The corpulent phenotype—how the brain maximizes survival in stressful environments

Abstract

The reactivity of the stress system may change during the life course. In many—but not all—humans the stress reactivity decreases, once the individual is chronically exposed to a stressful and unsafe environment (e.g., poverty, work with high demands, unhappy martial relationship). Such an adaptation is referred to as habituation. Stress habituation allows alleviating the burden of chronic stress, particularly cardiovascular morbidity and mortality. Interestingly, two recent experiments demonstrated low stress reactivity during a mental or psychosocial challenge in subjects with a high body mass. In this focused review we attempt to integrate these experimental findings in a larger context. Are these data compatible with data sets showing a prolonged life expectancy in corpulent people? From the perspective of neuroenergetics, we here raise the question whether “obesity” is unhealthy at all. Is the corpulent phenotype possibly the result of “adaptive phenotypic plasticity” allowing optimized survival in stressful environments?

Biological and psychological predictors of posttraumatic stress disorder onset and chronicity. A one-year prospective study

“…Peters et al. recently showed that exposure to chronic stress can result in two different phenotypes depending on genetic background (Peters et al., 2013). The A-phenotype accumulates visceral fat (high WHR) and does not habituate to chronic stress, whereas the B-phenotype, once exposed to a stressful environment, habituates but needs to increase food intake in order to maintain brain energy metabolism, subsequently accumulating peripheral fat (high BMI).…”

“…As habituation to stress reduces the damaging effects of chronic stress, the risk of developing cardiovascular, metabolic and certain psychiatric diseases (e.g. typical depression) in stressful environments associated with the B-phenotype, would be globally lower (Peters et al., 2013). On the other hand, the absence of habituation to stress in the A-phenotype has been linked to higher cortisol secretion during exposure to uncontrollable psychological stressors, notably in lean women (Epel et al., 2000).…”

Energy allocation between brain and body during ontogenetic development

“…Then the surplus of energy accumulates in the body periphery. At the expense of weight‐induced osteoarthritis and reduced physical mobility, however, these subjects benefit from a better overall health and longevity in stressful environments (Peters et al, ).…”

6thAnnual Symposium on Self-Monitoring of Blood Glucose (SMBG) Applications and Beyond, April 25–27, 2013, Riga, Latvia

“…53 An intrinsic ''brain pull'' mechanism ensures energy is offered first to the brain at the expense of the rest of the body. This mechanism is driven to a large extent by stress (sympathetic) stimuli.…”