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Clinically Proven, Doctor Recommended

Science sets Medifast and your weight-loss success apart from the rest.

Medifast is the brand recommended by thousands of health care providers.

Medifast has a long, clinical heritage of facilitating the weight loss success stories for thousands of customers and patients. It’s through our unique meal plans that we provide you with formulated nutrition and lifelong habits for weight management.

Our story began with Dr. William Vitale. His specially formulated meal plan proved successful for his patients that, many times, needed to lose a significant amount of weight. His mission was that they do so healthily and with long-term results. His patients’ success can now be yours.

Medifast is safe and effective

Medifast has been used by doctors and physicians for many years. It’s only been within the past decade that Medifast was formulated to be available to you without a doctor’s supervision. Medifast is safe and effective to do on your own whether you want to lose 15 or 120 or more pounds.

Medifast Nutrition and How It Works to Make You Lose Weight

Medifast weight loss meals are nutrient-dense and fortified with 24 vitamins and minerals, so you can lose pounds and inches without losing out on nutrition. Each meal has essentially the same nutritional profile, and has been designed to have enough low-fat protein and healthy fiber to help you feel full and satisfied, without the between-meal hunger that can sabotage a weight loss plan.

The Key?

After a few days on either Medifast weight loss plan, your body will start to burn fat so you can lose weight while preserving muscle tissue.

Scientific Advisors to Ensure Continued Effectiveness

Medifast employs a Scientific Advisory Board that’s composed of a distinguished panel of scientists and doctors. Their role is to review the effectiveness, safety, and nutritional benefits of Medifast’s products and programs. The board also helps develop new meals and supplements and investigates alternate weight-loss approaches for those with special medical or nutritional needs, such as patients with heart disease or those who follow a vegetarian diet. We have options for just about anyone.

Clinical studies prove time and again that Medifast works.

  • Clinically proven safe and effective by researchers at major university teaching hospitals.
  • Studies published in major medical journals have proven meal replacements to be an effective method of weight loss and weight maintenance.


Clinical studies prove time and again that Medifast works. Read the research here.*

Study 1

Nutrition Journal. Davis, et al.

This study compared the Medifast Program to a conventional USDA food-based diet of equal calories. After 16 weeks of weight loss, the results suggested that the Medifast program is a more effective strategy for producing robust initial weight loss and for achieving improvements in a number of health-related parameters during weight maintenance.

Study 2

International Journal of Obesity. Shikany, et al.

This study compared the Medifast Program to a conventional food-based diet of equal calories. Medifast resulted in significantly greater reductions in body weight and fat compared with a food-based diet for 1 year after randomization.

* All studies based on the Medifast GO™ Plan (formerly the Medifast 5 & 1 Plan®).