Eating to dare - Nutrition impacts human risk decision and related brain function

Description: Macronutrient composition modulates plasma amino acids that are precursors of neurotransmitters and can impact brain function and decisions. Neurotransmitter serotonin has been shown to regulate not only food-intake, but also economic decisions. We investigated whether an acute nutrition-manipulation inducing plasma tryptophan fluctuation affects brain function, thereby manipulating risk-decisions. Breakfasts differing in carbohydrate/protein ratios were offered to test changes in risk decision-making while metabolic and neural dynamics were tracked. We identified that a high-carb/protein meal increased plasma tryptophan which precisely predicted individual risk-shift. Critically, the link between plasma tryptophan and risk-shift depended on individual’s fat-mass. Using fMRI, we further identified activation in the inferior parietal lobule during risk, of which activities 1) were sensitive to tryptophan fluctuation, 2) were modulated by individual’s body fat mass and 3) further predicted the risk-shift in decision-making. Our results provide evidence for a personalized nutrition-driven-modulation on human risk-decision and its metabolic and neural mechanisms.