Friday, August 2, 2019

Fad Diets: Look Before You Leap Essay

Association. â€Å"Fad diets are a short-term, quick-fix approach to weight loss that don’t work over the long haul. These diets tend to over-promise results but don’t deliver. Food choices are often monotonous, and caloric intake may be very restricted, so that once the novelty wears off, so does the motivation to continue.† Even the U.S. Department of Agriculture (USDA) has recognized the huge popularity of fad diets, and in February it sponsored the Great Nutrition Debate, a discussion panel that featured popular diet book authors as well as nutrition and weight loss researchers. While the panelists agreed that Americans are too fat, there was no consensus about the best way to lose weight and keep it off-although it led to interesting and sometimes heated debate. In the end, USDA indicated that it might be time for government researchers to evaluate the various diets to help sort fact from fiction. There is a dire lack of scientific research to corroborate the theories expounded in the majority of diet books currently on the market. Most promise weight loss programs that are easy, allow favorite foods or foods traditionally limited in weight loss diets without limitations, and do not require a major shift in exercise habits. Often, adds Sachiko St. Jeor, PhD, RD, Director of the Nutrition Education and Research Program at the University of Nevada School of Medicine, â€Å"fad diet book authors take a scientific half-truth that is complex and use that as the basis for their arguments.† Authors may simplify or expand upon biochemistry and physiology in an effort to help support their theories and provide a plethora of scientific jargon that people do not understand but that seems to make sense. And few, if any, offer solid scientific support for their claims in the form of published research studies. Instead, most evidence is based on anecdotal findings, theories, and testimonials of short-term results. Some of the most popular diets to hit the news wires these days are those that promote low carbohydrate and high protein intakes and promise significant weight loss. These diets are nothing more than low calorie diets in disguise, but with some potentially serious consequences. Following a low-carbohydrate, high-protein diet will encourage the body to burn its own fat. Without carbohydrates, however, fat is not burned completely and substances called ketones are formed and released into the bloodstream. Abnormally high ketone levels in the body, or ketosis, may indeed make dieting easier, since they typically decrease appetite and cause nausea. However, ketosis also increases the levels of uric acid in the blood, which is a risk factor for gout and kidney disease in susceptible people. Additionally, notes Dr. St. Jeor, â€Å"following these diets can result in dehydration, diarrhea, weakness, headaches, dizziness, and bad breath, and over the long term, can also increase risk of atherosclerosis and osteoporosis.† Here’s a rundown on some of the more popular high-protein, low-carbohydrate diets that are making headlines. Sugar Busters! By H. Leighton Steward, Sam S. Andrews, MD, Morrison C. Bethea, MD, and Luis A. Balart, MD Premise/Theory:Sugar and certain carbohydrates (those with high glycemic indices) are toxic to the body causing blood sugar levels to rise and increasing the levels of insulin production, thereby prompting fat storage and weight gain. Supposedly, decreasing sugar intake can help people lose weight and decrease body fat, no matter what other foods are eaten. Dietary Recommendations: * Eliminates refined and processed carbohydrates, especially sugar and white flour and all foods made from these ingredients. Also eliminates foods like potatoes, corn, white rice, beets, carrots, corn syrup, molasses, honey, soft drinks, and beer. * Encourages consumption of whole grains, low-glycemic-index carbohydrates (high-fiber vegetables and fruits), and lean meats with no restrictions on protein foods. * Authors claim that washing food down with liquid does not allow for proper chewing. Claims excess fluid with meals also dilutes digestive juices and can result in partially digested food. * Average intake of calories is 1200 calories/day distributed as 30 percent carbohydrate, 32 percent protein, and 28 percent fat. Recommended calorie intake in this diet is low, accounting for short-term weight loss. Concerns: * There is no scientific basis or published data for the Sugar Busters! weight loss theory. The explanation of insulin’s role in weight gain that is provided is simplistic. The body does produce insulin in response to a rise in blood sugar levels, but it does not promote storage of fat unless excess calories are consumed. * There is no scientific evidence supporting the claim that the consumption of fluids during meals negatively affects digestion. Drastically decreasing dietary intake of carbohydrates forces the body to burn reserves of stored fat for energy, a condition known as ketosis, which leads to decreased hunger and a metabolic advantage. Dietary Recommendations: * Limits carbohydrates to 20 grams/day for the induction phase of the diet and 0 to 60 grams/day in the ongoing weight loss phase. Carbohydrate intake ranges from 25 to 90 grams/day in the maintenance diet. * Unlimited quantities of protein foods and fat-steak, bacon, eggs, chicken, fish, butter, and vegetable oil-are allowed. Avoid or limit carbohydrates, specifically breads, pasta, most fruits and vegetables, milk, and yogurt. Concerns: * No published scientific studies support the diet claims. * Offers extremely limited food choices. Diet is nutritionally unbalanced and excessively high in protein, fat, saturated fat, and cholesterol. * Promotes ketosis as a means of weight loss. * Suggests that a high-saturated-fat, low-carbohydrate diet does not have an effect on lipids. * Dehydration is possible if large amounts of water are not consumed. * Diet is low in calcium, magnesium, potassium, vitamin C, and folate (dietary supplements are recommended). Enter the Zone By Barry Sears, PhD Premise/Theory: The â€Å"zone† is a metabolic state in which the mind is relaxed and focused and the body is strong and works at peak efficiency. A person in the â€Å"zone† will allegedly experience permanent body fat loss, optimal health, greater athletic performance, and improved mental productivity. Insulin is released as a result of eating carbohydrates and leads to weight gain. Because food has a potent, drug-like effect on the hormonal systems that regulate the body’s physiological processes, eating the right combination of foods leads to a metabolic state (lower insulin levels and lower eicosanoid levels) in which the body works at peak performance and which results in decreased hunger, weight loss, and increased energy. Dietary Recommendations: * To get into the â€Å"zone,† rigid quantities of food, apportioned in blocks and at prescribed times, are recommended in a distribution of 40 percent carbohydrate, 30 percent protein, and 30 percent fat. Meals should provide no more than 500 calories and snacks less than 100 calories. * Food should be treated like a medical prescription or drug. * Menus suggest lots of egg whites, nuts, olives, peanut butter, and monounsaturated fats and large amounts of allowable (low-glycemic-index) fruits and vegetables.Alcohol is okay in moderation, but â€Å"zone† followers are advised to avoid or limit carbohydrates, especially pasta, bread, high-glycemic-index fruits and vegetables such as carrots and bananas, saturated fat, and arachidonic acid. * Diet averages 1,300 calories per day, although some menus may run as low as 850 calories. Concerns: * Oversimplifies complicated physiological processes. For example, eicosanoids are one part of a complex system, and no studies suggest that they are dangerous or cause disease. * The metabolic pathways explained in the book that supposedly connect diet, insulin-glucagon, and eicosanoids are not found in standard nutrition or biochemistry texts. The premise that any type of diet completely controls insulin and glucagon secretion is not supported by current nutrition or biochemistry knowledge, nor is the theory that the insulin-glucagon axis controls production of eicosanoids. * Relies upon unproven claims based on case histories, testimonials, and uncontrolled studies that are not published in peer-reviewed journals. Although all of these diets may promote short term weight loss, their long term effectiveness is a different story. The bottom line for lasting and healthful weight loss is a varied diet, reduced caloric intake, and regular physical activity. â€Å"The truth is that losing weight permanently takes work. It’s not glamorous-eating habits need to change and activity usually needs to increase,† notes Quagliani. â€Å"If a diet sounds too good to be true, it probably is.† Glossary Arachidonic acid: fatty acid precursor for eiconsanoid production. Eicosanoids: biologically active class of compounds that are involved in a wide range of regulatory processes such as synthesis of certain fatty acids. Glycemic index: a ranking of the effect on blood glucose of the consumption of a single food relative to a reference carbohydrate (e.g., white bread or glucose). Glucagon: has an effect opposite to that of insulin. Insulin’s and glucagon’s opposing effects help maintain carbohydrate metabolism in a steady state. Tips on Spotting Fad Diets Claims or implies a large or quick weight loss of more than 1 to 2 pounds per week. Slow, gradual weight loss increases the chance of weight loss success and of keeping weight off over the long term. Promotes magical or miracle foods. No foods can undo the long-term effects of overeating and not exercising or melt away fat. Restricts or eliminates certain foods, recommends certain foods in large quantities, insists on eating specific food combinations, or offers rigid, inflexible menus. Implies that weight can be lost and maintained without exercise and other lifestyle changes. Relies heavily on undocumented case histories, testimonials, and anecdotes but has no scientific research to back claims. Contradicts what most trusted health professional groups say, or makes promises that sound too good to be true.

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