Effects of food on cortisol and mood in vulnerable subjects under controllable and uncontrollable stress.

The aim of this study was to investigate whether in stress-prone subjects, carbohydrate-rich, protein-poor food (CR/PP) diminished depressive mood and a cortisol response under controllable as well as uncontrollable laboratory stress. Twenty-two subjects with high stress proneness (HS) and 23 subjects with low stress proneness (LS) participated in a controllable- and uncontrollable-stress experiment during either a CR/PP or protein-rich, carbohydrate-poor (PR/CP) diet. Both controllable and uncontrollable laboratory stress significantly increased pulse rate and skin conductance in HS and LS subjects, whereas uncontrollable stress increased feelings of depression, anger, tension, and fatigue and decreased feelings of vigor.

The bovine protein alpha-lactalbumin increases the plasma ratio of tryptophan to the other large neutral amino acids, and in vulnerable subjects raises brain serotonin activity, reduces cortisol concentration, and improves mood under stress.

Background: Increased brain serotonin may improve the ability to cope with stress, whereas a decline in serotonin activity is involved in depressive mood. The uptake of the serotonin precursor, tryptophan, into the brain is dependent on nutrients that influence the cerebral availability of tryptophan via a change in the ratio of plasma tryptophan to the sum of the other large neutral amino acids (Trp-LNAA ratio). Therefore, a diet-induced increase in tryptophan availability may increase brain serotonin synthesis and improve coping and mood, particularly in stress-vulnerable subjects.

Carbohydrate intake improves cognitive performance of stress-prone individuals under controllable laboratory stress.

Cognitive performance has been found to decline after exposure to stress, particularly in stress-prone subjects. The present study investigated whether a carbohydrate-rich, protein-poor (CR/PP) diet, which may enhance cerebral serotonin function in stress-prone subjects due to increases in the available tryptophan, improves the performance of stress-prone subjects after exposure to acute laboratory stress. Twenty-two high-stress-prone (HS) subjects and twenty-one low-stress-prone (LS) subjects aged between 19 and 26 years performed a memory scanning task after controllable and uncontrollable stress, following either a CR/PP diet or a protein-rich, carbohydrate-poor (PR/CP) isoenergetic diet.

Body size perception in anorexia nervosa: a signal detection approach.

This study investigated whether individuals with anorexia nervosa (AN) visualize themselves as fatter than they are because they perceive themselves as fatter. Females with AN who overestimated their own body size judged size differences between pictures of their own body, and then again of someone else's body. Signal detection analysis of the results showed no differences in perceptual sensitivity between the AN and normal and thin control groups.

Does carbohydrate-rich, protein-poor food prevent a deterioration of mood and cognitive performance of stress-prone subjects when subjected to a stressful task?

This study investigates whether in stress-prone subjects, carbohydrate-rich, protein-poor food (CR/PP) prevents a deterioration of mood and performance under uncontrollable laboratory stress conditions. The assumption was that in stress-prone subjects there is a higher risk of serotonin deficiency in the brain and that carbohydrates may prevent a functional shortage of central serotonin during acute stress, due to their potentiating effect on brain tryptophan. Twenty-four subjects with a high stress-proneness (HS) and 24 subjects with a low stress-proneness (LS) participated in an uncontrollable stress situation under both a CR/PP and a protein-rich, carbohydrate-poor (PR/CP) diet condition.