GM diet side effects: what to expect and when to stop
The common side effects of the 7-day GM diet, why they happen, and the warning signs that mean you should stop.
Short answer: tiredness, hunger, headaches and irritability are common, especially on days 1 to 4 when the plan is lowest in protein and energy. Stop and eat a normal meal if you feel faint, dizzy, confused, shaky or have a racing heart.
Common side effects
- Hunger and cravings, mainly on days 1 to 3, because the plan is low in protein and fat, which help you feel full.
- Tiredness and low energy, because total calories are very low for most of the week.
- Headaches, which can come from low energy intake, cutting caffeine suddenly or not drinking enough.
- Irritability and poor concentration, especially on busy work days.
- Bloating or wind on vegetable-heavy days and from large amounts of cabbage soup.
When they usually appear
Many people find day 1 and day 2 the hardest. Energy often improves a little on day 4 and day 5 as bananas, milk and protein return.
How to reduce them
- Eat regularly instead of skipping meals, and keep wonder soup ready.
- Drink water through the day.
- Cut back on caffeine gradually in the days before you start.
- Keep exercise light, as explained in our exercise guide.
When to stop
Stop the plan and eat a normal meal if you feel faint, dizzy, shaky, confused or very weak, or notice a racing or irregular heartbeat. Seek medical help if symptoms do not settle quickly.
Frequently asked questions
Is it normal to feel tired on the GM diet?
Yes. Tiredness is common because the plan is very low in calories and protein, especially on days 1 to 4.
Why do I get headaches on the GM diet?
Low energy intake, cutting caffeine suddenly and not drinking enough are common causes. Eat regularly and drink water through the day.
When should I stop the GM diet?
Stop if you feel faint, dizzy, shaky, confused, very weak or have a racing heart, and seek medical help if symptoms continue.
A note on safety
This is general information, not medical advice. Speak to a doctor or registered dietitian before starting any restrictive diet, especially if you have a health condition or take medication. See our medical disclaimer.
Sources
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.