Do your New Year resolutions include dieting? Have you ever gone on a diet successfully only to find that you returned to your original weight some time later? Have you ever blamed yourself for regaining the weight you worked so hard to lose? Well, blame no more.
Diets continue to be highly popular and to support highly lucrative industries. However, in the majority of people they just do not work.
Many systematic and carefully controlled studies have shown that the so called ‘life-style modification’ diets, where you try to change what you eat and how much you eat according to some recommendation, only work in the short-term. People may show significant weight loss in initial months, but most of this weight is regained in the majority of people in the following months or years.
Specifically, one study showed that the proportion of people who successfully and consistently maintained 100% of reduced weight during a 4 to 5 year period after diet completion was only 3% (Kramer et al., 1989). Another study showed that only 28% of people maintained a loss of at least 10% of initial body weight at 4 years (Christiansen et al., 2007). Finally, a recent meta-analysis in the US (a study that examines, re-analyses and evaluates the results of all similar, previous studies on a given topic) found that 4.5 years post the successful completion of hypocaloric diets, with or without exercise, only an average 3.2% reduction of initial weight was maintained (Anderson et al., 2001).
Of course, pursuing a healthy life-style and treating obesity are important goals. However, it is increasingly clear that lifestyle modification diets are not the answer to such goals. The exact physiological and psychological reason why weight loss is so hard to maintain remain unknown and are likely to be complex (e.g. Blomain et al., 2013; Sumithran & Proietto, 2013). A current influential hypothesis is that our organism has developed evolutionary prescribed mechanisms to protects us against weight loss more vigorously than from weight gain, in order to ensure that we survive during periods when food is scarce. The latter periods were more common throughout our history, and still are in many parts of the world. Thus, when we go on a diet our organism may assume we are starving and ensures we regain the weight as soon as possible. Thus, in countries were an abundance of food is available, and hundreds of companies compete for our appetitive attention, diets do not seem to be the answer to overeating and obesity. Wherever the future answer lies, blaming yourself for lacking the will power to maintain weight loss seems wholly unnecessary.
Anderson, J. W., Konz, E. C., Frederich, R. C. and Wood, C. L. (2001) Long-term weight-loss maintenance: a meta-analysis of US studies. Am. J. Clin. Nutr. 74, 579-584
Kramer, F. M., Jeffery, R. W., Forster, J. L. and Snell, M. K. (1989) Long-term follow-up of behavioral treatment for obesity: patterns of weight regain among men and women. Int. J. Obes. 13, 123-136.
Christiansen, T., Bruun, J. M., Madsen, E. L. and Richelsen, B. (2007) Weight loss maintenance in severely obese adults after an intensive lifestyle intervention: 2- to 4-year follow-up. Obesity 15, 413-420.
Blomain, E. S., Dirhan, D. A., Valentino, M. A., Kim, G. W., & Waldman, S. A. (2013). Mechanisms of Weight Regain following Weight Loss. ISRN Obesity, 2013, 210524. doi:10.1155/2013/210524
Sumithran, P & Proietto, J. (2013). The defence of body weight: a physiological basis for weight regain after weight loss. Clin. Sci. 124; 231-41.