I believe nutrition does play a significant role in health promotion and disease prevention. Eating right is part of being healthy and maintaining the body. With all of the products available it is easy to eat in very unhealthy ways that weren't available to people a few centuries ago. Nutrition is a vital part of remaining healthy throughout life.
When a person has a proper diet, he or she is much less likely to develop heart diseases and other problems related to food. For example, if a person eats McDonalds and other fast food too often, he or she is at greater risk of developing heart disease. In addition to this, a person who eats too much sugar can eventually lead to diabetes and other problems. Nutrition and diet has to do with the body's ability to fight off certain diseases.
Proper nutrition is about eating a well balanced diet composed of whole, unprocessed foods, organic, non-genetically modified foods. Such a diet can help a person maintain a healthy body weight as well as get the vitamins and minerals they need. This will lead to a stronger immune system, and will help stave off preventable diseases like heart attacks, diabetes, and even cancer.
Its going to play a huge role in the way your body stays healthy and also in keeping it healthy. If you look at 3rd world countries with famine, disease runs crazy through those parts. I know its due to lack of medicine,but keeping the common cold away could be as simple as staying healthy.