Study links disrupted stress hormones to higher obesity risk

A new study from Weill Cornell Medicine reveals that obesity may stem from disruptions in the body's stress hormone rhythm, not just diet. The researchers found that disruptions to the daily pattern of glucocorticoid hormones, which control stress response and metabolism, can lead to obesity even without a high-fat diet. Mice exposed to these disrupted hormone rhythms accumulated fat mainly in adipose tissue, while liver fat accumulation was minimal.

In contrast, a high-fat diet resulted in overall fat buildup and significant liver fat accumulation. When both factors were present, the mice experienced the highest levels of fat accumulation. The study also showed that insulin resistance in mice with disrupted hormone rhythms primarily affected muscle tissue, allowing adipose tissue to continue storing fat.

This discovery supports a 2022 study by the same team, which found that disrupting glucocorticoid hormone rhythms caused significant fat gain in mice despite no increase in food intake. Human studies have linked disrupted cortisol rhythms to obesity, particularly in those experiencing chronic stress or irregular work hours. Study lead Dr. Mary Teruel emphasized that obesity is a multifaceted condition with various causes, and insulin resistance may differ based on the affected tissue and the underlying cause.

The researchers stressed the need to understand additional factors contributing to obesity, such as sleep disruption, stress, and the timing of hormonal signals, and called for further research to determine the applicability of these findings to humans.