Medifast Diet Review – Can It Really Help You Lose Weight?

Medifast is a meal replacement program for weight loss.

The company ships prepackaged meals and ready-to-eat snacks to your home. These are designed to help you reduce your calorie intake and lose weight.

We’ve seen that some dietary supplements can improve weight loss in moderation. For example, one of the well-known benefits of turmeric is its ability to regulate metabolic function. But what if you want to skip the supplements altogether in favor of a more all-inclusive approach?

This independent and unbiased review will explain what Medifast is and whether it really works for weight loss.

What Is Medifast?

Chocolate Shake

Medifast is a commercial weight loss program based on meal replacements. It was started in the year 1980 by a doctor named William Vitale.

Originally selling meal replacements through a network of primary physicians, the company now ships meal replacements straight to customers’ homes.

Their meals include dried shake powders, snacks and dehydrated meals that can be shipped and stored safely, then quickly prepared at home without additional ingredients.

These meals will replace most food. Depending on your plan, you will still eat one normal meal per day that is self-selected, plus possibly one self-selected snack.

Medifast dieters eat small, frequent meals — six meals in a day. Some meals are smaller snacks. They offer two plans: “Go!” and “Flex.”

The Go! plan prioritizes simplicity by providing all but one daily meal. It provides five meal replacements, as well as directions on how to choose a “lean and green” meal for dinner.

“Lean and green” refers to a low-fat protein source combined with non-starchy vegetables. This excludes potatoes, corn, carrots, squash and peas.

The Flex plan allows more personalization and variety, providing four Medifast meal replacements — a breakfast and additional shakes or bars — while allowing a self-selected “lean and green” lunch and dinner.

Medifast provides guidelines and educational materials about approved self-selected meals and snacks, including restaurant options. These encourage dieters to eat low-calorie and low-carb foods.

Dieters can continue Medifast as long as they want. On average, Medifast dieters lose weight over eight weeks.

After this, some dieters return to their self-selected diets, and some continue using Medifast products on a more limited basis to maintain weight loss.

Medifast also offers a longer-term weight maintenance program called “Thrive,” which provides a smaller number of meal replacements and offers further education for selecting high-protein, low-calorie meals.

SUMMARY:Medifast is a program that ships prepackaged, easy-to-prepare meals and meal replacement snacks to help reduce your total calorie intake.

How Does It Work?

Medifast targets weight loss by using frequent, small, low-calorie meals. This pattern of eating is designed to induce weight loss without the same degree of hunger as skipping meals or reducing the size of three daily meals.

Eating several small meals in a day instead of three large meals helps reduce calories without making you feel constantly hungry (1).

Studies show hunger is a leading reason many diets fail (2Trusted Source3Trusted Source4Trusted Source5Trusted Source).

Appetite hormones including ghrelin and glucagon-like peptide 1 (GLP-1) change in response to what and when you eat (6Trusted Source7Trusted Source).

A study of 20 men found that when the men ate breakfast as four small snacks instead of one larger meal, they experienced reduced appetite over the day.

The men eating four small snacks ate fewer calories later in the day when they were allowed to eat as much as they liked from a buffet. They also had lower levels of ghrelin and higher levels of GLP-1, indicating decreased hunger (1).

Another study of 108 men and women found that substituting a meal with a low-calorie meal replacement bar successfully reduced hunger compared to a conventional meal (Trusted Source).

By providing a controlled, low-calorie diet in a way that helps reduce hunger and cravings, Medifast helps reduce your total calorie intake.

In addition to meal replacement, Medifast also provides some education and other support for weight loss, such as encouraging diet followers to keep a food journal.

One study looked at the effects of receiving contact or support from outside the home, following 63 adults on a weight loss program with prepackaged meals.

When participants were encouraged to stick with their diet plan, they lost about 5 pounds (2.3 kg) more than those who didn’t receive encouragement (Trusted Source).

SUMMARY:Smaller, more frequent meals help control hunger and decrease the urge to cheat on your diet. Medifast also provides some diet education and counseling to help you stay motivated.

Does the Medifast Diet Plan Help You Lose Weight?

A number of studies have examined the Medifast diet, comparing it to more general, self-selected diet plans.

In a 16-week study of 90 obese adults, Medifast led to a 12% loss of body weight, compared to 7% in a control group following a self-selected, low-calorie diet.

Although Medifast dieters regained more of this weight in the 24 weeks of monitoring after the diet, their final weight at the end of 40 total weeks was lower than that of the control dieters (10Trusted Source).

This may be because they had lost more weight in the initial 16 weeks.

In another non-randomized study of 1,351 dieters using Medifast, study volunteers who stayed with the program lost an average of 26 pounds (12 kg) over one year.

In this study, only 25% of volunteers continued to the one-year mark. Volunteers who dropped out early still lost weight, but less than those who continued the diet for a full year (11Trusted Source).

In another study, 77 overweight adults lost about 10% of their body weight over 12 weeks of a Medifast diet. The diet was Medifast’s 5 & 1 meal plan, which provides five meal replacements daily, and requires dieters to provide one self-selected meal (12Trusted Source).

In a second, longer study of the Medifast 5 & 1 meal plan, dieters lost 16.5 pounds (7.5 kg) over 26 weeks, while the control group lost 8 pounds (4 kg) on a regular, self-selected weight loss diet.

A year after starting the diets, both diet groups regained some of this weight. Medifast dieters ended up 11 pounds (5 kg) lighter than when they started, compared to 4.4 pounds (2 kg) lighter for the control group.

In this study, Medifast dieters also lost more inches off the waist — 2.4 inches (6 cm) versus 1.6 inches (4 cm) for the control group (13Trusted Source).

In a study of 185 overweight dieters, another Medifast meal plan provided four Medifast meals with two self-selected meals and one snack.

Volunteers lost 24 pounds (11 kg) on average over 12 weeks. Those who continued the plan for 12 more weeks lost an additional 11 pounds (5 kg) (14Trusted Source).

Collectively, these studies demonstrate that Medifast works for weight loss, resulting in up to 2.2 pounds (1 kg) of weight loss per week. However, in each of the studies with long-term follow-up, dieters regained part of this weight after 6–12 months.

SUMMARY:Medifast dieters lose about 10% of their body weight, or 24 pounds (11 kg), on average, over about 12 weeks. Most dieters regain some, but not all of this over the following year.

Variety and Nutrition of Medifast Meal Replacements

Medifast meal replacements include bars, snacks, shakes, drinks, desserts and prepackaged meals. These are designed to provide a low-calorie, high-protein meal with relatively reduced carbs.

Medifast meals are also fortified so that the diet will provide 100% of the recommended dietary allowance for all essential vitamins and minerals.

Their meals are also fortified with dietary fiber, to increase food volume and help control appetite without adding calories.

Several of their snacks and drinks also contain added sugar to help make them palatable. The amount of added sugar is small, but enough to contribute a significant amount of sugar to your diet over several meals.


Drink options include low-calorie hot cocoa and instant cappuccino, several flavors of milk shakes and smoothies in pineapple and berry flavors.

Each is formulated to provide about 100 calories. They include supplemental protein sources like egg whites, soy protein isolate and whey protein concentrate. Protein supplies 50–75% of the calories in these products.

They also contain added sugar, accounting for 20–33% of the drinks’ calories. These products are low in fat, with usually 1–3 grams.

For example, their Dutch Chocolate Shake meal replacement contains 14 grams of protein, providing 56% of the drink’s 100 calories. It also contains 6 grams of sugar, which accounts for 24% of the calories, and the remaining 20% of calories is from fat.


Aside from drinks, one of the six daily meals on Medifast may be one of their snack bars, desserts or “cruncher” snacks, such as cheese puffs or pretzel sticks.

Medifast offers 13 varieties of snack bars. These primarily contain carbs, supplemental protein sources and sugar to improve flavor.

For example, their Cookie Dough Chewy Bar contains 110 calories with 11 grams of protein and 15 grams of carbs, including 6 grams of sugar.

Their cruncher snacks are high in protein isolates and concentrates, and low in sugar and fat. For example, their Cheese Pizza Bites contain 11 grams (44 calories) of protein and 11 grams (44 calories) of carbs, with only small amounts of sugar and fat.

Their desserts are also calorie-controlled to be about 100 calories. They naturally have a higher sugar content than other meal replacements and again contain supplemental protein.

For example, their Brownie Soft Bake contains 15 grams of carbs, 8 grams of sugar and 11 grams of protein.


Medifast produces a few varieties of pancakes and oatmeal for the first meal of the day.

The pancakes are portion-controlled to provide 110 calories, with about 14 grams of carbs, 11 grams of protein and 4 grams of sugar. The amount of protein, calories and carbs in the Medifast oatmeal are almost identical, with a little less sugar.

They also produce a selection of “hearty choices,” such as mashed potatoes and soups. These vary in their carb content, but follow the pattern of being high in protein, low in fat and around 100 calories.

Dieters can also purchase from an optional selection of larger entrées to serve as their “lean and green” meals. Each of these entrées provides about 300 calories.

For example, their Chicken Cacciatore option provides 26 grams of protein, 15 grams of carbs and 15 grams of fat.

SUMMARY:Medifast meal replacements include shakes and smoothies, oatmeal and pancakes, protein bars and snacks as well as a limited selection of entrées. Their meals follow a high-protein, low-fat, low-calorie theme.

Pros and Cons of Medifast

Like any diet, Medifast has its advantages and disadvantages.


  • Short-term weight loss: Medifast is effective for short-term weight loss — around 2.2 pounds (1 kg) on average per week of dieting.
  • Fortified meals: Meals are fortified to provide 100% or more of the recommended dietary allowance of all essential vitamins and minerals.
  • Education and support: Medifast provides education and a limited support system to help you stay motivated.
  • Easy to follow: Prepackaged foods eliminate the need for diet planning and calorie counting, making the diet simple to follow.


  • May be boring: The limited variety of types and flavors of meal replacements can lead to food cravings and cheating on the diet.
  • Dining out can be a challenge: The company provides guidelines on choosing lean proteins and non-starchy vegetables, but menu items that align with the diet may not always be available.
  • Added sugar: Several Medifast drinks and snacks add sugar to make the meals more palatable. Some of their choices provide 20% or more calories from sugar.
  • Weight regain: Most Medifast dieters will regain part of their lost weight after stopping the diet.
  • It’s expensive: A 30-day supply of meal replacements costs close to $400 USD. calculated that Medifast would cost about $12 USD per day, which includes the cost of meals not provided in the plans.

However, because you’ll be doing less grocery shopping and eating out, the cost may be less than it sounds. For example, if an average person spends about $7–9 daily on food, Medifast would cost $3–5 over their normal food budget (15).

SUMMARY:Medifast works for weight loss and is nutritionally complete, though its variety is limited and eating out can be a challenge. Most plans cost around $400 USD monthly.

How It Compares to Similar Programs

Several other meal replacement programs exist, offering a variety of meal options and prices.

A review of 45 studies of different commercial weight control programs showed similar weight loss in participants following Medifast, Nutrisystem, Jenny Craig and Optifast meal replacement diets.

The HMR (Health Management Resources) diet is another diet of prepackaged food, providing meal replacement shakes, soups and entrées. It has been shown to produce about 5% greater weight loss than the others (16Trusted Source).

In this study, SlimFast meal replacement shakes produced mixed results, with about 3% greater weight loss than control diets in some studies, and no greater weight loss than control diets in other studies.

Overall, meal replacement diets were slightly more effective than Weight Watchers, which produced 2–7% greater weight loss than control diets in several studies.

In that review, dieters using Medifast spent $424 USD per month, compared to $682 for HMR, $665 for Optifast, $570 for Jenny Craig, $280 for Nutrisystem and $70 for SlimFast.

Some diets that do not use meal replacement programs cost less. For example, in the above study, the non-meal-replacement program Weight Watchers cost $43 monthly plus the cost of food.

Other self-directed diets cost only the price of a diet book plus the cost of food (16Trusted Source).

In a similar review of many studies, all these commercial weight loss programs had dropout rates greater than 50%, and most dieters regained 50% of the weight they lost over the following one to two years (17Trusted Source).

SUMMARY:Weight loss on Medifast is similar to other meal replacement diets, such as Nutrisystem and Jenny Craig. It’s more effective, but more expensive than SlimFast or other less comprehensive commercial diets.

The Bottom Line

Medifast promotes weight loss by shipping meal replacement shakes, bars, snacks and easy-to-prepare prepackaged meals to your home.

This may be a good option for people who think they would benefit from the structure and simplicity of eating prepackaged meals for weight loss.

However, in large studies, fewer than 50% of participants were able to adhere to Medifast for 12 months or longer. Moreover, participants regained much of their lost weight over the next year.

Medifast may be effective for weight loss, but long-term weight loss requires a permanent lifestyle change.