5 Reasons To Skip The GM Diet Plan, According To Science.

gm diet plan

Welcome to Diet Review series, where look at the evidence behind different diets. We’ve previously covered the dairy-free diet, the hcg diet, the 3-day military diet, and today we’re targeting the GM diet plan. Let’s get into it.

The GM diet plan promises to cleanse your body of toxins and lose quite a bit of weight in just 7 days!

Yes, if you’ve never heard of the GM diet plan, it is exactly what you think: General Motors is apparently now offering diet plans. Because if you can trust a car company with anything, it’s solid nutrition advice, right?

I had never heard of the GM diet plan before, but a quick Google search revealed that it has steadily been making the rounds on dieting websites and message boards in recent years. People tout the diet as a “proven” and “effective” way to lose weight; in fact, the diet plan promises that you can lose 16-17 pounds in just one week!

The GM diet plan was rumored to be a product of General Motors as a method to help employees and their families get healthy. It was also allegedly created with input from the Food and Drug Administration, the US Department of Agriculture, and John Hopkins University.

If that all sounds too bizarre to possibly be true, that’s probably because it is. New York Times writer Roger Cohen penned a piece about the diet and reached out to a GM spokesman, confirming that it is a myth.

That’s right, the GM diet plan did not come from the GM car company, and I would be willing to bet it probably doesn’t have ties to the FDA, the USDA, or John Hopkins either.

How The GM diet plan works

The GM diet plan is said to work because:

  • the foods you eat (supposedly) burn more calories than the calories they contain.
  • it (also supposedly) puts your body through a “detoxification” process due to the high water content of foods consumed and the rapid weight loss it promises.

The diet is designed to be followed over one week with specific guidelines laid out for each day. Here’s the basic premises of the diet:

Day 1: Eat any fruit you want this day, except for bananas. You’ll only be eating fruit on this day. Apparently melons are especially recommended, for whatever reason.

Day 2: On this day, you’ll only be eating vegetables. Raw or cooked, it doesn’t matter. One website even suggests having a baked potato for breakfast, because why not?

Day 3: Avoid bananas and potatoes, but otherwise you can have whatever fruits and veggies you want for the third day.

Day 4: Here’s where it starts to get a little more interesting. For the fourth day of this diet, you’ll only be eating bananas, milk, and soup. Up to eight bananas and three glasses of milk, to be specific, plus a special GM diet plan soup that consists of vegetables, water, and chicken soup stock. Yum!

Day 5: Now it’s all about beef and tomatoes. Yes, six whole tomatoes and two 10 ounce portions of beef. You’re also supposed to up your water intake by a quart to get rid of all that uric acid produced from essentially eating almost seven servings of red meat.

Day 6: This is basically a repeat of day 5, but skip the tomatoes and use whatever vegetables you want. Still keep that 20 ounces of red meat, though, because more is always better!

Day 7: The last day of the GM diet plan consists of brown rice, fruit juice, and unlimited vegetables. You’re also supposed to be 10-17 pounds lighter at this point.

As for side effects you might experience throughout the seven days, websites promoting the GM diet plan note that you might feel muscle weakness, dehydration, increased thirst, and headaches.

But just ignore all of those symptoms—it’s totally worth it and not dangerous at all because, hey, you’re losing weight!

So with all of that in mind…

Let’s look at the science (or lack thereof) behind the famous GM diet plan

1. There’s no evidence to support the GM Diet Plan.

GM diet plan
One of the (many) problems with this diet is that there is no real evidence behind it.

Yes, fruits and vegetables are good for you and good for weight loss. They’re packed with fiber but low in calories, meaning they’re great for promoting satiety if you’re on a diet.

That’s pretty much where the science supporting the diet stops, however. In fact, it’s safe to say that consuming nothing but fruits and vegetables for the first three days of this diet is neither healthy nor advisable.

Additionally, a hefty chunk of the GM diet plan’s foundation rests on the concept of “negative calorie foods,” or foods that burn more energy digesting than they actually contain. Unfortunately, the myth of negative calorie foods has been repeatedly debunked.

According to the Academy of Nutrition and Dietetics:

As enticing as it seems to eat foods that require more energy to chew, digest and absorb than they actually contain, there is no research to support this claim. Although foods such as celery, lettuce and cucumbers may have negligible calories, make no mistake, they still count towards a day’s worth of calories.

And as for the magic fat-burning food combinations, like bananas, milk, and soup? It seems that they’ve just been arbitrarily chosen with zero evidence to back up their claims, likely by someone with next to no nutrition knowledge (or taste buds…ick).

2. The GM Diet Plan is missing out on some important nutrients.

GM diet plan

The first three days of the GM diet plan is filled with fruits and vegetables, which sounds like it should be super healthy…except you’re missing out on a good portion of the vitamins, minerals, and nutrients your body needs to function.

First of all, let’s talk about protein. Fruits and vegetables are great, but they don’t contain nearly enough of the protein we need to power through the day.

Without adequate protein intake, you’re more likely to feel hungry and faint with a weakened immune system, hair loss, muscle depletion, and edema.

Ensuring adequate protein intake can also help determine body composition and promote weight loss, too.

  • A recent study by Beasley et. al conducted a cross-sectional study looking at body composition and protein intake. They found that older adults who were meeting the RDA for protein intake were more likely to have a higher percentage of fat-free mass than those who were eating less than 0.8 g/kg protein.
  • Another study in the Journal of Behavioral Medicine analyzed some of the key behaviors practiced by successful weight loss maintainers. Among them: regular consumption of vegetables, eating breakfast, and increased protein consumption.

Besides protein, days 1-3 of the GM diet plan are notably lacking in vitamin B12, calcium, iron, and fat. Sorry, but loading up on red meat doesn’t make up for completely nixing these nutrients from your diet for a few days in a row.

Simply put, skimping on your nutrition for a few days and then attempting to make up for it in a single shot just doesn’t work. For water-soluble vitamins like B-12, excess will just be excreted through the urine. For other nutrients, there are established levels for tolerable upper intake because toxicity can be dangerous.

Instead of totally neglecting certain nutrients for a few days and then overdoing it the next day, why not just follow a balanced and healthy diet that meets your needs all week long?

3. The GM Diet Plan goes overboard with encouraging excessive amounts.

GM diet plan

The GM diet plan is probably the only diet that actually encourages people to consume 20 ounces of red meat two days in a row. Wonder why?

The American Heart Association states that chicken, fish, and beans should be chosen over red meat due to the lower amounts of cholesterol and saturated fat. They also note that red meat in moderation is okay, but one portion should be around three ounces.

Enter the GM diet plan, which recommends eating a whopping 40 ounces of red meat (13 servings!) in just two days.

This advice is totally contrary to the massive amounts of evidence that support actually cutting red meat consumption to reduce the risk of cancer, heart disease, and mortality.

  • In 2015, the World Health Organization released a review classifying red meat as “probably carcinogenic to humans” and noted that there was strong evidence supporting a carcinogenic effect with the consumption of red meat. This was observed mainly for colorectal cancer as well as pancreatic and prostate cancer.
  • A study published in the International Journal of Cardiology found that women who consumed at least 50 grams of processed red meat per day had a 78% higher risk of heart failure compared to women consuming less than 25 grams per day.
  • A prospective study by Pan et. al found that each additional 3 ounce serving of unprocessed red meat consumed daily increased the risk of mortality by 13%, and 20% if the serving was processed.

Red meat isn’t the only thing encouraged in excess on the GM diet plan. Fruits and veggies are a heavy component of the diet, and not in moderation, either.

I’ve mentioned already about how fruits and vegetables should absolutely be a part of any healthy diet, but eight bananas in a day is a tad excessive. And including only fruits and vegetables in your diet means you’ll be missing out on several crucial nutrients (see #2).

The important takeaway here is that moderation is absolutely essential to a healthy diet and lifestyle. Unfortunately, moderation is not a strong suit of the GM diet plan.

4. That rapid weight loss you might get on the GM Diet Plan is not sustainable.

GM diet planWill you see some weight loss on the GM diet plan? Probably—after all, you are seriously cutting your calories to a point where weight loss is almost guaranteed.

How much weight will you lose? It depends on where you’re starting from, plus a variety of other factors, but you probably won’t be seeing the 10-17 pound weight loss advertised by the GM diet plan.

What you will almost certainly see, however, is some water weight loss.

Basically, anytime you significantly cut calories, your body starts to look for other sources of energy. Glycogen, stored mostly in the liver and muscles, is broken down and used to fuel the body. Because glycogen holds onto a lot of water, you’ll often see the scale drop as those glycogen stores are depleted.

Unfortunately, this kind of weight loss is only temporary. After you resume a normal diet, your glycogen stores are restored and you’re back to square one.

5. Your body is not “detoxing” on the GM Diet Plan.

GM diet planSome in favor of the GM diet plan claim that the diet works so well because it’s clearing out all those toxins from your body. Not because you’re severely restricting your calories and forcing yourself to eat some vile food combinations that would make anyone lose their appetite.

The good news is that you don’t have to subject yourself to eating only beef and tomatoes in order to “detoxify” your body. In fact, a healthy diet and lifestyle can support your body in detoxifying itself just fine! Detox diet plans don’t help your body detox.

  • Our skin excretes sweat and bacteria through the pores.
  • Our liver detoxifies and removes harmful substances from our body.
  • Our kidneys filter the blood and remove waste through the urine.
  • Our intestines digest and absorb nutrients from our food, then excrete waste products.
  • Our lungs expel carbon dioxide with each breath.

Instead of following crazy fad diets in pursuit of detoxification, you can easily support your body’s own natural detoxification process.

Drink plenty of water, include lots of fruits and vegetables in you diet, and make sure you’re getting enough fiber. It’s much easier and much more effective than any detox diet out there.

gm diet plan science

GM Diet Plan Report Card

Sustainability: F
This diet is designed to be followed for a week, though proponents claim that it can be repeated several times to achieve weight loss goals. Following this diet for seven days is one thing, but any longer than that and it’s likely to lead to serious adverse effects on your health.

Effectiveness: D
If you’re actually willing to subject yourself to the GM diet plan, you will probably see some weight loss. How long that weight loss lasts, however, is another story.

Nutrition: D

The one good thing about this plan is its emphasis on fruits and veggies. Without other nutrients to complement this, however, this diet falls flat when it comes to nutrition.

Final Grade: D-

Really, there’s no need to try out these crazy fad diets if you’re trying to lose weight. Faster isn’t always better, especially when it comes to your health. Instead, take it slow, build healthy habits, and enjoy the journey to good health. And please, don’t take nutrition advice from a car company.

Have you heard of the GM diet plan? Have you tried it or do you know someone who has? Let’s hear your thoughts below!



Beasley JM, Deierlein AL, Morland KB, Granieri EC, Spark A. Is Meeting the Recommended Dietary Allowance (RDA) for Protein Related to Body Composition among Older Adults?: Results from the Cardiovascular Health of Seniors and Built Environment Study. J Nutr Health Aging. 2016;20(8):790-796.

Kaluza J, Åkesson A, Wolk A. Long-term processed and unprocessed red meat consumption and risk of heart failure: A prospective cohort study of women. Int J Cardiol. 2015;193:42-6.

Pan A, Sun Q, Bernstein AM, et al. Red meat consumption and mortality: results from 2 prospective cohort studies. Arch Intern Med. 2012;172(7):555-63.

Santos I, Vieira PN, Silva MN, Sardinha LB, Teixeira PJ. Weight control behaviors of highly successful weight loss maintainers: the Portuguese Weight Control Registry. J Behav Med. 2016.

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  1. I tried the GM diet. I started at 78.5 kg and finished at 73.5 kg. I immediately gained 1.5 kg upon resuming a normal diet, however, that means I have a sustained weight loss of 3 kg. I kept this off despite having a few binge days and I seem to be able to eat more now without gaining weight. Additionally, I healed an anal fissure, reversed my constipation and am now more able to tolerate foods that previously gave me terrible symptoms. I seriously doubt that 3 days without meat damages the health. I also doubt that you can get a toxic overdose of vitamins from eating fruit and vegetables for 3 days. Further, 20 ounces of meat is specified on the meat days. It does not say you have to have red meat. You can have fish or chicken instead and all of it must be low fat. 20 ounces is the upper limit, I found myself eating 10oz. Since this diet is only for 7 days, I do not think you would suffer any nutritional deficiencies. I would advise leaving 3 weeks between rounds. While doing this diet I lost a lot of inflammation around my abdomen, which I think came from foods I didn’t realise I was intolerant to. I still look better and feel better. I don’t know why this diet works, except I could guess it is somehow healthy for the digestion. I have no science to back it up, just personal experience. As a long term hypothyroid and fibromyalgia sufferer, I can only report it as the best healing and weight loss diet I have tried. Just eating healthily is easier to focus on in between the rounds. I certainly found it very useful and uplifting.