Rise of ketone bodies with psychosocial stress in normal weight men.

BACKGROUND Ketone bodies are known as alternative cerebral energy substrates to glucose. During psychosocial stress, the brain of a normal weight subject demands for extra glucose from the body to satisfy its increased needs. In contrast, the brain of an obese subject organizes its need, supply and demand in a low-reactive manner. The present study aimed at investigating (i) whether psychosocial stress increases ketone body concentrations and (ii) whether ketone reactivity to a psychosocial challenge differs between normal weight and obese people. METHODS Ten normal weight and ten obese men participated in two sessions (stress induced by the Trier Social Stress Test and a non-stress control session). Blood samples were frequently taken to assess serum β-hydroxybutyrate concentrations and stress hormone profiles. RESULTS Our main finding was that social stress markedly increased concentrations of serum β-hydroxybutyrate by 454% in normal weight men. The increase in ketone bodies during stress in normal weight subjects was associated with an increase in ACTH, norepinephrine and epinephrine concentrations. Interestingly, we could not detect any increase in serum β-hydroxybutyrate concentrations during stress in obese men. CONCLUSION Normal weight men showed high ketone reactivity to a psychosocial challenge.