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Cheat meals boost your metabolism

A big meal or a few days of overeating nudges energy expenditure and leptin up slightly, but the extra calories burned are far smaller than the extra calories eaten, so a cheat meal does not 'reset' metabolism or speed fat loss. Planned periods at maintenance calories (diet breaks) are a different, more promising idea: they may ease hunger and adherence.

What the science says

  • Overeating revs up metabolism Limited evidence

    Dirlewanger and colleagues (2000) overfed 10 lean women for 3 days. Carbohydrate overfeeding raised 24-hour energy expenditure by 7% and leptin by 28%, while fat overfeeding changed neither. The rise in expenditure covers only a small part of the surplus and lasts only while overeating continues.

  • A short break at maintenance changes metabolism in a meaningful way Limited evidence

    Peos and colleagues (2021) gave 26 resistance-trained athletes a 1-week diet break at maintenance calories. Resting energy expenditure rose by only about 200 kJ (roughly 50 kcal) a day; fat mass did not change, but hunger and irritability fell.

  • Planned maintenance blocks can improve fat loss Moderate evidence

    In the MATADOR trial (Byrne and colleagues, 2018), men with obesity who alternated 2 weeks of dieting with 2 weeks at maintenance lost more fat than continuous dieters (12.3 vs 8.0 kg) with less metabolic adaptation. These were structured weeks at maintenance, not unplanned binges, and evidence is from one trial.

What to do instead

Instead of unplanned cheat meals, budget treats into your daily calories, and if dieting for months, consider planned periods at maintenance calories.

TreatsFit into the daily or weekly calorie budget
Diet breaks1–2 weeks at maintenance after every 4–12 weeks of dieting (optional)
Calories during a diet breakEstimated maintenance, not unrestricted
ProteinKeep at about 1.6 g/kg body weight per day throughout

Who should be careful

If 'cheat' days feel like loss of control or are followed by guilt, compensatory restriction or purging, talk to a physician or psychologist; this pattern can signal disordered eating. People with diabetes, heart, kidney or thyroid conditions, anyone with a history of an eating disorder, and anyone pregnant or considering weight-loss medication should plan weight loss with a physician or registered dietitian rather than on their own.

Frequently asked questions

Does a cheat meal raise my metabolism?

Slightly at most. Three days of carbohydrate overfeeding raised 24-hour energy expenditure by 7%, far less than the extra calories eaten.

What is the difference between a cheat meal and a diet break?

A diet break is a planned period eating at maintenance calories. In the MATADOR trial, alternating 2-week diet and maintenance blocks led to more fat loss than continuous dieting.

Do diet breaks help hunger?

In a 2021 study, a 1-week diet break reduced hunger and irritability, though fat mass did not change.

Scientific references

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