Many of those who have tried to lose weight through dieting have had a difficult time keeping the weight off once the diet ends, leading to what's called "yo-yo dieting" where the weight is continually lost and gained in a seemingly never-ending cycle. According to a recent study in published in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM), the reason for this may be due to the levels of appetite hormones in the body just before the diet is begun.
The hormones leptin and ghrelin regulate appetite in the body, and in most healthy people function interdependently. While ghrelin is a peptide that stimulates appetite, leptin is an appetite-suppressing one. Ghrelin particularly influences the metabolism of fat tissue by promoting its storage in the absence of caloric intake. Leptin produces a satiety signal and gives us a feeling of satisfaction.
The researchers studied a group of 104 overweight or obese volunteers, who undertook an 8-week diet program where they consumed 30% fewer calories than usual. They were evaluated again 32 weeks after the diet ended to see how much of the weight they had kept off. Body weight and fasting plasma levels of ghrelin, leptin and insulin were measured at the diet's beginning, end, and 32 weeks after the diet ended.
It was found that those who had higher levels of leptin and lower ghrelin levels before dieting began were more likely to regain the lost weight after dieting ended. The researchers believe that the levels of these hormones can act as biomarkers for predicting the success of obesity treatment
Lead author of the study, Ana Crujeiras, PhD, of Compejo Hospitalario Universitario de Santiago in Spain, said "Treating obesity with drugs or dietary programs can be very effective in the short-term, but the long-term success of maintaining the weight lost is usually poor. Our study sheds light on how the appetite hormones leptin and ghrelin affect weight regain after weight loss. This knowledge could be used as a tool to personalise weight-loss programs that could guarantee success in keeping off the weight."
"We believe this research is of foremost relevance in clinical terms as it may indicate that the outcome of weight therapy may be pre-conditioned," continued Crujeiras. "Furthermore, our findings may provide endocrinology and nutrition professionals a tool to identify individuals in need of specialised weight-loss programs that first target appetite hormone levels before beginning conventional dietary treatment."