Supplementary key words twins • heritability • genetics • risk factorsCardiovascular disease (CVD) is the leading cause of death in the United States ( 1 ). Metabolic syndrome (MetS) is defi ned as the clustering of factors associated with elevated CVD risk including glucose intolerance, dyslipidaemia, hypertension, and central adiposity ( 2 ). Estimated to affect over 34% of American adults ( 1 ), MetS is designated as a secondary target of coronary heart disease risk-reduction therapy after the primary target, LDL cholesterol ( 3 ). "Cardiometabolic syndrome" is a relatively new term that describes the clustering of factors that infl uence CVD and type 2 diabetes risk ( 4 ). Cardiometabolic

Exercise has well-recognized health benefits, including reduction in risk factors for cardiovascular disease and type 2 diabetes. However, the extent to which exercise influences energy regulation and facilitates a reduction in body fat is less clear. This review summarizes published studies on the effects of different amounts of exercise on body fatness, energy intake, and food preferences in humans. The results show consistent effects of exercise on body fatness in the absence of prescribed dietary change, with a progressive loss of body fat associated with higher exercise energy expenditures in both men and women. In part, these effects appear to be mediated by a spontaneous reduction in hunger associated with participation in exercise. Insufficient data are available on whether there are changes in food preferences and taste perception that influence energy balance through macronutrient selection, so further studies in this area are needed.