4:3 intermittent fasting helps people shed more weight than daily calorie counting — and it may be easier to stick with

If you’ve ever felt worn down by the relentless grind of calorie counting, science might finally have your back. A year-long study suggests that cutting back just three days a week—rather than tracking every bite, every day—could be a more sustainable and effective weight loss approach.

The trial, published in Annals of Internal Medicine, examined two dieting strategies in 165 overweight and obese adults: one group used traditional daily calorie restriction, while the other adopted a 4:3 intermittent fasting plan. That meant four days of regular eating and three non-consecutive “fast” days each week.

On fasting days, participants consumed only 20% of their normal calorie intake—around 400–600kcal for women and 500–700kcal for men. The remaining four days? Eat freely (though nutritious options were encouraged).

After 12 months, the intermittent fasters had lost an average of 7.6% of their body weight. Those counting calories every day saw a more modest 5% drop. The fasting group also saw slightly better outcomes in blood pressure, cholesterol, and glucose levels.

“This isn’t a miracle fix,” said Dr Adam Collins, a nutrition scientist at the University of Surrey not involved in the study. “They just ended up in a bigger calorie deficit. But that’s exactly the point—this method might help people do that without the daily mental burden.”

Lead researcher Prof Victoria Catenacci and co-author Dr Danielle Ostendorf say that people should pick a plan that fits their lifestyle. But they now consider 4:3 intermittent fasting an evidence-backed option for long-term weight management.

Interestingly, the study hints that even on their ‘normal’ days, fasters might have unintentionally eaten less, reinforcing the idea that intermittent strategies can reshape habits without feeling like punishment.

The takeaway? You don’t need to count every calorie to lose weight effectively—just three days a week might be enough.