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Impossible Weight-Loss Claims:
Summary of an FTC Report

Stephen Barrett, M.D.


Despite unprecedented levels of law enforcement by the Federal Trade Commission, deceptive weight-loss advertising is rampant. In response to the problem, the agency has identified seven claims that, based on current scientific knowledge, are impossible to fulfill and therefore should be rejected by responsible advertising outlets. The agency's conclusions have been published in a December 2003 staff report called Deception in Weight-loss Advertising Workshop' Seizing Opportunities and Building Partnerships to Stop Weight Loss Fraud. Here's the FTC list plus the report's analysis of each claim. (In a few cases, I have slightly modified the FTC's wording.)


False Claim #1. The product causes weight loss of two pounds or more a week for a month, or more without dieting or exercise.

FTC Staff Analysis: The FTC has considerable experience with claims that users can lose substantial weight without diet or exercise. For example, in FTC v. SlimAmerica, the FTC challenged claims that a product called Super Formula (which contained chromium picolinate, hydroxycitric acid, chitin, and glucomannan) could cause dramatic weight loss, including as much as 49 pounds in 29 days [1] The court, after hearing from experts on both sides, concluded:

To lose one pound of weight, according to a credible expert, the average individual needs a deficit of approximately 3,500 calories between caloric intake and caloric output. Although drugs may make it easier to achieve this deficit, they cannot alter this basic equation. Thus, it would be impossible for a person who did not diet or exercise to lose weight simply by taking the defendant's drug or weight loss product. It is thus elementary that if a person consumed calories in excess of his/her daily needs, and did not diet or exercise there would be weight increase, rather than decrease [2]

Theoretically, products purporting to cause weight loss without diet or exercise would either need to cause malabsorption of calories or to increase metabolism (so-called "thermogenic agents"). The number of calories that can be malabsorbed appears to be limited to 1200 to 1300 calories per week, or roughly one-third of a pound per week, at best. Accordingly, malabsorption alone is unlikely to lead to substantial weight loss [3]

With regard to thermogenic agents, it is often difficult to evaluate the supporting evidence, given the lack of rigorous methodology in many of the studies in question [4]. In any event, the effect of purported metabolism boosters appears to be very limited. For example, a study of green tea extract found only a 4% increase in metabolism [5]. Ephedrine, usually sold in combination with caffeine, has been one of the most popular thermogenic agents marketed over the past five years. It appears to produce only modest weight loss, mostly due to its appetite suppression effect [6].

The significance of the small amount of weight that can be lost through malabsorption or increased metabolism is debatable. It is clear, however, that as the amount of claimed weight loss increases, the likelihood that such weight loss can be achieved without restricting caloric intake or increasing exercise decreases dramatically. For example, weight loss in the range of two pounds per week over periods of time beyond four weeks (eight or more pounds per month) would require a net caloric deficit of 7,000 calories per week, or a 1,000 calories per day, over an extended period of time. That would amount to 40% of the total calories consumed per week on a 2,500 calorie per day diet [7]. As noted below, about 180 calories per day appears to be the outer limit for malabsorption. In addition, the staff is unaware of any scientific literature suggesting that 40% increases in metabolism can be achieved without producing toxic effects on the body.

In summary, the amount of weight loss that can be achieved through the use of nonprescription products without reducing caloric intake or increasing exercise is likely to be no more than one-fourth to one-third of a pound per week, with additional weight loss being attributable to reduced caloric intake. Accordingly, weight loss in the range of two pounds per week over periods of time beyond four weeks (eight or more pounds per month) without restricting caloric intake or increasing exercise is not now scientifically feasible [8]. (Ads that claim weight loss of less than two pounds per week without dieting or increasing exercise may still be false or unsubstantiated. The FTC chose the two-pounds-per-week level solely for the purpose of establishing a performance limit that is beyond reasonable scientific debate.)

False Claim #2. The product causes substantial weight loss, no matter what or how much the consumer eats.

FTC Staff Analysis: This claim is largely a variation of the claim that users can lose weight without reducing caloric intake or increasing exercise, because the essence of the claim is that users can lose weight without reducing caloric intake and may even increase caloric intake and still lose weight. This would defy the laws of physics. Accordingly, for the reasons set forth in the discussion of Claim #1, the claim that users can lose substantial weight while still enjoying unlimited amounts of high calorie foods is not scientifically feasible.

False Claim #3 The product causes permanent weight loss (even when the consumer stops using the product).

FTC Staff Analysis: Assuming that a product causes weight loss through a reduction of calories, through either an appetite suppression or malabsorption mechanism, weight would be regained once the intervention stops and calorie consumption returns to pre-intervention levels. In fact, it is well established that most people who lose weight gain it back within five years. Experts have repeatedly observed that although persons generally lose weight while actively participating in treatment, they tend to regain the weight over time once treatment ends [9]. According to the National Academy of Science, Food and Nutrition Board, "Many programs and services exist to help individuals achieve weight control. But the limited studies paint a grim picture: those who complete weight-loss programs lose approximately 10 percent of their body weight only to regain two-thirds of it back within 1 year and almost all of it back within 5 years." [10] Finally, no long-term studies on the weight loss maintenance of any of the covered products have been brought to the staff's attention, and we are not aware of any such studies in the published literature [11] Accordingly, a claim that a nonprescription drug, dietary supplement, cream, wrap, device, or patch can cause permanent weight loss is not scientifically feasible [12].

False Claim #4. The product blocks the absorption of fat or calories to enable consumers to lose substantial weight.

FTC Staff Analysis: The biological facts do not support the possibility that sufficient malabsorption of fat or calories can occur to cause substantial weight loss. To lose even one pound per week would require the malabsorption of about 500 calories a day or about 55 grams of fat [13]. To lose two pounds per day, as stated in the sample ad, would require the malabsorption of 7000 calories per day, which is impossible given that it is several times the total calories that most people consume on a daily basis, let alone the number of calories consumed from just fat [14]. The FTC has challenged a number of deceptive fat blocker claims for some of the most popular diet products on the market [15], and the evidence supports the position that consumers cannot lose substantial weight through the blockage of the absorption of fat [16]. Based on its past experience, as well as the discussion at the workshop, written comments, and published studies, the staff concludes that the claim that a nonprescription drug, dietary supplement, cream, wrap, device, or patch will cause substantial weight loss through the blockage of absorption of fat or calories is not scientifically feasible.

False Claim #5. The advertised product enables consumers to lose more than three pounds per week for more than four weeks.

FTC Staff Analysis: There are significant health risks associated with medically unsupervised, rapid weight loss over extended periods of time [17]. This conclusion does not mean that every person who loses more than three pounds per week will suffer serious side effects, but it does mean that weight loss in this range can create medical risks. In general, "the more restrictive the diet, the greater are the risks of adverse effects associated with weight loss." [10] One of the best documented risks is the increased incidence of gallstones [17]. Added to this risk is the fact that a covered product could be sold as part of a "program" that includes a very-low-calorie diet and that very low calorie diets can be nutritionally inadequate and result in serious injury or even death [18] Based on the discussion at the workshop, written comments, and the published literature, the claim that consumers who use one of the covered products without medical supervision can safely lose more than three pounds per week for a period of more than four weeks is not scientifically feasible.

False Claim #6. The product causes substantial weight loss for all users.

FTC Staff Analysis: Although there are common characteristics among the relevant population, there is not just one cause of overweight or obesity. In some people, the cause may be more closely linked to genetic factors, while in other instances, the principal causal factor may be environmental. Moreover, it should be obvious that diets, metabolic rates, and levels of physical activity vary from one individual to another and that compliance levels will vary. Even approved drugs for weight loss always have a high level of nonresponders, and even gastric surgery for obesity is not successful 100 percent of the time. Thus a claim that a nonprescription drug, dietary supplement, cream, wrap, device, or patch will cause substantial weight loss for all users is not scientifically feasible.

False Claim #7. The product causes substantial weight loss by wearing it on the body or rubbing it into the skin.

FTC Staff Analysis: The products at issue for this claim include creams, wraps, patches, earrings, shoe inserts, and rings, among others, that can be purchased without a medical prescription. Examples include, "Lose two to four pounds daily with the Diet Patch," and "Thigh Cream drops pounds and inches from your thighs." Based on the investigative experience of FTC staff, as well as the discussion at the workshop, written comments, and the published literature, a claim that users can lose substantial weight though the use of the advertised product that is worn on the body or rubbed into the skin is not scientifically feasible.

Endnotes

  1. FTC v. SlimAmerica, Inc., 77 F. Supp. 2d 1263 (S.D. Fla. 1999). See also FTC v. Slim Down Solution, LLC, No. 03-80051-CIV-PAINE (S.D. Fla. filed Jan. 24, 2003); FTC v. Mark Nutritionals, Inc., No. SA02CA1151EP (W.D. Tex. filed Dec. 5, 2002); FTC v. No. 9068- 8425 Quebec, Inc. d/b/a Bio Lab, No. 1:02:CV-1128 (N.D.N.Y. July 28, 2003) (stipulated final judgment); National Dietary Research, 120 F.T.C. 893 (1995) (consent order); Body Wise Int'l, 120 F.T.C. 704 (1995) (consent order); Taleigh Corp., 119 F.T.C. 835 (1995) (consent order); FTC v. Shell, No. 90 0120 (Kx) (C.D. Cal. Apr. 8, 1991) (stipulated permanent injunction).
  2. 77 F. Supp. 2d at 1273.
  3. One expert on the panel referred to a 1984 study of glucomannan that reported weight loss of 5.5 pounds over 8 weeks without any changes in diet or physical activity. Walsh, D.E., et al., Effect of Glucomannan on Obese Patients: A Clinical Study, 8 International Journal of Obesity 289-93 (1984). In this study, patients were instructed not to deviate from their previously established eating and exercise patterns. This study is not particularly persuasive given the small number of subjects in the treatment group (10) and the fact that subjects did not maintain appropriate food diaries. There is no way to be sure that subjects did not change eating patterns. In fact, one of glucomannan's purported mechanisms of action is as a bulking agent, and the authors note it "added bulk in the stomach just before each meal, [which] may decrease the appetite and [cause subjects] to eat less at each meal." Id. at 292.
  4. See generally Allison, D.B., et al., Alternative Treatments for Weight Loss: A Critical Review, 41 Critical Reviews in Food Science and Nutrition 1, 2-3, 18-20 (2001). One common problem in studies cited to support claims of weight loss without reducing caloric intake is the lack of any monitoring of caloric intake in those studies. See, e.g., Walsh (cited in note 4).
  5. See Dulloo, A.G. et al., Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans, 70 Am J Clin Nutr 1040-45 (1999) (comparing 24 hour energy expenditure in subjects given either caffeine, green tea extract (including caffeine), or placebo); see also Green Tea for Weight Loss?, Tufts Univ. Health & Nutrition Letter, June 2003, at 3, quoting Jeffrey Blumberg, PhD: "It can't be concluded that [the] small increase in metabolism" reported in studies on green tea, "'that could easily be undone by eating a single cookie or a handful of chips,'" could lead to weight loss.
  6. A recently released analysis indicates that there is scientific support that supplements containing ephedra and caffeine-containing herbs or ephedrine plus caffeine may cause weight loss of about 1/2 pound per week over four to six months. Evidence Report/Technology Assessment, Number 76, Ephedra and Ephedrine for Weight Loss and Athletic Performance Enhancement: Clinical Efficacy and Side Effects, U.S. Department of Health and Human Services, Agency for Healthcare Research and Quality, Feb. 28, 2003, at 219. It is not entirely clear how much of this modest effect is due to increased metabolism and how much is due to appetite suppression, but it has been estimated that at least half of the effect is due to appetite suppression. See Tr. at 90 (Anthony Almada and Dr. Steven Heymsfield). Some ephedrine studies have reported a 10% increase in metabolic rate. See Greenway, F.L., The safety and efficacy of pharmaceutical and herbal caffeine and ephedrine use as a weight loss agent, The International Association of the Study of Obesity, 2 Obesity Reviews 3:199-211, 202 (2001). In any event, the effect, if any, without also reducing caloric intake would appear to be quite limited. For example, one ephedrine and caffeine study found that 75 percent of the weight loss was explained by anorexia and 25 percent by increased thermogenesis. See id. at 204.
  7. American men and women consume, on average, about 2800 and 1800 calories per day, respectively, but there are large variations based on body size and other factors. Kathleen Melanson and Johanna Dwyer, Popular Diets for Treatment of Overweight and Obesity, in Handbook of Obesity Treatment 250 (Thomas A. Wadden and Albert J. Stunkard eds., New York: The Guilford Press, 2002).
  8. The specification of two pounds in this claim is conservative. The scientific literature does contain reports of studies that claim to have tested certain ingredients without diet or exercise. Two pounds of weight loss per week over a period of four weeks (eight pounds per month), however, significantly exceeds the results reported in these studies and would still include the most obviously exaggerated claims. It also would take into account temporary fluid loss during the initial week to 10 days. It should be emphasized, however, that ads that claim weight loss of less than two pounds per week without dieting or increasing exercise may still be false or unsubstantiated. The two pounds per week level is used here solely for the purpose of establishing a performance limit that is beyond reasonable scientific debate.
  9. Methods for Voluntary Weight Loss and Control, NIH Technol. Assess. Conf. 1992 Mar. 30-Apr. 1; 10.
  10. Thomas, P.R., ed., Weighing the Options: Criteria for Evaluating Weight-Management Programs 1 (National Academy Press 1995).
  11. The FTC has challenged weight loss maintenance/permanent weight loss claims as deceptive in a number of cases, including most recently, FTC v. USA Pharmacal Sales, Inc., No. 8:03-CV- 1366-T-23-EAJ (M.D. Fla. July 2, 2003) (stipulated final judgment), FTC v. Mark Nutritionals, Inc., No. SA02CA1151EP (W.D. Tex. filed Dec. 5, 2002), and FTC v. No. 9068-8425 Quebec, Inc. d/b/a Bio Lab, No. 1:02:CV-1128 (N.D.N.Y. July 28, 2003) (stipulated final judgment).
  12. It may not be possible to determine without further investigation whether a more explicit claim that users can maintain weight loss as long as they continue using a particular product is false or unsubstantiated. Therefore, this type of claim cannot be rejected on its face as not being scientifically feasible. Nonetheless, it could still be deceptive depending on the substantiation for the specific product.
  13. Even prescription drugs do not produce such dramatic results. For example, orlistat (XenicalTM) is an extensively studied pharmacological agent that produces malabsorption of approximately one-third of dietary fat in a meal. Louis J. Aronne, Treatment of Obesity in the Primary Care Setting, in Handbook of Obesity Treatment 390 (Thomas A. Wadden and Albert J. Stunkard eds., New York: The Guilford Press, 2002); see also George A. Bray, Drug Treatment of Obesity, in Handbook of Obesity Treatment 327 (Thomas A. Wadden and Albert J. Stunkard eds., New York: The Guilford Press, 2002) (discussion of orlistat response to treatment rates). Beyond this amount, users experience significant gastrointestinal disturbance, including loose stool and diarrhea. See Bray at 328-29; Aronne at 390. On a 60 grams of fat per day diet, approximately 180 calories per day would not be absorbed, resulting in weight loss of approximately onethird of a pound per week. By itself, this amount of weight loss would not be substantial, as that term is used here. See Tr. at 60-61, 62, 66, and 67. The evidence of significant weight loss achieved through agents such as orlistat is based on use of the agent in combination with a restricted calorie diet. For example, used in combination with a low calorie diet, orlistat has been reported to result in an 8% weight loss after a year compared with 4% in a control group. The control group was also on a low calorie diet. See Aronne at 390. Thus, the weight loss is not attributable to blocking the absorption of fat alone.
  14. Tr. at 60 (Dr. Judith Stern). Seven thousand calories represents approximately 750 grams of fat daily. On a 2,500 calorie per day diet consisting of 40% fat, a person would consume only about 110 grams of fat.
  15. See, e.g, FTC v. Enforma Natural Prods., Inc., No. 00-4376JSL (Cwx) (C.D. Cal. Apr. 25, 2000) (stipulated final judgment) ($10 million in consumer redress); FTC v. Slim Down Solution, LLC, No. 03-80051-CIV-PAINE (S.D. Fla. filed Jan. 24, 2003); FTC v. KCD Inc., 123 F.T.C. 1535 (1997) (consent order).
  16. See Gades, M.D. and Stern, J.S., Chitosan Supplementation and Fecal Fat Excretion in Men, 11 Obesity Research 683-88 (May 2003); Gades, M.D. and Stern, J.S., Chitosan supplementation does not affect fat absorption in healthy males fed a high-fat diet, a pilot study, 26 International Journal of Obesity 119-133 (2002); Pittler, M.H., et al., Randomized, double-blind trial of chitosan for body weight reduction, 53 European Journal of Clinical Nutrition, 379- 81 (1999); Wuolijoki, E., et al., Decrease in Serum LDL Cholesterol with Microcrystalline Chitosan, 21 Methods Find. Exp. Clin. Pharacol., 357-61 (1999); and Ho, S.C., et al., In 44 the Absence of Dietary Surveillance, Chitosan does not Reduce Plasma Lipids or Obesity in Hypercholesterolaemic Obese Asian Subjects, 42 Singapore Med J, 1: 6-10 (2001).
  17. Weighing the Options at 115-17 (cited in note 11); Edward W. Gregg and David F. Williamson, The Relationship of Intentional Weight Loss to Disease Incidence and Mortality, in Handbook of Obesity Treatment 126-27 (Thomas A. Wadden and Albert J. Stunkard eds., New York: The Guilford Press, 2002). The indication of four weeks is made here to distinguish short term, e.g., weekend, crash diets.
  18. Wadden, T.A., et al., "The Cambridge Diet: More Mayhem?" 250 JAMA 2833 (1983).

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This article was posted on December 16, 2003.