Macronutrient intake, plasma large neutral amino acids and mood during weight-reducing diets

Abstract

Influence of diet composition on mood during weight-reducing diets was studied in healthy young women of normal weight. A broad range of macronutrient intake was achieved by means of divergent dietary instructions for the composition of a 1,000 kcal per day diet adhered to for six weeks. Global mood during the last three weeks of the diet was significantly better in the "vegetarian" than in the "mixed" diet group. During this time a significant correlation was observed between relative carbohydrate intake and global mood (r = -0.74; p less than 0.01) and between the ratio of plasma tryptophan to other large neutral amino acids (a predictor of tryptophan flow into brain) and global mood (r = -0.52; p less than 0.05). Results suggest that group differences are related to differences in carbohydrate intake. It is hypothesized that impairment of central serotonergic function due to reduced tryptophan availability can prompt mood deterioration in situations of relatively low carbohydrate intake.

Low- and high-carbohydrate weight-loss diets have similar effects on mood but not cognitive performance

“…Therefore, it is likely that the effects of weight loss may have had dominant effects on mood that overshadowed any effect of diet composition. However, Schweiger et al (37) showed in normalweight young women that mood was significantly better after 6 wk of an energy-restricted diet higher in carbohydrate and lower in fat and protein. Hence, the possible protection of weight loss against any otherwise negative effects of dietary composition may be confined to overweight or obese persons.…”

A Multivariate Analysis of Red Blood Cell Membrane Transports and Plasma Levels of <i>L</i>-Tyrosine and <i>L</i>-Tryptophan in Depressed Patients before Treatment and after Clinical Improvement

“…So endogenous plasma tryptophan and tyrosine to large neutral amino acid (LNAA) ratios could modify, among many other functions, via respectively the serotoninergic and catecholaminergic pathways, the food se lection, food intake and energy balance [Möller, 1986b]. Relations between affective disorders and feeding be havior are complex [Möller, 1986a;Schweiger et al. 1986;Morley and Blundell, 1988].…”

Nutritional influences on cognitive function: mechanisms of susceptibility

“…Furthermore, Schweiger et al (1986a) found that better mood was associated with higher average 24-h plasma TRP : LNAA. Nevertheless, more chronic studies of this type are needed before definitive conclusions can be drawn: for instance, both mood and TRP : LNAA could be raised by poor compliance with the required energy restriction.…”

“…Despite these methodological caveats, two other studies have linked greater positive affect and less negative affect with chronic (9 d or 6 weeks) relatively high-carbohydrate and lowprotein intake (Schweiger et al 1986a;De Castro, 1987b), although performance was not measured. Furthermore, Schweiger et al (1986a) found that better mood was associated with higher average 24-h plasma TRP : LNAA.…”