Abstract
Efficacy of weight loss and maintenance therapies in obesity is difficult to quantify due to continuous weight changes over time. We assessed a single exponential model of weight changes during selected non-surgical therapies of non-diabetic obese subjects. We analyzed published mean weight data from 6 studies of ≥12 weeks duration, with comparable treatment groups, and ≥4 weight measurements during very low carbohydrate or fat diets, or treatment with Lorcaserin, Sibutramine or Orlistat. We fit data to a single exponential model to estimate maximum predicted weight loss or regain and duration of weight loss or regain for each therapy. A single exponential is the appropriate model as determined by Kolmogorov-Smirnov, constant variance, and Durbin-Watson tests. Validity of parameter estimates was indicated by coefficients of variation <25%. Sensitivity analysis showed that weight regain at the end of the weight loss phase affected parameter estimates in some instances, with variations of weight loss of 0.2–0.7% of basal. Estimated weight loss and regain were similar to observed weight changes in all studies. The model could also be used to assess dose-response relationships. Estimates from the model were used to compare concurrent obesity regimens using 95% confidence intervals, taking into account pre-determined minimal clinically important differences. This exponential model may provide accurate estimates of maximum achievable weight loss or regain and optimal duration of efficacy for a variety of non-surgical weight loss and maintenance regimens from published mean weight data and may be useful to more accurately evaluate weight loss and maintenance regimens.
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The Global Challenge of Obesity and the International Obesity Task Force. [cited 2012March 11]; Available from: http://www.iuns.org/features/obesity/obesity.htm#Interna tional%20Obesity%20Task%20Force.
Ogden CL, Carroll MD, Curtin LR, et al. Prevalence of overweight and obesity in the United States, 1999-2004. JAMA 2006; 295: 1549–55.
Li Z, Maglione M, Tu W, et al. Meta-analysis: pharmacologic treatment of obesity. Ann Intern Med 2005; 142: 532–46. Epub 2005/04/06.
Greenway FL, Bray GA. Combination drugs for treating obesity. Curr Diab Rep 2010; 10: 108–15. Epub 2010/04/29.
Ioannides-Demos LL, Piccenna L, McNeil JJ. Pharmacotherapies for obesity: past, current, and future therapies. J Obes 2011; 2011:179674. Epub 2010 Dec 12.
Makoundou V, Bobbioni-Harsch E, Gachoud JP, et al. A 2-year multifactor approach of weight loss maintenance. EatWeight Disord 2010; 15: e9–14.
Sjostrom L, Rissanen A, Andersen T, et al. Randomised placebo-controlled trial of orlistat for weight loss and prevention of weight regain in obese patients. European Multicentre Orlistat Study Group. Lancet 1998; 352: 167–72.
Smith SR, Weissman NJ, Anderson CM, et al. Multicenter, placebo-controlled trial of lorcaserin for weight management. N Engl J Med 2010; 363: 245–56.
Davidson MH, Hauptman J, DiGirolamo M, et al. Weight control and risk factor reduction in obese subjects treated for 2 years with orlistat: a randomized controlled trial. JAMA 1999; 281: 235–42.
Brehm BJ, Seeley RJ, Daniels SR, et al. A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab 2003; 88: 1617–23.
Smith SR, Prosser WA, Donahue DJ, et al. Lorcaserin (APD356), a selective 5-HT(2C) agonist, reduces body weight in obese men and women. Obesity (Silver Spring) 2009; 17: 494–503. Epub 2008/12/06.
Bray GA, Blackburn GL, Ferguson JM, et al. Sibutramine produces dose-related weight loss. Obes Res 1999; 7: 189–98.
Toplak H, Ziegler O, Keller U, et al. X-PERT: weight reduction with orlistat in obese subjects receiving a mildly or moderately reduced-energy diet: early response to treatment predicts weight maintenance. Diabetes Obes Metab 2005; 7: 699–708.
Larsen TM, Dalskov SM, van Baak M, et al. Diets with high or low protein content and glycemic index for weight-loss maintenance. N Engl J Med 2010; 363: 2102–13.
Krempf M, Louvet JP, Allanic H, et al. Weight reduction and long-term maintenance after 18 months treatment with orlistat for obesity. Int J Obes Relat Metab Disord 2003; 27: 591–7.
Finer N, James WP, Kopelman PG, et al. One-year treatment of obesity: a randomized, double-blind, placebo-controlled, multicentre study of orlistat, a gastrointestinal lipase inhibitor. Int J Obes Relat Metab Disord 2000; 24: 306–13.
Bray GA. There’s more than one way to skin a cat: response to “Reporting weight loss: is simple better?” Obesity (Silver Spring) 2010; 18: 651.
Bray GA, Bouchard C, Church TS, et al. Is it time to change the way we report and discuss weight loss? Obesity (Silver Spring) 2009; 17: 619–21.
Sharma AM, Karmali S, Birch DW. Reporting weight loss: is simple better? Obesity (Silver Spring) 2010; 18: 219.
Forbes GB. Weight loss during fasting: implications for the obese. Am J Clin Nutr 1970; 23: 1212–9.
Heymsfield SB, Thomas D, Nguyen AM, et al. Voluntary weight loss: systematic review of early phase body composition changes. Obes Rev 2010; 12: e348–61.
Forbes GB, Drenick EJ. Loss of body nitrogen on fasting. Am J Clin Nutr 1979; 32: 1570–4.
Heymsfield SB, Casper K, Hearn J, et al. Rate of weight loss during underfeeding: relation to level of physical activity. Metabolism 1989; 38: 215–23.
Heymsfield SB, Harp JB, Reitman ML, et al. Why do obese patients not lose more weight when treated with low-calorie diets? A mechanistic perspective. Am J Clin Nutr 2007; 85: 346–54.
Motulsky H. Intuitive Biostatistics. New York, Oxford University Press, 1995, pp 285–6.
Kaptein EM, Beale E, Chan LS. Thyroid hormone therapy for obesity and nonthyroidal illnesses: a systematic review. J Clin Endocrinol Metab 2009; 94: 3663–75.
Kaptein EM, Sanchez A, Beale E, et al. Thyroid hormone therapy for postoperative nonthyroidal illnesses: a systematic review and synthesis. J Clin Endocrinol Metab 2010; 95: 4526–34.
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Kaptein, E.M., Chan, L.S. & Kaptein, J.S. Assessment of maximum weight change and duration of therapeutic effect for non-surgical treatment of obesity using an exponential model. Eat Weight Disord 17, e234–e243 (2012). https://doi.org/10.3275/8631
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DOI: https://doi.org/10.3275/8631