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Carbohydrates

  • Chicago - May 7, 2019 - A new study released by the Center for Nutrition Research at Illinois Institute of Technology suggests that meals that include fresh avocado as a substitute for refined carbohydrates can significantly suppress hunger and increase meal satisfaction in overweight and obese adults.

    As rates of obesity in the United States continue to rise, the findings from Illinois Tech suggest that simple dietary changes can have an important impact on managing hunger and aiding metabolic control.

    The new research, published in the peer-reviewed journal Nutrients, assessed the underlying physiological effects of including whole and half fresh Hass avocados on hunger, fullness, and how satisfied subjects felt over a six-hour period. Researchers evaluated these effects in 31 overweight and obese adults in a randomized three-arm crossover clinical trial. These dietary changes were also shown to limit insulin and blood glucose excursions, further reducing the risk of diabetes and cardiovascular disease by adding healthy fats and fibers into a regular daily diet.

    "For years, fats have been targeted as the main cause of obesity, and now carbohydrates have come under scrutiny for their role in appetite regulation and weight control," said Britt Burton-Freeman, Ph.D., director of the Center for Nutrition Research at Illinois Tech. "There is no 'one size fits all' solution when it comes to optimal meal composition for managing appetite. However, understanding the relationship between food chemistry and its physiological effects in different populations can reveal opportunities for addressing appetite control and reducing rates of obesity, putting us a step closer to personalized dietary recommendations."

    The research found that meals including avocado not only resulted in a significant reduction in hunger and an increase in how satisfied participants felt, but also found that an intestinal hormone called PYY was an important messenger of the physiological response.

    The study and research team was led by Britt Burton-Freeman, Ph.D., of the Center for Nutrition Research, Institute for Food Safety and Health, Illinois Institute of Technology and was supported by the Hass Avocado Board. The Institute for Food Safety and Health is a one-of-a-kind applied food science and nutrition research consortium comprised of Illinois Tech faculty and staff, the U.S. Food and Drug Administration, and the food industry. In collaboration with the FDA, the institute provides stakeholders with the opportunity to develop and exchange knowledge, experience, and expertise in the areas of food safety, food defense, food processing, and nutrition.

    To read the entire study, visit Nutrients at https://www.mdpi.com/2072-6643/11/5/952.

    Jake DiGregorio
    Communications Director
    Illinois Institute of Technology
    IIT Tower, Suite 13C9-1
    10 West 35th Street, Chicago, IL 60616
    Phone: 312.567.3155
    Cell: 508.414.8853
    jdigregorio@iit.edu

  • Carbohydrates are the most abundant biomolecules on our planet and in our food supply. They exhibit some of the largest differences in their metabolism by different members of the animal kingdom. At one extreme, herbivores can almost completely break down dietary plant material with the help of beneficial bacteria that dwell within their gastrointestinal tract; at the other extreme, true carnivores can’t process most dietary carbohydrates. Humans fall somewhere in between; we derive a great deal of nutrition out of some dietary carbohydrates, but are unable to process others.

    In our diets, digestible carbohydrates consist of sugars and starches, while the indigestible carbohydrates are the fibers and resistant starches1. Dietary sugars are predominantly monosaccharides (sugars consisting of a single unit, such as glucose and fructose) or disaccharides (sugars consisting of two monosaccharides linked together, such as sucrose and lactose). Starches are long chains (polymers) of many linked monosaccharide molecules, usually glucose.

    Monosaccharides are the preferred form by which sugars are absorbed from the intestines, therefore, starches and disaccharide sugars (sucrose, lactose) must be broken down by digestive enzymes before assimilation. Starches are fairly easily digested by the action of pancreatic enzymes, while disaccharide sugars are degraded by enzymes that dwell on the surface of the small intestines. The familiar lactose maldigestion (“lactose intolerance”) experienced by many individuals actually results from the lack of one of these intestinal enzymes (lactase, the enzyme that breaks down lactose into glucose and galactose).

    Fibers and resistant starches are carbohydrates as well. Like starches, fiber is composed of polymers of linked monosaccharide sugars. Unlike starches, however, fibers and resistant starches are not used as a source of calories; humans lack the necessary enzymes to break down resistant starches and fibers, therefore, they are not absorbed. Some soluble fiber and resistant starch is broken down by intestinal bacteria, the rest passes through the gastrointestinal tract intact.

    The majority of dietary carbohydrates are obtained from plant sources (fruits, vegetables, grains). In contrast to animal tissues, which are held together by mostly proteins, plants cells are held together by cellulose and lignin, two types of dietary fiber. The edible portions of plants are usually those that contain large amounts of storage carbohydrates, such as the kernels of grains (which store starches) or fruits (which store sugars). Smaller amounts of carbohydrates are found in animal products; carbohydrates constitute only about one percent of the mammalian body2.

    ROLES OF DIETARY CARBOHYDRATES AND FIBER IN NORMAL METABOLISM
    Although they do not have the diversity in human metabolism as do proteins, dietary carbohydrates and fibers still have a number of fates:
    Fuel Source and Fuel Storage.

    As versatile as humans are in obtaining energy from a variety of macronutrients, the preferred energy source in our metabolism is the carbohydrate glucose. Under normal conditions, the brain uses glucose as an energy source almost exclusively, and most other tissues rely heavily on it. To accommodate the body’s need for glucose, most sugars and starches can be converted into glucose as they are absorbed and distributed amongst various tissue following a meal. Additionally, some amino acids from digested protein can also be converted into glucose (in true carnivores like cats, this is where most glucose comes from).

    Unlike other cellular energy sources (amino acids and fatty acids), glucose can be converted into energy in the absence of oxygen (anaerobic glycolysis). This makes glucose a critical source of quick energy during times when oxygen is scarce, such as during intense exercise.

    Glucose can also be stored for later usage, in the form of glycogen (“animal starch”). Glycogen is abundant in the liver, which stores about a day’s worth of glucose in order to provide enough energy to fuel the brain during periods between meals. Glycogen is also used to store glucose for use in muscles, which rely on it for quickly generating energy. If the dietary intake of carbohydrates exceeds what is needed for immediate energy and glycogen reserves, then the excess is converted to fat for long-term storage.

    Precursors to other biomolecules. Carbohydrates are used to make other important biomolecules. These include: glycosaminoglycans (such as chondroitin, keratin, and hyaluronic acid), important constituents of joints and connective tissues; nucleic acids (DNA and RNA are partially constructed from the sugar ribose); as well as other amino acids and fatty acids for making new cellular proteins and cell membranes.

    Stimulation of digestion. Fiber, despite its non-nutritive value, still has evolved important roles in human physiology. The bulk of insoluble fibers helps digested food to move more easily through the intestines and be readily eliminated from the body. Soluble fibers and resistant starches can provide a source of energy for intestinal bacteria, which themselves provide a number of health benefits, including the stimulation of immunity, protection from pathogenic bacteria, and enhanced absorption of minerals from the diet. Prebiotics, a subset of soluble fiber, have gained attention in recent years in their ability to be selectively fermented by gut flora for a diversity of potential health-promoting benefits3.

    SPECIFIC HEALTH BENEFITS OF CARBOHYDRATES AND FIBER
    Many of the health benefits realized by modifying carbohydrate intake involve altering patterns of consumption: reducing intake of sugars, and increasing intake of fiber. For example, recent emphasis on increased intake of whole grains (which contain significantly more fiber, phytonutrients, and protein than do refined cereal flours) has resulted from several studies which suggest that its consumption may reduce the risk of certain cancers, diabetes, and cardiovascular disease4. Fiber intake, in particular, has been the subject of thousands of studies in humans and animals, in part for its ability to successfully reduce the risk of several diseases by different mechanisms:

    Reducing Chronic Low-level Inflammation. In contrast to the conspicuous inflammation that is characteristic of an injury or infection, chronic low-level inflammation can progress unnoticed. This potentially silent affliction has been associated with the progression of several diseases, including cancer, diabetes, cardiovascular, and kidney diseases. In an analysis of 7 studies on the relationship between weight loss and inflammation, increased fiber consumption correlated with significantly greater reductions in C-reactive protein (CRP), one indicator of low-level inflammation5. In these studies, daily fiber intakes ranging from 3.3 to 7.8 g/MJ (equivalent to about 27 to 64 g/day for a standard 2000 kcal diet) reduced CRP from 25–54 percent in a dose-dependent fashion. The Women’s Health Initiative Study also found significant inverse relationships with dietary soluble and insoluble fiber (over 24 g/day) and certain markers of chronic inflammation6.

    Promoting Healthy Blood Pressure. It is not clear how dietary fiber reduces blood pressure, but many studies have observed this trend. Fiber, when taken with a meal, may by reducing the glycemic index of foods and lowering the response of insulin following a meal (insulin may play a role in blood pressure regulation). Soluble fibers may also increase mineral absorption (such as calcium, magnesium, and potassium; all important for healthy blood pressure) by feeding intestinal flora, which lowers intestinal pH and establish a favorable acidic environment for mineral absorption7. Whatever the cause, at least thirty randomized, controlled clinical trials examined the effects of fiber in both hypertensive and normotensive patients. Across all participants, increased fiber intake demonstrated modest average reductions in systolic (1.13–1.15 mm Hg), and diastolic (1.26–1.65 mm Hg) blood pressure89. Amongst hypertensive patients, the average blood pressure reductions were much larger: A significant average reduction in both systolic (-5.95 mm Hg) and diastolic (-4.20 mm Hg) blood pressure was observed over 8 weeks in trials where hypertensive participants increased their daily fiber intake9.

    Promoting Healthy Levels of Blood Lipids. High-fiber diets have been associated with lower prevalence of cardiovascular disease (10). When included as part of a low-saturated fat/low cholesterol diet, dietary fiber can lower low-density lipoprotein cholesterol (LDL-C) by 5–10 percent in persons with high cholesterol, and may reduce LDL-C in healthy individuals as well10. Dozens of controlled clinical trials have shown the cholesterol-lowering potential of dietary fibers including soluble oat fiber, psyllium, pectin, guar gum, b-glucans from barley, and chitosan3,12,13.

    Soluble fibers lower cholesterol by several potential mechanisms (3). They may directly bind cholesterol in the gut, preventing its absorption. The high viscosity of soluble fiber and its ability to slow intestinal motility may help to limit cholesterol and fat uptake as well. Fiber can also increase satiety, which can limit overall energy intake14,15. Lowering Uric Acid. Elevated blood uric acid (hyperuricemia) is a risk factor for kidney disease, cardiovascular diseases, and diabetes; it is also a primary cause for gout16. Fiber intake may lower blood uric acid levels. A significant inverse relationship between fiber intake and hyperuricemia risk was established by analyzing dietary fiber intake data from over 9000 otherwise healthy adults participating in the National Health and Nutrition Examination Survey (NHANES) from 1999–2004. Based on these data, participants with high fiber diets (over about 19 grams fiber/day for the average 2000 kcal diet) had a 55 percent reduction in hyperuricemia risk compared to those on lower fiber diets (<9.2 g fiber/day)17. While these mechanisms for this reduction is unknown, dietary fiber may reduce the absorption of purines from the diet, one of the inciting factors for hyperuricemia.

    HOW MUCH CARBOHYDRATES AND FIBER SHOULD I BE GETTING?
    The amount and composition of carbohydrates in the “ideal” diet is amongst the most heavily debated topics in nutrition. There are scientifically-substantiated merits to both the “low-carb” and “low-fat, high-carb” diets in terms of reducing disease risk and maintaining a healthy body mass index (these will be discussed in greater detail in a future article). The common ground between the two schools of thought is that the average Western diet probably contains too little fiber, and too much refined grains and added sugar. A low-fiber/high-sugar diet, when coupled with excessive caloric intake, has been associated with significant increases in the risk for a number of ailments, including obesity, insulin resistance/type II diabetes, and cardiovascular disease.

    As mentioned previously, the benefits of dietary fiber are numerous. The average daily fiber intake in the American diet, based on data from 2007–2008 NHANEs survey, is about half of the 28 grams/day recommendation by the Institute of Medicine (IOM). Significant numbers of people consume even less than the national average. The highest intakes of dietary fiber are associated with the lowest disease risks; for several observational studies, the greatest risk reductions required intakes exceeding the IOM recommendations.

    In contrast, the American diet contains no shortage of refined grains or sugars. The U.S. Department of Agriculture estimates average grain consumption at about 33 percent more than 6 oz./day recommended in its Dietary Guidelines for Americans. Most of this grain is refined; the same group estimates Americans consume only one-third of the recommended 3 oz./day of whole grains18,19.

    Analysis of data from the last NHANEs survey (2007–2008) determined that Americans consume an average of 120 grams/day of total sugars (about 30 teaspoons), most of which are added sugars. This amounts to approximately 480 kilocalories of energy per day. Most of these sugars come from sweetened carbonated beverages (~37 percent); other top sources include desserts and fruit drinks (fruitades and fruit punches). While arguments can be made that it is the added fructose or corn syrup are particularly dangerous to health (there is evidence that supports and refutes this hypothesis), or that sugar is additive and contributes to overeating (animal models may support this claim), added sugar clearly contributes a significant amount of calories to the average diet, and in many cases displaces essential nutrients20,21.

    To read the series on Macronutrients:

    References:

    1. Fardet A. New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre? Nutr Res Rev 2010 Jun.;23(1):65–134.
    2. Engelking L. Textbook of Veterinary Physiological Chemistry. Updated 2nd ed. Burlington, MA: Academic Press; 2011.
    3. Brown L, Rosner B, Willett WW, Sacks FM. Cholesterol-lowering effects of dietary fiber: a meta-analysis. Am J Clin Nutr 1999 Jan.;69(1):30–42.
    4. Higgins JA. Whole grains, legumes, and the subsequent meal effect: implications for blood glucose control and the role of fermentation. J Nutr Metab 2012;2012:829238.
    5. North CJ, Venter CS, Jerling JC. The effects of dietary fibre on C-reactive protein, an inflammation marker predicting cardiovascular disease. Eur J Clin Nutr 2009 Aug.;63(8):921–33.
    6. Ma Y, Hébert J, Li W, Bertone-Johnson E. Association between dietary fiber and markers of systemic inflammation in the Women’s Health Initiative Observational Study. Nutrition 2008;
    7. Greger J. Nondigestible carbohydrates and mineral bioavailability. J Nutr 1999.
    8. Streppel MT, Arends LR, van t Veer P, Grobbee DE, Geleijnse JM. Dietary fiber and blood pressure: a meta-analysis of randomized placebo-controlled trials. Arch Intern Med 2005 Jan.;165(2):150–6.
    9. Whelton SP, Hyre AD, Pedersen B, Yi Y, Whelton PK, He J. Effect of dietary fiber intake on blood pressure: a meta-analysis of randomized, controlled clinical trials. J. Hypertens 2005 Mar.;23(3):475–81.
    10. Badimon L, Vilahur G, Padro T. Nutraceuticals and atherosclerosis: human trials. Cardiovasc Ther 2010 Aug.;28(4):202–15.
    11. Anderson J, Randles K. Carbohydrate and fiber recommendations for individuals with diabetes: a quantitative assessment and meta-analysis of the evidence. J Am Coll Nutr 2004.
    12. AbuMweis SS, Jew S, Ames NP. -glucan from barley and its lipid-lowering capacity: a meta-analysis of randomized, controlled trials. Eur J Clin Nutr 2010 Dec.;64(12):1472–80.
    13. Baker WL, Tercius A, Anglade M, White CM, Coleman CI. A meta-analysis evaluating the impact of chitosan on serum lipids in hypercholesterolemic patients. Ann Nutr Metab 2009;55(4):368–74.
    14. Brighenti F, Casiraghi M, Canzi E. Effect of consumption of a ready-to-eat breakfast cereal containing inulin on the intestinal milieu and blood lipids in healthy male volunteers. Eur J Clin Nutr 1999; Pages 726–33.
    15. Li S, Guerin-Deremaux L, Pochat M, Wils D, Reifer C, Miller LE. NUTRIOSE dietary fiber supplementation improves insulin resistance and determinants of metabolic syndrome in overweight men: a double-blind, randomized, placebo-controlled study. Appl Physiol Nutr Metab 2010 Dec.;35(6):773–82.
    16. Zhu Y, Pandya BJ, Choi HK. Prevalence of gout and hyperuricemia in the US general population: The National Health and Nutrition Examination Survey 2007–2008. Arthritis Rheum 2011 Oct.;63(10):3136–41.
    17. Sun SZ, Flickinger BD, Williamson-Hughes PS, Empie MW. Lack of association between dietary fructose and hyperuricemia risk in adults. Nutr Metab 2010;7(1):16.
    18. Grotto D, Zied E. The Standard American Diet and its relationship to the health status of Americans. Nutr Clin Pract 2010 Dec.;25(6):603–12.
    19. U. S. Department of Agricuture USDOHAHS. Dietary Guidelines for Americans 2010. 2011 Jan.;:1–112.
    20. Avena NM, Rada P, Hoebel BG. Sugar and fat bingeing have notable differences in addictive-like behavior. Journal of Nutrition 2009 Mar.;139(3):623–8.
    21. Berner LA, Avena NM, Hoebel BG. Bingeing, self-restriction, and increased body weight in rats with limited access to a sweet-fat diet. Obesity (Silver Spring) 2008 Sep.;16(9):1998–2002.

  • It is New Year's resolution time and one of the perennial resolutions for many Americans is, "this year I am going to lose weight and keep it off."

    Literally two thirds of Americans are overweight or worse, so there are a lot of such resolutions being made. Like gym memberships, however, there are far more resolutions initially undertaken than followed through. Nevertheless, this time around things can be different. One key is that the weight loss strategy adopted should also be one that can be continued as a normal everyday diet pattern. There is no reason that this should not work as long as realistic goals are adopted. Life, as the observation goes, is a marathon, not a sprint. Moderate, yet well thought-out changes in the diet regarding the ratios of protein, carbohydrate and fat can yield durable results over a span of three to six months. Similarly, care in terms of the timing of food intake, consumption of fiber and phytonutrients, and so can yield big rewards.

    High Protein Beats High Carbohydrate During Weight Loss

    Let's start with the initial weight loss goal. Ads for diet products and programs often promise "ten pounds in ten days," but such promises, even were they true, are never lasting. The body resists extreme changes and, in the end, the body always wins. A better approach is to coax the body in the desired direction so that it becomes more metabolically flexible and thus can burn fat for energy rather than storing it. This means overcoming roadblocks such as poor blood sugar control dieting-induced loss of lean tissue. The protein-to-carbohydrate make-up of meals is important here. Indeed, this ratio and not the amount of fat in the diet is determining.

    Realistically, reducing energy intake by approximately 500 calories per day is sufficient for many dieters initially to experience weight loss of 1 – 2 pounds per week. The catch is that weight loss based only on restricting calories has a poor record for improving impaired glucose tolerance and typically leads to a loss of the more actively calorie-metabolizing lean body tissues. A study with obese subjects published in the journal BMJ Open Diabetes Res Care demonstrates that this need not be the outcome of dieting.1 One hundred percent of obese adults using a high protein (HP) moderately calorically-restricted diet, but not those on a similarly restricted high carbohydrate (HC) diet achieved a return to normal glucose tolerance in addition to benefits in their markers for cardiovascular and inflammatory health. On the HP diet there was an increase in the percentage of lean body mass and a decrease in the percentage of fat body mass with weight loss whereas the HC diet led to a decrease in the percentage of lean body mass along with a decrease in the percentage of fat body mass. The change in glucose tolerance/blood sugar levels and the improvement in the percent lean body mass demonstrated with higher protein intake and restricted carbohydrate intake are highly desirable outcomes. The key was substituting protein for carbohydrate calories.

    For this study, researchers randomized 24 women and men with elevated fasting glucose levels in the pre-diabetic range to either a HP diet (30 percent protein, 30 percent fat, 40 percent carbohydrate; n=12) or a HC diet (15 percent protein, 30 percent fat, 55 percent carbohydrate; n=12) for a study lasting six months. All meals were provided to these subjects for the six months. At the start of the study and at its conclusion, tests were performed to determine oral glucose tolerance and serum insulin levels as well as a variety of other parameters indicative of metabolism and inflammation. X-ray scans were conducted to determine body composition in terms of the percentage of lean and fat tissue.

    The differing diets led to dramatically different results. According to the authors of the paper, on the HP diet 100 percent of the subjects exhibited remission of their pre-diabetes to normal glucose tolerance whereas only 33.3 percent of subjects on the HC diet exhibited this remission. Moreover, the high protein arm subjects exhibited significant improvement in (1) insulin sensitivity (p=0.001), (2) cardiovascular risk factors (p=0.04), (3) inflammatory cytokines (p=0.001), (4) oxidative stress (p=0.001), and (5) increased percent lean body mass (p=0.001) compared with the HC diet.

    In terms of the findings likely to be of particular interest to most dieters, it should be pointed out again there was an increase in the percentage of lean body mass and decrease in the percentage of fat body mass with weight loss on the HP diet. In contrast, there was a decrease in the percentage of lean body mass with weight loss on the HC diet although the percentage of fat body mass did decline as expected. Importantly, both metabolic parameters and inflammation markers were improved only on the high protein / reduced carbohydrate, moderately calorically restricted diet.

    Doesn't Eating Fat Make You Fat?
    Keeping weight off after a diet is the real challenge. The fact that in dieting it is mostly the caloric restriction that leads to weight loss and not diet specifics has been known for decades.2 For instance, in 1996 a study was published that compared diets much more disparate than the one described above.3 Forty-three obese adults were randomly assigned to receive diets containing 1,000 calories/day composed of either 32 percent protein, 15 percent carbohydrate, and 53 percent fat or 29 percent protein, 45 percent carbohydrate, and 26 percent fat. There was no significant difference in the amount of weight lost. Nevertheless, just as in the study above, fasting plasma glucose, insulin, cholesterol, and triacylglycerol concentrations decreased significantly in patients eating low-energy diets that contained 15 percent carbohydrate, but neither plasma insulin nor triacylglycerol concentrations fell significantly in response to the higher carbohydrate diet.

    A more recent study looked at moderate energy intake on a very high-fat, low-carbohydrate (73 percent of energy from fat, 10 percent of energy from carbohydrate and 17 percent of energy from protein) or low-fat, high-carbohydrate (30 percent of energy from fat, 53 percent of energy from carbohydrate and 17 percent of energy from protein) diet for 12 weeks.4 Unlike most modern diets, these were diets involving only minimally processed carbohydrates and fats. Despite expectations, the high fat diet did not raise LDL cholesterol; however, it did raise HDL cholesterol. According to one of the co-authors of the study, "the very high intake of total and saturated fat did not increase the calculated risk of cardiovascular diseases." "Participants on the very-high-fat diet also had substantial improvements in several important cardiometabolic risk factors, such as ectopic fat storage, blood pressure, blood lipids (triglycerides), insulin and blood sugar."5

    Therapeutic diets usually restrict either carbohydrates or fats. If fats are restricted, then the diet will tend towards an increased protein content. Most dieters will find that in the early stages, this high intake of protein will reactivate the thyroid and make life easier. There is plenty of clinical evidence to the effect that high protein snacks reduce calorie intake more than do snacks of carbohydrate, fat or alcohol for overweight individuals accustomed to the usual American mixed diet. And increasing protein intake to 25 percent of calories clinically has been demonstrated to increase both weight loss (by 75 percent) and fat loss (by 57 percent) more than was found on a protein intake of 12 percent. Still, eating protein is not a panacea (too much is too much6) and protein needs to be matched with goodly intakes of fruit and vegetables as well as the avoidance of refined carbohydrates for best results. Moreover, decades of research, as indicated above, demonstrates that carbohydrates need to be replaced by protein for best results.

    Does Gut Bacteria Play a Role in Weight Regain?
    Preserving lean tissue and improving various metabolic parameters certainly help to make dieting results more stable and lasting. An additional factor, one seldom considered, is the role of gastrointestinal bacteria in weight maintenance. Human experiments have demonstrated that changing the diet to artificially induce blood sugar regulation issues surprisingly quickly results in changes in the gut microbiome that cause these bacteria to release more calories from food than normally would be the case, for instance, by digesting supposedly indigestible fiber. Similarly, it is well established that individuals who are overweight, obese and/or diabetic often have substantially different gut microflora than individuals who are lean.7 Therefore, so-called yo-yo dieting and recurrent obesity might be at least influenced by the microbes found in the gut.

    A recent report in Nature casts further light on an aspect of this issue.8 As observed by one of the authors, Dr. Eran Elinav from the Weizmann Institute of Science in Israel, "we've shown in obese mice that following successful dieting and weight loss, the microbiome retains a 'memory' of previous obesity." Co-author Professor Eran Segal elaborated, "this persistent microbiome accelerated the regaining of weight when the mice were put back on a high-calorie diet or ate regular food in excessive amounts." One of the findings of this research is that the post-diet gut biome destroys certain flavonoids from the diet that influence energy metabolism. This interferes with energy release from fat. In post-dieting mice this leads to an accumulation of extra fat when they are returned to a higher-calorie diet. Experimentally, according to the paper, "flavonoid-based 'post-biotic' intervention ameliorates excessive secondary weight gain." This suggests that microbiome-targeting approaches may help with weight regain.

    Putting It Together
    Diets similar to the 30 percent protein, 30 percent fat, 40 percent carbohydrate diet described above have been proposed for several decades.9 In addition, the role of phytonutrients now is strongly supported. Both these aspects of good meal planning need to be addressed. A simple approach to meals is to make sure that roughly one third of the plate is covered with a protein source and one half or even two thirds of the meal plate is covered with the lightly cooked vegetable of your choice (salad does not count here; corn and carrots are counted as carbohydrates). Always eat this vegetable serving, which should be at least two cups of vegetables. Eat protein before eating any carbohydrates in the main meal for better digestion and better appetite control. (Classic European, Chinese and Japanese meal planning often arranges protein courses before carbohydrate courses.) Remember that vegetables are perfectly good carbohydrate sources and may well be consumed in the place of concentrated carbohydrates, such as rice and potatoes. Dieters also should consider supplementing with probiotics in conjunction with prebiotics. Finally, as noted in previous TotalHealth articles, when meals are eaten may be as important and what is eaten; never skip breakfast and avoid eating late in the evening or before bedtime.10

    References
    1. 1. Stentz FB, Brewer A, Wan J, Garber C, Daniels B, Sands C, Kitabchi AE. Remission of pre-diabetes to normal glucose tolerance in obese adults with high protein versus high carbohydrate diet: randomized control trial. BMJ Open Diabetes Res Care. 2016 Oct 26;4(1):e000258.
    2. 2. Sacks FM, Bray GA, Carey VJ, Smith SR, Ryan DH, Anton SD, McManus K, Champagne CM, Bishop LM, Laranjo N, Leboff MS, Rood JC, de Jonge L, Greenway FL, Loria CM, Obarzanek E, Williamson DA. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009 Feb 26;360(9):859–73.
    3. 3. Golay A, Allaz AF, Morel Y, de Tonnac N, Tankova S, Reaven G. Similar weight loss with low- or high-carbohydrate diets. Am J Clin Nutr. 1996 Feb;63(2):174–8.
    4. 4. Veum VL, Laupsa-Borge J, Eng Ø, Rostrup E, Larsen TH, Nordrehaug JE, Nygård OK, Sagen JV, Gudbrandsen OA, Dankel SN, Mellgren G. Visceral adiposity and metabolic syndrome after very high-fat and low-fat isocaloric diets: a randomized controlled trial. Am J Clin Nutr. 2016 Nov 30. pii: ajcn123463. [Epub ahead of print]
    5. 5. University of Bergen. "Saturated fat could be good for you, study suggests." ScienceDaily. ScienceDaily, 2 January 2017. www.sciencedaily.com/releases/2016/12/161202094340.htm.
    6. 6. Rietman A, Schwarz J, Tomé D, Kok FJ, Mensink M. High dietary protein intake, reducing or eliciting insulin resistance? Eur J Clin Nutr. 2014 Sep;68(9):973–9.
    7. 7. Zhang Q, Wu Y, Fei X. Effect of probiotics on body weight and body-mass index: a systematic review and meta-analysis of randomized, controlled trials. Int J Food Sci Nutr. 2015 Aug;67(5):571–80.
    8. 8. Thaiss CA, Itav S, Rothschild D, Meijer M, Levy M, Moresi C, Dohnalová L, Braverman S, Rozin S, Malitsky S, Dori-Bachash, M. Kuperman Y, Biton I, Gertler A, Harmelin A, Shapiro H, Halpern Z, Aharoni A, Segal E, Elinav E. Persistent microbiome alterations modulate the rate of post-dieting weight regain. Nature. 2016 Nov 24. doi:10.1038/nature20796.
    9. 9. Sears B, Ricordi C. Anti-inflammatory nutrition as a pharmacological approach to treat obesity. J Obes. 2011;2011.
    10. 10. Sellix MT. For Management of Obesity and Diabetes: Is Timing the Answer? Endocrinology.2016 Dec;157(12):4545–9.
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