Scientists have found a ‘golden rule’ to make intermittent fasting diets successful

It’s a diet trend endorsed by everyone from Hollywood stars to Rishi Sunak, but intermittent fasting doesn’t work for everyone.

Now scientists claim they’ve found a way to boost its effects: by focusing on what you eat, rather than when you eat.

A group of American researchers found that the diet is only effective for weight loss and stabilizing blood sugar levels if people eat fewer calories than they need.

In other words, the amount of calories you consume is more important than the timing.

Overweight people who stuck to a 10-hour eating window from 8 a.m. to 6 p.m. and ate most of their calories in the morning lost an average of 2.3 kg (5.1 lbs) in 12 weeks.

Jennifer Aniston, Chris Pratt and Kourtney Kardashian are among the Hollywood A-listers who have jumped on the trend since it broke in the early 2010s. But despite plenty of research suggesting it works, experts are divided over its effectiveness and potential long-term health effects.

For comparison, volunteers who ate between 8 a.m. and midnight and consumed most of their calories in the evening lost 2.6 kg (5.7 lbs).

Both groups of volunteers followed an expert-recommended diet consisting of a balanced mix of fruits and vegetables, whole grains and no junk food, and low in saturated fat.

Nisa Maruthur, co-author of the study and associate professor of medicine at Johns Hopkins University, said: “What this suggests is that people who benefit from time-restricted eating, meaning they lose weight, are probably doing so because they’re eating fewer calories because their time window is shorter, and not because of anything else.”

Jennifer Anniston, Chris Pratt and Kourtney Kardashian are among the Hollywood stars who have jumped on the fasting trend since it emerged in the early 2010s.

But despite the many studies suggesting it works, experts are still divided over its effectiveness and potential long-term health effects.

Some argue that fasters typically consume a relatively large amount of food at one time, meaning they don’t restrict their calorie intake—a known way to combat obesity.

They even have warning that it may increase the risk of stroke, heart attack or premature death.

The researchers analyzed data from 41 participants, 59 years old and with an average BMI of 36.

At the start of the study, researchers assessed participants’ medical history and activity levels to estimate basal calorie needs.

Participants were given prepared meals with identical macro- and micronutrient composition.

During the study, they ate the same number of calories every day.

During the trial period, no restrictions were placed on beverages as long as they were calorie- and caffeine-free.

Participants were also allowed to drink one cup of coffee, diet soda, and alcoholic beverage per day. Outside of the designated time periods, only water was allowed.

After 12 weeks, the scientists also found that there were no real differences in fasting glucose, waist circumference, blood pressure or lipid levels.

Writing in the diary Annals of Internal MedicineAccording to the researchers: ‘Time-restricted eating did not lead to weight loss or improvement in glucose homeostasis compared to a normal eating pattern.

‘This suggests that any effects of time-restricted eating behavior on weight in previous studies may be due to a reduction in calorie intake.’