The GM diet, also known as the General Motors diet, is a plan that promises to help you lose up to 15 pounds (6.8 kg) in just one week.

Each day of the GM diet permits you to eat different foods or food groups.

Proponents of the diet claim this technique stimulates weight loss and helps burn fat faster than other diets. But does it actually work? This article looks into the GM diet and its pros and cons.

  • Overall score: 1.13
  • Weight loss: 1
  • Healthy eating: 0
  • Sustainability: 1
  • Whole body health: 0
  • Nutrition quality: 3
  • Evidence based: 1.75

BOTTOM LINE: The General Motors (GM) diet is a strict, 7-day eating pattern that’s said to promote weight loss, but it’s dangerously low in many nutrients and unsupported by research. Overall, it’s a crash diet that’s best avoided.

What is the GM diet?

It is said to have been developed with help from the US Department of Agriculture and the FDA, with extensive testing at the Johns Hopkins Research Center.

However, this claim has since been debunked as an urban myth, and the true origins of the GM diet remain unknown.

The GM diet plan is broken up into seven days, each with strict rules about which food groups you can consume.

For example, your diet on day two is limited to only vegetables, while on day five you’re instructed to eat several whole tomatoes and large portions of meat.

The diet can supposedly help you:

  • Lose up to 15 pounds (6.8 kg) in just one week
  • Get rid of toxins and impurities in your body
  • Improve your digestion
  • Enhance your body’s ability to burn fat

Proponents of the GM diet say it works because many of the foods included in the diet are low in calories, such as fruits and vegetables.

This can help promote weight loss by creating a calorie deficit, which is when you consume fewer calories than you burn throughout the day.

The plan also states that many of the foods in the diet are “negative-calorie foods,” meaning they provide fewer calories than they take to digest.

Many of the foods the diet recommends are also high in water. For this reason, proponents claim that the GM diet can enhance fat loss and help detoxify your body.

Supporters also say you may repeat the diet multiple times to achieve your long-term weight goals, recommending a gap of 5–7 days between cycles.


The origins of the GM diet remain unknown. Proponents claim it can help you detoxify, burn more fat, improve your digestion and lose up to 15 pounds (6.8 kg) in one week.

What do you eat on the diet?

The GM diet is divided into seven days, with different rules that apply to each day.

It recommends that you drink 8–12 glasses of water each day to stay hydrated throughout the diet.

Although exercise is not required for weight loss on this diet, it is optional. However, the diet recommends against exercise during the first three days.

It also allows followers to consume two to three bowls of “GM Wonder Soup” each day. It’s made with cabbage, celery, tomatoes, onions and bell peppers.

Here are the specific guidelines for each day of the GM diet:

Day one

  • Eat only fruit — any kind except bananas.
  • No maximum amount of fruit is specified.
  • The diet especially encourages followers to eat melons to increase weight loss.

Day two

  • Eat only vegetables in raw or cooked form.
  • The diet does not specify a maximum amount of vegetables.
  • Limit potatoes to breakfast only.

Day three

  • Eat only fruits and vegetables of any kind except bananas and potatoes.
  • The diet doesn’t specify a maximum amount.

Day four

  • Consume only bananas and milk.
  • You can eat up to 6 large or 8 small bananas.
  • Drink 3 glasses of milk, preferably skim.

Day five

  • Eat two 10-ounce (284-gram) portions of beef, chicken or fish.
  • In addition to the meat, you may only eat 6 whole tomatoes.
  • Vegetarians may replace meat with either brown rice or cottage cheese.
  • Increase your water intake by two glasses to flush out extra uric acid. This is a chemical product of the breakdown of purines, which are found in meat.

Day six

  • Eat only two 10-ounce (284-gram) portions of beef, chicken or fish.
  • Today’s meals may include an unlimited amount of vegetables, but no potatoes.
  • Vegetarians may replace meat with either brown rice or cottage cheese.
  • Increase your water intake by two glasses to flush out extra uric acid.

Day seven

  • Eat only brown rice, fruits, fruit juice and vegetables.
  • No maximum amount is specified for any of these foods.

Each day of the GM diet has specific rules on which foods are permitted. Fruits, vegetables, meat and milk are the main foods allowed.

Other guidelines

The GM diet provides a few other guidelines in addition to the plan outlined above.

First of all, beans are not allowed on the diet. The diet claims they are high in calories and may cause weight gain.

Coffee and green tea are permitted, but only without the addition of any sweeteners. Soda, alcohol and other calorie-filled beverages are not allowed unless specified in the diet.

Additionally, some substitutions are okay. For example, you may use cottage cheese to replace meat, and soy milk instead of regular milk.

Finally, after you’re finished the week-long plan, the GM diet advises you to consume a high-protein, low-carb diet to help maintain weight loss.


There are a few additional rules to this diet, such as avoiding beans, sweeteners and high-calorie beverages. You’re also advised to follow a low-carb, high-protein diet after the GM plan.

Sample GM diet plan menu

Here is a sample diet plan broken up into seven days:

Day one

  • Breakfast: 1 bowl of mixed berries
  • Snack: 1 pear
  • Lunch: 1 apple
  • Snack: 1 bowl of watermelon
  • Dinner: 1 orange
  • Snack: 1 bowl of cantaloupe slices

Day two

  • Breakfast: 1 bowl of boiled potatoes
  • Snack: 1 bowl of baby carrots
  • Lunch: 1 head of broccoli, cut into florets and steamed
  • Snack: 1 bowl of cherry tomatoes
  • Dinner: 5 spears of steamed asparagus with 1 bowl of arugula
  • Snack: 1/3 cucumber, sliced

Day three

  • Breakfast: 1 apple
  • Snack: 1 bowl of cherry tomatoes
  • Lunch: 1 bowl of spinach with cucumbers and tomatoes
  • Snack: 1 orange
  • Dinner: 1 bowl of kale with strawberries and avocado
  • Snack: 1 bowl of mixed berries

Day four

  • Breakfast: 2 large bananas with 1 glass of milk
  • Lunch: 2 large bananas with 1 glass of milk
  • Dinner: 2 large bananas with 1 glass of milk

Day five

  • Breakfast: 3 whole tomatoes
  • Lunch: 10-oz (284-g) steak with 1 whole tomato
  • Dinner: 10-oz (284-g) tilapia with 2 whole tomatoes

Day six

  • Breakfast: 1/2 avocado
  • Lunch: 10-oz (284-g) grilled chicken breast with asparagus and cherry tomatoes
  • Dinner: 10-oz (284-g) broiled salmon with kale and Brussels sprouts

Day seven

  • Breakfast: 1 bowl of brown rice with a side of watermelon wedges
  • Lunch: 1 bowl of brown rice with broccoli and 1 cup (237 ml) of fruit juice
  • Dinner: 1 bowl of brown rice with mixed vegetables

The GM diet is split into seven days with different food groups permitted on each day of the diet.

Benefits of the GM diet

Although no studies have examined the GM diet, there’s some research on certain aspects of it.

First of all, the plan encourages an increased intake of fruits and vegetables, which has been shown to help promote weight loss.

This is because fruits and vegetables are low in calories and can create a greater calorie deficit to increase weight loss.

In a 2015 study of more than 133,000 participants, people with the highest intake of fruits and non-starchy vegetables had the lowest risk of weight change over a four-year period (1).

In addition, the diet limits some foods and beverages that cause weight gain. Sugary beverages, for example, have been shown to contribute to weight gain (2).

Alcohol is also high in calories and may cause weight gain (3).

Despite the strict regulations about which foods are permitted on each day, the diet allows you to select your choice of meats, fruits and vegetables based on your personal preference. This could make the plan feel less restrictive.


The GM diet is somewhat flexible on the foods you can choose. It encourages you to eat more fruits and vegetables, while limiting sugar-sweetened beverages and alcohol.

Disadvantages of the GM diet

There are many disadvantages to following the GM diet, including the following:

There’s no research to support it

The biggest drawback of the GM diet is that there is no research that evaluates how well it works. Besides anecdotal evidence, there is nothing to actually back up the claims of the diet.

While the diet claims to include “negative-calorie foods” that burn more calories than they provide, there is no evidence to support this.

Though some foods do require more calories to digest than others, the foods in the GM diet still supply calories (4).

The GM diet lacks important nutrients

The diet is also not well-balanced and may lead to feelings of deprivation and hunger on some days, due to the varying amounts of macronutrients it provides.

Most days of the diet provide relatively low amounts of protein, for example.

This can actually be counterproductive, since studies show that protein can decrease appetite and enhance weight loss (5, 6).

In one six-month study of 65 participants, those on a high-protein diet lost 8.4 pounds (3.8 kg) more than those on a high-carb diet (6).

On top of these issues, the diet is lacking in many other essential nutrients. The first three days, for example, are very low in fat, vitamin B12, iron, calcium and more.

Weight loss on the GM diet may be temporary

Most of the weight lost on this diet is likely to be water weight, rather than fat.

Any time you reduce your calorie intake, your body looks for other sources of fuel. This causes your body to break down glycogen, an energy-storage molecule found in the liver and muscles.

Glycogen holds onto a lot of water, so as your glycogen stores are depleted, this loss of water can cause your weight to drop rapidly (7).

Unfortunately, this type of weight loss is only temporary. You’ll probably regain it soon after you resume your normal diet.

To achieve long-term, sustainable weight loss, pair a balanced and healthy diet with regular physical activity. Research has repeatedly shown this to be the most effective option (8, 9, 10).


There are some big downsides to the GM diet. For starters, no research backs up its claims. It also lacks important nutrients and may only lead to temporary weight loss.

Should you try the GM diet?

Many people seek out “quick fixes” to lose weight fast. Unfortunately, it’s just not possible to accomplish long-term, lasting weight loss in only one week.

Though this diet encourages you to eat fruits and vegetables while limiting sugar-sweetened beverages, its drawbacks far outweigh any potential benefits.

In short, it’s not backed by research, it lacks essential nutrients and it won’t lead to lasting weight loss.

Instead of engaging in endless cycles of yo-yo dieting and losing weight only to regain it, try incorporating a healthy diet into your everyday life.

Your weight and your health will be better for it.