Medifast Diet


In the early 1980s, a John Hopkins University physician developed the Medifast program for surgical patients as a way to lose weight quickly prior to surgery.  Once only available through a physician’s office, the program is now available in the mainstream diet market and can be undertaken without the approval of a physician.  


Medifast claims you can lose up to 20 pounds in the first month alone by eating its pre-packaged meals.


Medifast is a meal replacement program that uses portion-controlled pre-packaged, nutritionally balanced, low-fat foods to facilitate weight loss.

Program Overview

Medifast meals are shipped directly to a participant’s home.  The meals come in individual packets that you mix with water and microwave or refrigerate, and are available in a wide variety of foods and flavors, with over 70 different menu options, including shakes, soups, stew, chili, oatmeal, scrambled eggs, fruit drinks, iced teas, hot beverages, bars, and puddings. 

One of the more popular weight loss plans is the Medifast 5 & 1 Plan, which consists of eating five pre-packaged Medifast meals and one Lean & Green meal prepared by the participant each day.  A meal is eaten every two to three hours.  Daily caloric intake is kept at between 800 and 1,000 calories a day.

The Lean & Green meal can be eaten at any time during the day.  It includes a lean meat plus a salad and/or vegetables. The lean meat can be a 7-ounces portion of chicken, turkey, fish, beef, pork, lamb, or shellfish that is grilled, baked, or poached. For the greens portion of the meal, participants select any three servings from Medifast’s approved vegetable list, such as broccoli, spinach, eggplant, or tomatoes.   

In terms of drinks, participants have their choice of any calorie-free beverage.  However, it is recommended that those on the diet drink at least 64 ounces of water each day.  Alcohol consumption is strongly discouraged while on the program.

Medifast suggests that participants stay on the 5 & 1 Plan until they have lost the desired amount of weight.  Once that is accomplished, participants are expected to transition into the Maintenance Plan.  During Transition, participants reintroduce fruits, low-fat dairy products, whole grains, and higher-carbohydrate vegetables into their diet, while giving the body time to adjust to its new level of calories and carbohydrates.  Then, it is on to the maintenance portion of the program.

Meal plans can be tailored specifically to meet the needs of men and women, young and old, as well as for people who suffer from diabetes, or require kosher, low glycemic, vegetarian or lactose-free meal plans.  

Online support through the MyMedifast weight-loss community, clinical support through the Medifast Weight Control Centers, and personal support through the Take Shape For Life Health Coach Network are available to participants.

Plan Strengths

Meal options and variety are plentiful on the Medifast program. The convenience of having the portion size already measured, and the cooking is done, is attractive to many people.  Additionally, the Medifast products have been safely and effectively used by participants and recommended by physicians for over 28 years.  

Medifast enjoys pointing out that it is one of only a few weight loss programs that have clinical trial research to back it up.  While not an extensive body of research, a handful of clinical trials by reputable institutions have found that participants on Medifast do achieve results.  In one of the most recent studies, a clinical trial published in the Journal of Nutrition (2010) suggested that participants using the Medifast 5 & 1 Plan, when compared to a self-selected isocaloric food-based diet, lost twice as much weight after completing an initial 16-week program.  According to the study, 93 percent of participants using Medifast for a 16-week period showed significant weight loss on the program, and participants demonstrated a significant increase in lean muscle mass as a percent of total weight.  Participants also lost an average of 5 inches on their waistline.    

The program incorporates the importance of daily physical activity and exercise into its program.  It stresses the need for getting at least a minimum of ten minutes of exercise each day, and while it does not provide personalized exercise plans, it does offer guidelines and recommendations for daily workouts.

Weight loss is definitely likely to occur considering how restrictive calorie intake is, and the recommendation for exercise.  Participants generally report losing anywhere from 2 to 5 pounds a week.  Severely overweight individuals (BMI greater than or equal to 30) have generally reported the greatest weight loss results.

Plan Weaknesses

Cost is likely to be a prohibitive factor for many people.  The Medifast 5 and 1 plan, for example, costs about $300 for four weeks of pre-packaged meals, and that does not include the ingredients you are expected to buy for the Lean & Green Meal.  If you were to stay on the program for the suggested 16 weeks, that is a minimum of $1,200.

Medifast also warns that participants may experience hunger, tiredness, irritability, headaches, and lightheadedness until they reach a fat-burning stage, which could take anywhere from a couple of days to a couple of weeks depending on the individual.  

The American Dietetic Association believes that the diet if undertaken should be done under the supervision of a physician given that the minimum daily calorie intake of between 800 and 1,000 calories is below the considered healthy recommendation of 1,200 calories.  


The Medifast plan has a proven record of accomplishment with clinical studies to back it up.  It does a great job of restricting caloric intake and stressing daily exercise, and for severely overweight individuals, the program has proven successful.  However, transitioning back into eating regular foods may be challenging for some people and the cost of meals may be a major financial hurdle for many.  

The information provided here is for educational or informational purposes only.  Dave DePew does not endorse any of the programs/services reviewed here. Before starting a new exercise regime or weight loss plan, talk with your doctor.

Additional Resources

Medifast official website,

Medifast diet plan review,