Environmental, Familial, Neurohormonal Factors May Explain Obesity Epidemic

The Society for Neuroscience 2013 Annual Meeting hosted a mini-symposium called “Food for Thought” to explore multiple factors associated with obesity, including the environment’s role in obesity development, sedentary lifestyles and metabolic dysregulation, and the bidirectional relationship between the brain and peripheral signals and responses.

Over the past century, the availability of electric lighting has disrupted the previously tight connection between the external solar day and our daily activities, and growing evidence suggests changes in circadian light and dark cycles negatively affect human physiology and psychology. In particular, changes in leptin levels, glucocortioid metabolism, and the endocannabinoid system may be a cause of widespread obesity.

Speakers at the mini-symposium also covered the potential role of human ancestry in the obesity epidemic. While they acknowledged that nutrition across a patient’s lifespan directly influences the development of obesity, they noted that “nutritional effects” might affect future generations’ health and development, as research shows grandfathers’ food availability in early life is associated with the risk of diabetes, cardiovascular disease, and mortality in their grandsons.

While most clinicians currently acknowledge that weight gain and obesity are far more complicated than previous willpower-based models suggest, the presenters expanded the scientific insight on this topic. For example, some factors that increase a patient’s propensity to gain weight may be beyond his or her immediate control, such as the influence of neurohormonal signals on pathological changes in feeding circuitry.

The speakers concluded that they hope future research will better explain the interactions between the environment, human ancestry, and physiology as each relates to obesity.