The Core Plan is based on the science of energy density. Energy density refers to the amount of calories in a given weight of food. Foods that are considered low energy dense foods have a small amount of calories for a large volume of food (for example, vegetable soups, vegetables, and fruit). High energy dense foods provide a lot of calories for a small amount of food (for example, oils, butter, cream sauce). The Core Plan provides a "balanced diet by centering on a list of healthy foods that keep you full longer."
The purpose of the Mayo Clinic Diet is to help you lose excess weight and to find a way of eating that you can sustain for a lifetime. It focuses on changing your daily routine by adding and breaking habits that can make a difference in your weight, such as eating more fruits and vegetables, not eating while you watch TV, and moving your body for 30 minutes a day.