Lost Weight Creeping Back Again? Your Hormones May Be To Blame

For those of you who may be engaged in a struggle to maintain your weight loss, there is good news (sort of) and, well, some potentially not-so-good-news from a study published yesterday in the New England Journal of Medicine.  The findings suggest that dieters who have regained weight are not just slipping back into old habits, but are struggling against a persistent biological urge.

Let’s start with the “sort of” good news: If you regain weight, your eating habits may not be entirely to blame. If the findings of this new study hold true, it may be your hormones kicking in after you lose weight, making you feel hungrier.   One hormone, leptin, which tells the brain how much body fat is present, fell by two-thirds immediately after the subjects lost weight. When leptin falls, appetite increases and metabolism slows. A year after the weight loss diet, leptin levels were still one-third lower than they were at the start of the study, and leptin levels increased as subjects regained their weight. Other hormones that stimulate hunger, in particular ghrelin, whose levels increased, and peptide YY, whose levels decreased, were also changed a year later in a way that made the subjects’ appetites stronger than at the start of the study.  So, while it’s really not good news, at least now you can be a little less hard on yourself if you regain some of your weight. It could be your hormones, not your habits, that are helping to put the pounds back on.

The bad news, clearly, is that this physiological mechanisim is not under your control. While this study was small and it is too early to draw any definitive conclusions, it is disheartening to think your body may be working very hard undo your weight loss success.  Why would your body rebel against weight loss? Researchers believe it may be an evolutionary holdover from earlier times, when weight loss could threaten survival and reproduction.

A key message of the study is that it’s better not to gain weight in the first place than to try to lose it.  But this does not help the millions of Americans who are struggling with weight.  A solution might be to restore hormones to normal levels by giving drugs after dieters lose weight. But it is too early to know if this would be effective.

Despite the findings of this study, it is important to keep in mind that many people DO lose weight and keep it off for the long term.  At Appetite for Health we highlight what works in the battle of the bulge.  Be encouraged by the successes of others.  With hard work and persistance, you too can achieve a healthy weight… but be prepared to continue working hard to keep it off for the long-term.



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