At brunch, Anna Engler likes to eat bacon and eggs. It can even be ten strips of bacon. “I’m an absolute epicure,” says the 32-year-old Berliner. She doesn’t go without any of her favorite foods and still keeps losing weight. Since February already 14 kilos. Her method: intermittent fasting.

Instead of not eating for several days, as with classic therapeutic fasting, intermittent fasting takes a break in between. “You don’t have to count calories, you count hours. Instead of ‘Eat half’, the following applies: ‘Eat half the time’,” author and doctor Eckart von Hirschhausen sums up the principle. He lost ten kilos.

Intermittent fasting, also known as intermittent fasting, has been booming for years. Fasters report on their successes on a number of internet blogs. In Facebook groups, tens of thousands of members exchange tips and tricks and motivate themselves with before and after pictures. According to experts, the method corresponds to human nature: After all, hunters and gatherers were not provided with three meals a day.

The renunciation of the renunciation is one of the most important reasons for the boom, says the Berlin naturopath Andreas Michalsen. “It’s not a real diet, it’s just a time shift in eating, otherwise there are no regulations,” says the Charité professor and chief physician at the Immanuel Hospital, where around 1,500 fasting people are cared for every year – both therapeutic fasting people who are fasting for several days in a row eat nothing, as well as intermittent fasting.

Anna Engler fasts according to the 8:16 method: she eats eight hours a day and only has calorie-free drinks such as tea or water for the remaining 16 hours. Black coffee is also allowed. She skips breakfast. “I’ve always hated that anyway and always felt tired afterwards,” she says.

A brunch with friends is allowed. She plans her meal times flexibly. If dinner lasts into the night, the first meal on the following day is only in the afternoon. She only fasts four days a week. Otherwise, the graduate industrial engineer eats without looking at the clock. The 8:16 method is one of the most popular.

Others fast using the 5:2 method. You eat normally for five days a week and only eat up to 500 kilocalories on the other two days. “Pure” intermittent fasting is considered to be more difficult: eat one day, do without one day.

Annette Schürmann from the German Institute for Human Nutrition Potsdam-Rehbrücke explains why the pounds are disappearing. She has been researching mice for years. Their metabolism is less complex, but similar to that of humans. “Mice that eat constantly only burn carbohydrates.”

A fasting period ensures that the body switches from carbohydrate to fat metabolism. “That means that fats are really burned and the love handles are reduced,” says Schürmann. In addition, not so many toxic intermediate products accumulated in the liver. Mice again reacted sensitively to the hormone insulin, which could prevent type 2 diabetes.

It is also said that cell regeneration is stimulated. “When we fast, we give the body time to switch on its repair mode in the cells and genes,” says Michalsen, referring to autophagy, a process of waste disposal in body cells. “There is an incredible wealth of extremely impressive research on animals.” Studies have pointed to a protective effect against dementia, strokes, heart attacks and cancer.

It is not known whether this is also the case in humans. “There is a lack of large human studies. But the fact that turning the clock does something is proven,” the doctor said. He recommends that patients try intermittent fasting for themselves and find a suitable rhythm.

He has annual contact with about 500 patients who practice this. “90 percent think it’s great. you lose weight Your blood pressure improves. Ten percent isn’t good. I say to the patient: please don’t do it,” says Michalsen, who himself fasts at intervals.

On the other hand, the German Society for Nutrition (DGE) does not consider intermittent fasting to be suitable for regulating weight in the long term. According to the reasoning, there were no specific recommendations for food choices. “I don’t think it makes sense to view intermittent fasting as categorically bad,” Schürmann replies.

She recommends a compromise: “Of course you should stick to the guidelines of the DGE during the eating phases and consume enough carbohydrates, protein and little fat, lots of fruit and vegetables.”

Intermittent fasting is the best way for Anna Engler. “I don’t have a yo-yo effect like with dieting,” she says. “I feel much fitter and more flexible.” She goes jogging again and does yoga, but her stomach used to bother her. Her goal is to get back to 68 kilos and to be able to wear a size 38 dress. “There are only six kilos left,” said the 1.68-meter woman. If she reaches her goal, she wants to fast one or two days a week to keep the weight off.

Will Intermittent Fasting Displace Therapeutic Fasting? “Both approaches are complementary,” says Françoise Wilhelmi de Toledo from the board of directors of the medical association for fasting therapy