Nuts are foods with a high energy density, due in part to its small water content. They also present a low saturated fat content (<7%) but a high unsaturated fat contribution (40-60%). They represent one of the richest sources of dietary fiber, which is basically of the insoluble type. The effects of nut intake on health have been widely studied. Several prospective epidemiological studies performed on large cohorts have consistently shown that regular consumption of small amounts of nuts is negatively related to the risk of cardiovascular disease and to the risk of cardiovascular or all-cause mortality. From these studies can be concluded that regular consumption of small amounts of nuts leads to a 30-50% reduction in the risk of cardiovascular disease. Additionally, intervention studies have shown a positive effect of nut intake on lipid profile with significant reductions in total and LDL cholesterol levels and small or null effects on the HDL fraction. More recently, some studies have focused on the effect of nuts on body weight. At present, no evidences support a detrimental effect of nut consumption on body weight. On the contrary some weight loss studies suggest a beneficial effect of nut intake on body weight regulation.