by Scheinberg D

About Medifast

People on the Medifast diet eat prepackaged Medifast meal replacements 5 times a day to lose weight. This costs about $300 each month. Medifast says most people lose 2 to 5 pounds each week.

How Might Medifast Work?

Medifast believes that eating low calorie, low fat, and low glycemic index foods makes the body use its fat storage for fuel. The program gives you meals and someone on their staff to support you. It says that the protein and carbohydrates in their food will keep up muscle mass while you lose fat.

What Do I Need to Do?

The program has 3 phases: 5 & 1 plan, transition, and maintenance.

The core part of Medifast is the 5 & 1 plan. You will use this until you get to the weight you want to be at. You will eat 5 meal replacements each day. There are over 70 to choose from, such as soups, shakes, and bars. You will also eat one meal of lean meat and nonstarchy veggies each day.

All of these products have vitamins and minerals to help you meet your needs. This would be hard to meet without the products. Medifast only gives you around 800 to 1,000 calories per day. All meals are low-fat, low-glycemic, and many are gluten-free. You cannot eat starches, fruits, and dairy during the weight loss phase. You can never eat greasy, fried, or sugary foods when you are on the Medifast program. You make the daily “lean and green” meal. This is 5 to 7 ounces of lean meat, fish, or poultry, plus 1 to 2 cups of veggies or salad. There are choices for vegetarians. Meals with high protein need to be eaten every 2 to 3 hours, so you will not feel too hungry.

The first step is to pick your program, such as:

  • Women
  • Men
  • Vegetarians
  • Women who are nursing
  • Seniors
  • Teens
  • People with gout
  • People with diabetes
  • People who had bariatric surgery
  • People taking blood thinners
  • People who do not eat soy products

Then you pick a support system:

  • Online support group
  • Online health coach
  • In the Medifast center with your own coach
  • Your doctor

The next step is to order meals. Then, you eat 6 times a day (5 of the Medifast meals) until you get to the weight you want to be at.

After you lose weight, you start thetransition phase. This slowly lets you start having foods that were missing in the weight-loss phase, such as fruit, starches, and dairy. It also raises your calorie intake. Over many weeks, there is a shift away from the packaged meals. How long this phase takes depends on how much weight you lost. People who lost less than 50 pounds will spend 8 weeks in this phase. People who lost 50 to 100 pounds will spend 12 weeks. This lets the body get used to these foods again.

The final phase ismaintenance. You can now eat healthy, balanced foods with some Medifast meals. You will be told how many calories you need to stay at your weight as well. You will need to keep eating many of the meal replacement products each day in this phase.

Medifast says that people on the program should workout often, mainly during the transition and maintenance phases.


Medifast also has:

  • A free online meal planner, weight-loss tracker, and support
  • Dietitians who can talk to you by phone or online
  • One on one counseling with health coaches
  • Some states have weight-loss offices for in-person support

What Does the Research Say?

Research suggests that going on a meal replacement diet can be a safe and useful way to lose weight. That is if you can stick to the diet. Studies have also found that these diets can help people keep the weight off. This lowers their risk of health problems due to weight. Also, one study found that women on a meal replacement diet were more likely to meet their vitamin and mineral needs than those on a food-based, calorie-restricted diet. A study sponsored by Medifast also found that it may aid fat loss, not muscle loss.

There is also some research that suggests that diets like this one may help people with diabetes who need to lose weight. A study at Johns Hopkins University found that a diet of portion-controlled meal replacements helped obese people with diabetes lose weight and keep it off for 1 year. It can also help people with diabetes control their blood glucose.

No research supports the idea that you should not eat some healthy foods, such as whole grains, low-fat dairy products, and fresh fruit to lose weight. These foods have lots of nutrients. Fruits and whole grains are also high in fiber. Medifast does have these foods in the transition and maintenance phases of the program, but not in the 5 & 1 plan. Also the program's meals are nutrient-fortified, so you are still getting some vitamins from them.

Are There Any Concerns?

Talk to your doctor before you start this program. It is very low in calories. Some people should not try it, such as women who are pregnant or nursing and very active people. Medifast also warns of problems like constipation, lightheadedness, fatigue, feeling cold, and dry skin or hair.

Also, any diet that cuts out major healthy food groups should be used only if there are no other choices. This one may be a good idea for people who have failed on a healthy meal plan and are going to think about having surgery.

Bottom Line

Medifast is not for everyone. But it may help some people lose weight. Meet with a dietitian to help you talk about what type of diet is best for you.


Eat Right—Academy of Nutrition and Dietetics 

National Institute of Diabetes and Digestive and Kidney Diseases 


Dietitians of Canada 

Health Canada 


Davis LM, Coleman C, et al. Efficacy of a meal replacement diet plan compared to a food-based diet plan after a period of weight loss and weight maintenance: a randomized controlled trial. Nutr J. 2010; 9:11.

Diets for weight loss. EBSCO Nursing Reference Center website. Available at: . Updated June 16, 2017. Accessed March 14, 2019.

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