Obesity is when one has excess body fat. A person can be at a low weight and obese at the same time if they have more fat than muscle. One can have his or her body fat measured by a dietitian or exercise physiologist. Weight management is obtained by continuous physical activity and eating healthy foods. Diet is an extremely important part of achieving wellness.
Many people like to follow the food pyramid.
Even that is constantly changing. Diet in this sense means eating healthy. There are many diets whose purpose is to cause one to lose weight. A good majority of these are unhealthy. For example, the protein or low-carb diet consists of mainly meat and green vegetables.