Excessive consumption of fat and sugar is associated with development of diet related diseases. While there are multiple factors involved with overconsumption of sweet and fatty foods, the taste system is responsible for identifying sugars and fats in foods, and in this way inform consumption of potential foods. Published research linking sweet taste and sugar consumption is limited and conflicting with one recent dietary intervention supporting a link between sweet taste and sugar consumption.

The serum total and LDL cholesterol levels of long-term vegans tend to be very low. The characteristically low ratio of saturated to unsaturated fat in vegan diets, and the absence of cholesterol in such diets, clearly contribute to this effect. But there is reason to suspect that the quantity and composition of dietary protein also play a role in this regard. Vegan diets of moderate protein intake tend to be relatively low in certain essential amino acids, and as a result may increase hepatic activity of the kinase GCN2, which functions as a gauge of amino acid status.