Fad Diets: Do They Work? Medical Considerations. Jessica McCourt Masters Project Spring 2008 Gilbert Boissonneault. Outline. Introduction How to spot a fad diet Discussion of different fad diets Why fad diets “work” Why fad diets don’t “work” and medical considerations
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Fad Diets: Do They Work?Medical Considerations Jessica McCourt Masters Project Spring 2008 Gilbert Boissonneault
Outline • Introduction • How to spot a fad diet • Discussion of different fad diets • Why fad diets “work” • Why fad diets don’t “work” and medical considerations • Healthy eating and exercise
Introduction • American Obesity Association reports (AOA 2005) • 127 million US adults are overweight • 60 million are obese • 9 million are severely obese • Totaling over one-third of the adult American population • Obesity is associated with more than 30 medical conditions. • Including diabetes, osteoarthritis, coronary heart disease, respiratory problems, and hypertension. • Weight loss of about 10% of body weight can improve some obesity-related medical conditions.
Introduction • American Obesity Association • genetics • environmental exposure to an energy-rich food supply • a tendency to reduce physical activity and personal behavior • The American Dietetics Association • increased per capita caloric consumption • larger portion sizes • lack of adequate physical activity
Introduction • National obsession • Americans spend an astonishing $33 billion a year on weight loss plans and services • Consequently, fad diet plans that promise dramatic results have become very popular. • More than two-thirds of Americans are either dieting to lose weight or watching what they eat to keep from gaining weight • More than one in five dieters used fad diets
How to spot a fad diet • Fad diets can be quite convincing to the average person • Offer a quick solution to a long term problem • Author or creator presents what appear to be scientifically valid explanations to support the dieting theory. • The individual marketing or promoting the diet may be tertiary educated, although frequently has no formal nutrition or dietetic qualifications. • The theory is often explained using scientific terminology, which may or may not be understood by the consumer • Most of the "evidence" for fad diets is based on theories and testimonials of short term results.
Discussion of fad diets: Atkins • Limit the intake of starchy, high carbohydrate foods • Consuming more carbohydrate than can be used by the body it will store this excess in fat cells • Without carbohydrates however, fat is not burned completely and substances called ketones are formed • According to Dr. St. Jeor “abnormally high ketone levels in the body, or ketosis, may indeed make dieting easier since they typically decrease appetite and cause nausea. Ketosis also increases the levels of uric acid in the blood, which is a risk factor for gout and kidney disease in susceptible people” (Jeor 2000). • Atkins diet could lead to halitosis, constipation, heart disease, bone loss, colon cancer, and kidney damage
Discussion of fad diets: Zone • 40% carbohydrates, 30% protein, 30% fats • For many individuals this precise ratio is not feasible to follow for every meal of the day and would take a lot of preparation time • The diet is also a low calorie diet, so you can't help but lose weight. • According to Samuel Cheuvront, PhD, RD the precise protein to carbohydrate ratio required with each meal is promoted to ultimately produce a cascade of events leading to a reduction in chronic disease risk, enhanced immunity, increased longevity and permanent weight loss. • “A review of the literature suggests that there are scientific contradictions in the Zone Diet hypothesis that cast unquestionable doubt on its potential efficacy” (Cheuvront 2003).
Discussion of fad diets: Blood Group • This diet depends on having a blood test and determining your blood type • Different blood groups can eat different food groups. • For example the A group diet excludes dairy and meat products. Removing dairy products completely from the diet can lead to a calcium deficiency, which can put you at risk of osteoporosis. Avoiding meat can result in low intakes of iron, which can lead to anemia. In the long run, removing any food group entirely can result in a poor intake of nutrients which are needed for good health (Kellow 2007). • By eliminating whole food groups important nutritional deficiencies are likely associated with long term health problems.
Discussion of Fad Diets:Hay • Do not eat protein and carbohydrates together. • Combination of eating these two foods together appears to prevent protein from being digested in the gut and can lead to an accumulation of toxins. • A study performed at the University of Rostock in Germany “was to evaluate the metabolic effect of the Hay diet on protein turnover, fat oxidation, respiratory quotient, body fat and weight loss. Twelve healthy adults received an individually regular diet and thereafter a 10-day Hay diet. The Hay diet did not reduce total body water, lean body mass, body fat and body weight” (Wutzke 2001).
Discussion of fad diets: Cabbage soup/Grapefruit • Basically the same • Consume a specific food everyday for each meal. • Both have weight loss, but mainly because of the strict calorie restriction. • Weight loss is mostly 'water' weight. • The thing is who can stick to just eating cabbage soup or grapefruit for an extended period of time? • Once the diet is discontinued the weight will immediately be regained.
Why fad diets “work” • Work short term because calorie intake as a result of the diet is usually lower than the person's basal metabolic requirements. • This is the only way to lose weight: to consume less energy than the body needs. • The rate of weight loss varies depending on the relative proportions of the three major nutrients in the diet: carbohydrate, fat and protein. • This also includes shift in water weight. • The rate of anticipated weight loss will vary according to the age, sex, weight, basal requirements, and activity level of an individual.
Why fad diets don’t “work” and medical considerations • David Roberts, professor of Nutrition and Dietetics, says that “fad diets are generally nutritionally unbalanced and lack essential nutrients” (Roberts 2001). • When weight loss is too fast, especially the loss of lean body mass, this can cause obesity in the longer run. • One large study reported an overall increased risk of major weight gain in the long term in those who undertook weight-loss attempts (dieting) at baseline (Roberts 2001). • By omitting certain foods, and sometimes even entire food groups, these diets are deficient in major nutrients • Some of the diets are also out of balance
Why fad diets don’t “work” and medical considerations • All fad diets tend to promote the loss of water weight. • If an imbalanced diet is maintained, the body soon reverts to a fasting state called ketosis • The body is actually tricked into thinking it is a starvation mode. • Authors of many of these fad diets actually advocate "taking advantage" of ketosis to hasten weight loss. • Deliberately inducing ketosis can lead to muscle breakdown, nausea, dehydration, headaches, light-headedness, irritability, bad breath, and kidney problems. • In a randomized weight loss study comparing ketogenic and non-ketogenic low-calorie diets, the subjects on the ketogenic diet had impairments in higher order mental processing than those on the nonketogenic diet (Denke 2001).
Why fad diets don’t “work” and medical considerations • In the long run fad diets make a person fatter instead of leaner, because each time the diet is stopped it is easier to regain fat that was originally lost. • Perhaps what is most concerning about fad diets, regardless of whether they work, is that they could ultimately encourage unhealthy attitudes towards food and eating.
Healthy eating and exercise • Very simple dietary changes can produce effective weight loss at a healthy rate that can be maintained over the longer term. • Your starting weight, exercise level, and basal metabolic rate determine the total amount of calories that is right for your diet program. • Patients and their health care providers must be conscious of health concerns when choosing a plan for weight loss because dietary change is meant to be a long-term process (Ma 2007). • A “gradual and balanced” approach is best for those who really want to lose weight, said Vivian Crisman a nutritionist (Miller 2003) • Healthy lifestyle habits will help maintain long-term weight control, which includes regular aerobic and weight training exercise, behavior modification, and a healthy, nutritious diet with a wide variety of foods.
Healthy eating and exercise • The word diet originally comes from the Greek root meaning, "way of life." • Scientists and nutritionists agree that any long-term program of weight loss and maintenance must be more than a matter of for example removing carbohydrates and counting calories. It must extend to the entire "way of life."
References • Ahrens, Joseph and Daryl Thompson. The Grapefruit Solution: Lower Your Cholesterol, Lose Weight and Achieve Optimal Health with Natures Wonder Fruit. Great Falls, VA: Li Corp. 2004. • “Americans Fed Up With Diet Advice”. New York Times Jan 2, 2001. • American Obesity Association, “Health Effects of Obesity”. May 2, 2005, Available at: http://obesity1.tempdomainname.com/subs/fastfacts/Health_Effects.shtml, Accessed January 25, 2008. • Apovian, CM, Lenders CM. A Clinical Guide for Management of Overweight and Obese Children and Adults. CRC Series in Modern Nutrition. Boca Raton, FL: CRC Press: Part VI, Chapter 18, 223, 2006. • Atkins, Robert C. Dr. Atkin’s Diet Revolution. New York, New York: Bantam Books. 1972. • Bolen, Debby. “Fad Diets Can Be Ineffective and Dangerous.” October 30, 2007, Available at: www.newstrget.com, Accessed January 25, 2008. • Cheuvront, Samuel PhD, RD. The Zone Diet Phenomenon: A Closer Look at the Science behind the Claims. Journal of the American College of Nutrition. 22 (1): 9-17, 2003. • Cunningham, Eleese RD and Marcason, Wendy RD. Is it Possible to Burn Calories by Eating Grapefruit or Vinegar? Journal of the American Dietetic Association. 101 (10): 1198, 2001. • D’Amada, Peter and Catherine Whitney. Eat Right For Your Type: The Individualized Diet Solution to Staying Healthy, Living Longer, and Achieving Your Ideal Weight. New York, New York: Penguin Putan Inc. 1996. • Denke, Margo A. Dr. Metabolic Effects of High Protein, Low Carbohydrate Diets. The American Journal of Cardiology. 88: 56-61, 2001. • Donbrot, Margaret. The New Cabbage Soup Diet. New York, New York: St. Martins Press. 2004. • Eisenga, BH. PhD, MD, Judge BS MD. Disorders of Fuel Metabolism: Medical Complications Associated with Starvation, Eating Disorders, Dietary Fads, and Supplements. Emergency Medicine Clinics of North America. 23 (3): 797, 2005. • Goldberg, Jeanne P. PhD, RD. The obesity crisis: don’t blame it on the pyramid. Journal of American Dietetic Association. 104(7): 1141-1147, 2004.
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