Your diet is made up of what you eat. A healthy diet
There are many different types of diets. Some, like a vegetarian diet, don't include meats. Others, like the Mediterranean diet, describe a traditional way of eating of a specific region. And there are diets for people with certain health problems, such as diabetes.
Many people follow specific diets to lose weight. Some of these diets are fad or crash diets that severely restrict calories or the types of food you are allowed to eat. These diets rarely lead to permanent weight loss and often don't provide all of the nutrients your body needs. To lose weight, you need to use more calories than you eat. Portion control is the key. When trying to lose weight, you can still eat your favorite foods -- as long as you pay attention to the total number of calories that you eat.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
References and abstracts from MEDLINE/PubMed (National Library of Medicine)