It has long been established that dietary fats play a significant role in both the prevention and progression of chronic disease. Hypertension, obesity, and insulin resistance are three recognized risk factors for the development of cardiovascular disease and are largely influenced by dietary fat intake. Saturated fat intake is well known to promote the development of chronic disease. Monounsaturated fats are considered to be beneficial, whereas the role that polyunsaturated fats play in health and disease has become increasingly controversial. Polyunsaturated fats are generally thought to be beneficial for human health, however the controversy relates to whether these are rich in omega-6 or omega- 3 fatty acids, and the ratio of these fatty acids. Studies have shown that these fats can exert both positive and negative effects on weight gain, blood pressure, and glucose metabolism. Recent studies indicate that dietary fat intake can affect not only the health of the adult, but that fats may also play an important role during fetal development. This review examines the role that saturated, monounsaturated, and polyunsaturated fats play in the onset, progression, and prevention of hypertension, obesity, and insulin resistance in animal models and human studies. More specifically, we have addressed the role of dietary fats during fetal development and in the health of adults and children.