Nutrition and the therapeutic use of foods are a cornerstone of naturopathic medicine. The naturopathic approach to diet and nutrition has been validated in many scientifically based professional journals on nutrition and dietary sciences. Many medical conditions can be treated as effectively with foods and nutritional supplements as with other means, with fewer complications and side effects. While most medical doctors receive fewer than 20 classroom hours in clinical nutrition, naturopathic doctors receive more than 140 hours. Naturopathic doctors understand that diet is the basis for health. Adopting a healthy diet is often the first step towards correcting health problems. Naturopathic doctors may use specific individual diets, detoxification, fasting, and nutritional supplements with their patients.