinkers. In addition, those who drank two or more diet sodas per day had, on average, nearly 4 times the  increase in waist size during the 10 year study period compared to non-diet soda drinkers.[7] These effects are thought to potentially stem from the way that artificial sweeteners and sugar affect the brain. By providing sweetness without any calories, it is thought that consumption of artificial sweeteners can cause us to crave other sweet foods and drinks, which can contribute to excess calorie consumption. This is because artificial sweeteners provide less ‘sweetness satisfaction’, and actually reduce the ‘reward’ obtained when going on to consume actual sugar.[4] This means that, not only does the artificial sweetener not fully satisfy sweetness cravings, it also reduces how rewarding actual sugar is, and thus more is ingested. This is further supported by results from a study at the University of California, San Diego, in which volunteers underwent functional MRI scans as they took small sips of water sweetened with sugar or sucralose. Sugar activated regions of the brain involved in food reward, while sucralose didn’t.[8] In addition to these effects on carbohydrate cravings and weight gain, reports also suggest an association between the consumption of aspartame, a widely used artificial sweetener, and neurological and behavioural reactions.[9] Furthermore, aspartame has also been shown to have the potential to induce serious adverse reactions, including seizures.[10] Thus when trying to be healthy, opting for ‘diet’ options may not be the quick fix it first seems. Not only can artificial sweeteners cause numerous health problems, they can also actively contribute to weight gain, increased BMI and the development of type 2 diabetes. These sweeteners are therefore perhaps not so sweet after all.   [1] Sardesai, VM. & Waldshan, TH. (1991) Natural and synthetic intense sweeteners. J Nutr Biochem. 2(5). 236-44. [2] Bellisle, F. & Drewnowski, A. (2007)  Intense sweeteners, energy intake and the control of body weight. Eur J Clin Nutr. 61(6). 691-700. [3] Rudenga, KJ. & Small. DM. (2012) Amygdala response to sucrose consumption is inversely related to artificial sweetener use. Appetite. 58(2). 504-7. [4] Yang, Q. (2010) Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings. Yale J Biol Med. 83(2). 101-8. [5] Fagherazzi, G. et al. (2013). Consumption of artificially and sugar-sweetened beverages and incident type 2 diabetes in the Etude Epidemiologique aupres des femmes de la Mutuelle Generale de l'Education Nationale-European Prospective Investigation into Cancer and Nutrition cohort. Am J Clin Nutr. 97(3). 517-23. [6] Fowler, SP. et al. (2008) Fueling the obesity epidemic? Artificially sweetened beverage use and long-term weight gain. Obesity (Silver Spring). 16(8). 1894-900. [7] Fowler, RP. et al. (2015) Diet soda intake is associated with long-term increases in waist circumference in a biethnic cohort of older adults: the San Antonio Longitudinal Study of Aging. J Am Geriatr Soc. 63(4). 708-15 [8] Frank, GK. et al. (2008) Sucrose activates human taste pathways differently from artificial sweetener. Neuroimage. 39(4). 1559-69. [9] Lindseth, GN. et al. (2014) Neurobehavioural effects of aspartame consumption. Res Nurs Health. 37(3). 185-93. [10] Maher, TJ. & Wurtman, RJ. (1987) Possible neurologic effects of aspartame, a widely used food additive. Environ Health Perspect. 75. 53-7.