GM Diet MagicPlain-language guides to the 7-day GM diet, with honest answers about what it can and cannot do.
Food and tools
General information only, not medical advice. Talk to a doctor or registered dietitian before starting any weight-loss plan. Medical disclaimer.
How does the GM diet work?
The real reasons the scale moves during the 7-day GM diet, what each day does, and the claims that do not hold up.
Short answer: the GM diet works by creating a large calorie deficit and cutting carbohydrate for most of the week. Your body uses its stored carbohydrate (glycogen), which is held with water, so the scale drops quickly. Much of that early loss is water and tends to return when you eat normally.
How the GM diet works
The GM diet works mainly by cutting calories and carbohydrate sharply for most of the week. Each day allows only certain food groups, which limits how much you can eat without counting anything.
- A large calorie deficit. Days 1 to 4 are built on fruit, vegetables, bananas and milk, which are low in energy and fat. Most people eat far less than usual.
- Very little carbohydrate from grains. Bread, rice and other grains are left out until day 7, so total carbohydrate drops.
- Lots of water-rich food. Fruit, vegetables and soup are filling for few calories, which makes the restriction easier to tolerate.
Why the scale drops so fast
When you eat little carbohydrate, your body uses its stored carbohydrate, called glycogen, from the liver and muscles. Glycogen is stored with water, roughly three grams of water for every gram of glycogen, so using it up releases water as well. That is why the scale can drop quickly in the first days.
Much of that early loss is water and stored carbohydrate rather than body fat. When you return to normal meals, glycogen and its water are restored, and some of the weight comes back.
What each day does
| Day | Foods | Effect |
|---|---|---|
| 1 | Fruit only | Very low calories and protein; mostly water and natural sugar |
| 2 | Vegetables | Even lower calories, plenty of fibre |
| 3 | Fruit and vegetables | Low calories; carbohydrate stores keep falling |
| 4 | Bananas and milk | More energy and some protein, calcium and potassium |
| 5 | Protein and tomatoes | First substantial protein of the week |
| 6 | Protein and vegetables | Protein with fibre-rich vegetables |
| 7 | Brown rice, vegetables and juice | Carbohydrate returns; glycogen starts to refill |
What the GM diet does not do
- It does not rely on “negative-calorie” foods. No food uses more energy to digest than it provides. Cabbage soup and celery are simply very low in calories.
- It does not detox the body. Your liver and kidneys do that; there is no evidence that this plan improves it.
- Wonder soup does not burn fat. It is filling and low in calories, which helps with hunger, but no single food burns fat.
- There is no evidence General Motors created it. The plan’s origin is unknown, and no clinical study has tested it.
What happens after day 7
Because much of the early loss is water, some weight usually returns within days of eating normally. Keeping any fat loss depends on what you eat in the following weeks: balanced meals, regular protein, vegetables and whole grains, and fewer sugary and processed foods. See what to eat after the GM diet.
Read next
Frequently asked questions
Why do you lose weight so fast on the GM diet?
Mostly because of a large calorie deficit and low carbohydrate intake. Using up stored glycogen releases the water held with it, so early losses are largely water.
Is the weight loss on the GM diet fat or water?
Both, but much of the first few days’ loss is water and stored carbohydrate. True fat loss over one week is far smaller than the number on the scale.
Do negative-calorie foods make the GM diet work?
No. No food uses more energy to digest than it contains. Fruit, vegetables and cabbage soup work because they are very low in calories and filling.
Does the GM diet speed up metabolism?
There is no evidence that it does. Very low-calorie eating can make you feel tired, and it does not raise your metabolic rate.
Before you start
The GM diet is very low in calories and protein on several days, and no clinical study has tested it. Do not follow it if you are pregnant, breastfeeding, under 18, have diabetes, kidney disease, heart disease, low blood pressure or a history of disordered eating, or take regular medication, unless a doctor has agreed. Stop and eat normally if you feel faint, dizzy, confused or unwell.