What Is the GM Diet?

The GM Diet, formally the General Motors Diet, is a seven-day diet plan that promises to help you lose an eyebrow-raising number of pounds—up to 15—in just one week. One GM Diet website even purports that you can lose 10 to 15 pounds in one week without exercising at all. If that’s not enough of a red flag to keep you away from the GM Diet, perhaps the rest of this guide will clarify just how strange and unnecessary the GM Diet is.

Background

Supposedly, the GM Diet was developed for employees of General Motors, Inc in the 1980s. All across the Internet, you’ll find websites that claim the GM diet was formulated in conjunction with the United States Department of Agriculture (USDA) and Food and Drug Administration (FDA) and was “field-tested” at John Hopkins University.

However, no reputable websites purport any of those claims—only sites that do not include peer-reviewed scientific studies or input from dietary experts do say those things—and in 2009, a General Motors spokesperson “concluded it’s an urban myth” in an opinion article penned by Robert Cohen in the New York Times.

If you peruse the FDA, USDA, and John Hopkins websites, you’ll find no mention of the GM diet, which is a good thing, because this so-called miracle diet isn’t backed by any science whatsoever (to see for yourself, search the PubMed database of research studies for the GM Diet). It’s also been referred to as the GM Detox Diet, which is yet another red flag, because self-imposed detoxes of any type may not be a good idea.1

If you were to give any credit to the original creators of the GM Diet (whoever they may be, as the origins of the diet remain unknown), you could at least say that back in the 1980s, not many people knew that fad diets were useless.

Anyhow, the GM Diet seems to have persisted for quite some time, as people are still posting about it on various Internet channels, including social media, blogs, and forums. Though Verywell Fit doesn’t recommend the GM Diet as a bonafide weight-loss diet or as a sustainable healthy diet, it is worth discussing, if only to debunk its falsities.

How It Works

The GM Diet is a seven-day weight loss diet plan. It involves eating specific foods on specific days, cutting out many food groups and beverages, and drinking something called “GM Wonder Soup” when you get hungry. If that sounds odd to you, it’s only going to get weirder—this section explains in full detail the oddities of this origins-unknown diet.

What to Eat

The selection of foods you get to eat on the GM Diet isn’t necessarily bad (they’re all healthful foods in their own right), but the combinations in which you’re allowed to eat them does seem strange, and can even contribute to troubling mindsets about food combining, which may lead to disordered eating habits if you follow the diet for longer than its intended seven days.

Recommended Timing

On the GM Diet, there’s no such thing as “recommended timing"—it’s mandatory. You can actually eat at whatever time of day suits you, but throughout the week, you’re only allowed to combine certain foods with each other on particular days.

Interestingly enough, the GM Diet doesn’t specify any calorie limits or food quantity limits. You’re free to eat as much as you want, although eating too much of any type of food can be a detriment to your weight loss progress.2 You may not have an issue with that on the GM Diet, though, because all of the allowed foods are relatively low-calorie. This means you can eat a higher volume of food but take in fewer calories.

When you get hungry in between meals, the GM Diet encourages you to eat “GM Wonder Soup,” a supposed weight-loss concoction made of celery, tomatoes, onions, bell peppers, and cabbage. While those ingredients aren’t at all bad for you, it’s improbable that this so-called Wonder Soup will help spur weight loss.

Modifications

If you modify the GM Diet, you technically wouldn’t be doing the GM Diet anymore. I suppose you could modify the diet to match your dietary preferences, such as if you’re on a vegan or vegetarian diet. But to be truthful, in terms of food selection, the GM Diet is rather inclusive—you can eat any kind of fruit and vegetables, potatoes, dairy products, and several protein sources—and you can choose based on your preferences.

The diet does leave out grains and healthy fats, but to add those back in would be to ignore the structure of the GM Diet. That’s not necessarily a bad thing, though: You do need nutrients from those food groups for optimal health.

Pros

Despite its peculiarity and unsustainable structure, the GM Diet does hold onto—if only by a thread—some notable health attributes. Here are the few:

Includes Healthy Foods

If the (unknown) creators of the GM Diet did anything right, it was that they chose a healthy group of foods. The health benefits may be near null because of the diet structure, but nonetheless, the food choices—fruit, vegetables, animal protein, milk, and vegetable-based soup—do offer health benefits in their own right.

There is limited evidence that eating fruit as snacks can aid in weight loss (as opposed to eating processed snacks),3 but eating only fruit in a day can cause blood sugar spikes and crashes without protein and fat to help slow digestion.

Doesn’t Restrict Calories

One of the very notable things about the GM Diet compared to its other fad diet counterparts is that it doesn’t emphasize calorie restriction. Perhaps the creators of the diet were smart enough to know that eating mostly fruit and vegetables does indeed lend itself to weight loss because produce has a low calorie density.

Of course, on the days you eat animal protein foods and drink milk, your calorie intake will be higher than on the fruit- or vegetable-only days. Still, there’s no emphasis on calorie counting on any of the days, which is an upside for people who struggle with keeping track of calories. It is also one less thing to worry about when the rest of the diet requires so much pondering and planning.

Emphasizes Hydration

One other great thing about the GM Diet is its focus on fluids. For one, the diet encourages you to drink a vegetable, broth-based soup, which is a great way to consume fluids and nutrients at the same time (just watch your sodium intake). But besides the soup, the GM Diet emphasizes hydration and encourages you to consume plenty of water with and in between all of your meals.