Diet and nutrition play a crucial role in maintaining good health. Many of the noncommunicable diseases are influenced by faulty diets. The noncommunicable diseases include cardiovascular diseases, cancer, diabetes, and respiratory diseases. To make matters worse, if there is an association between an unhealthy diet and environmental pollution, it increases morbidity and mortality. This chapter discusses the role of diet in disease prevention with an emphasis on foods, which can prove to be beneficial to the human body. The active chemical compounds present in the food are discussed for better understanding. Educating the public regarding the importance of intake of healthy food and a better lifestyle may help combat various noncommunicable life-threatening diseases.