The Atkins diet is an extremely popular low-carb diet. In this diet it is accepted to eat high fat foods such as bacon, but high carbohydrate foods and refined sugars are completely out. The atkins suggests that the body will enter a state called ketosis when it runs out of carbohydrates to burn. In ketosis the body switches from burning glucose to stored fat.

When this diet first became popular it was controversial because it was generally accepted that high fat foods were the major contributor to weight gain. The Atkins diet allowed the consumption of meats at the expense of carbohydrates such as pasta and bread. Some scientists believed that the atkins dieters initial losses were due to the loss of water weight and after that the losses were simlilar to other types of diets. After a period of a year low carb diets and low fat diets had similar statistics of weight loss. They were both equally difficult for dieters to stick to.