Dietary leucine and alanine supplementation have similar effects in the prevention of high fat diet induced obesity

Abstract

High protein diets can alleviate detrimental effects of high fat diets as discussed to be partially due to Leu. C57BL/6 male mice were fed ad libitum for 1 wk with high‐fat diets (20% of fat) containing an adequate (10%, APD) or high (50%, HPD) amount of whey protein, or supplemented with Leu corresponding to the Leu content within the HP diet (LD) or supplemented equimolar with Ala (AD) in order to clarify the specificity of Leu effects. Food and water intake were monitored (computer controlled system). Body composition was assessed (QMR). HP completely prevented the AP induced accumulation of body fat. LD and AD resulted in similar reductions of body fat accumulation which was intermediate between AP and HP. Triacylglycerol concentrations and gene expression of lipogenic enzymes in liver as well as plasma cholesterol were lower by HP compared to AP, both LD and AD showed intermediate effects. Body fat gains correlated with total energy intake (P<0.0001). Water intake rapidly increased by HP feeding and correlated with total nitrogen intake (P<0.0001). Feed energy efficiency correlated with energy intake (P<0.0001). We concluded that the positive effects of high protein diets on metabolic syndrome associated traits are mainly due to effects on satiety linked to amino‐N intake. There is no specific metabolic effect of Leu at least in the short term. Grants PE643/7‐1, PE643/10‐1, Deutsche Forschungsgemeinschaft, Germany.