Diet and lifestyle are major modifiable determinants of inflammation, hypertension, atherogenic dyslipidemia, glucose metabolism and central obesity and should be targeted for the prevention and treatment of the metabolic syndrome. As insulin resistance, raised fasting and postprandial insulin levels, impaired carbohydrate tolerance and, ultimately, diabetes (all components of the metabolic syndrome) have been related to increased cardiovascular risk, in this report we review the potential role that individual nutrients, foods/food groups, and dietary patterns play in insulin sensitivity and secretion in the management of metabolic syndrome. We also discuss the effect of diet alone on inflammation and the homeostatic control of glucose, regardless of the effect of exercise and weight loss.