Dean Ornish Diet

What it is: A vegetarian or mostly vegetarian developed to reverse heart disease, which has been very effective in allowing those with heart problems to shed pounds.

How it works: Rather than tracking how much you are eating, practitioners of this diet avoid specific foods. This diet is intended as a long-term lifestyle.

What you do: Practitioners eat mostly whole grains, vegetables, fruits and legumes and avoid red meat, sugar, refined grains, alcohol, nuts and avocados. Some fish and skinless chicken breast is also allowed in moderation, if a vegetarian diet is not preferred.

Benefits: According to Dean Ornish, this diet allows you to consume more food with a lower percentage of calories from fat. There is no need to count calories or measure portions. This diet can lower cholesterol and help prevent chronic disease.

The downside: The extensive food restrictions of this diet are not appealing to everyone.