Biological mechanisms and initial weight influence weight regain

Research presented at the 67th Congress of the Spanish Society of Endocrinology and Nutrition (SEEN) suggests that obesity may leave a molecular memory in cells. Dr. Ana Belén Crujeiras, an epigenomics researcher, explained that epigenetic modifications—which regulate gene function without altering DNA sequences—can affect appetite regulation, energy metabolism, inflammation, and adipose tissue function. These changes may explain why some individuals are more predisposed to regaining weight after loss.

Additionally, a study by the German Center for Diabetes Research (DZD) published in ‘Nature Reviews Endocrinology’ indicates that the impact of the ‘yo-yo effect’ depends heavily on an individual's starting weight. For those with established obesity, repeated weight cycles tend to return the body to a similar composition with minimal long-term changes in fat mass. However, for individuals with a normal weight but a genetic predisposition to obesity, these cycles may progressively increase the proportion of adipose tissue relative to lean tissue, raising the long-term risk of developing obesity.