Intermittent fasting, bspw. by eating nothing for 16 hours, is supposed to relieve the whole organism and also provide countable results on the scale Photo: Getty Images
From FITBOOK | 22. April 2020, 6:33 pm
Fasting for a few hours or even a whole day, then going back to eating normally: This is called interval fasting and is supposed to make you healthy and fit. But is it true?
Intermittent fasting- how does it work?
With Intermittent Fasting, there are virtually no rules about what you eat- except: breaks must be taken in between meals. Hunger phases thus become part of everyday life and the body learns to fall back on its own reserves.
„Humans were not originally accustomed to constant meals", says Hamburg-based nutritionist, internist and diabetologist Dr. med. Matthias Riedl. The reason for this is said to be the way of life of our ancestors: they had to hunt or gather their own food and did not know a constant availability of food. An alternation between fasting periods and food intake corresponds to a natural way of life and is therefore "the diet appropriate for the species", says Riedl.
Since there are no more hunger phases in our everyday lives with regular meals and lots of snacks, the body is constantly in storage mode, according to Matthias Riedl.
And not only that permanent Snacken is bad for the metabolism and the calorie balance, it can have also correctly serious consequences: Overweight and resulting illnesses such as diabetes, heart cycle illnesses or also dementia.
According to the experts, interval fasting relieves the whole organism, metabolism and organs can recover. Total calorie intake is reduced, insulin levels drop and fat is broken down more efficiently.
Different fasting methods at a glance
Intermittent fasting makes hunger phases part of everyday life again. So the body learns to fall back on its own reserves. Hours or days of fasting alternate with periods of normal eating. There are different models for this or. Methods.
16:8- Intermittent fasting for beginners
Ideal for beginners is the so-called 16:8-Fasten. Eating is allowed for eight hours a day, and the remaining 16 hours are spent without food. Advantage of this method: It can be integrated into the everyday life prima and durably. For example, if you eat your last meal at 8 p.m., you simply skip breakfast and can have a normal lunch again at 12 a.m. The eating window is then valid for eight hours, i.e. until 8 p.m. Sugar-free drinks, i.e. coffee and tea, are allowed during fasting.
Munich fitness trainer and nutritionist Hanjo Fritzsche also lives according to the 16:8 method and does without breakfast. Since he can eat normally for eight hours a day, the rest of the time he only consumes water. „In the first weeks you think a lot about food", tells Fritzsche. But if the body got used to the new rhythm, one is to feel fitter and be able to concentrate better.
TV chef Alexander Kumptner (known from "Kuchenschlacht") is also a big fan of interval fasting in the ZDF). Why it finds this Lifestyle ideal for itself and like it the 16:8-Fasten handles, it FITBOOK in the interview betrayed.
20:4- the "Warrior Diet
Clearly harder is the 20:4-Fasten, also admits under the name "Warrior Diat". The time window for the food admission is reduced thereby to four hours on the day. During the fasting period, however, one may consume vegetable juices and raw vegetables.
5:2 and 6:1- the part-time fasting
Another example is 5:2- i.e. five days of normal eating and two days of fasting. Constance-based sports scientist, author and health advisor Dr. Michael Despeghel represents the 5:2-Methode and recommends to reduce the calorie supply on two days of the week to 500 calories per day; on the other five days one eats however completely normally. The 6:1 diet is virtually the softer version of the 5:2 diet. The basic idea remains the same: save a portion of the weekly calories by abstaining from food and thus lose weight.
From extreme chamfering variants is to be advised against
From extreme variants like "Alternate Day Fasting (36/12)" is to be advised against, since long hunger phases stress the body very much. With all variants applies: the failed food not by unrestrained Schlemmen "again purely get". Fat- and protein-based first meals after the fasting window help against cravings, for example. B. Omelet with feta cheese.
Who suffers from chronic illnesses such as diabetes, eating disturbances or cycle problems, which should leave please completely the fingers from more extreme chamfering variants – and/or at least before with its physician to have spoken!
For whom is interval fasting suitable?
Interval fasting is basically suitable for all- provided that one can keep up chamfering times and integrate it into the weekly routine, explains Dr. Riedl. And that is not so difficult: Who does not want to do without the Sunday brunch, fasts for example on weekdays. And those who constantly have to attend business lunches during the week, just fast on the weekend.
If it is clear, on which days one is to be fasted, one plans, which it on these days to eat and drink to give is. Dr. For example, Despeghel eats a high-protein meal once a day to provide his body with a minimum of energy and prevent muscle breakdown.
Cleverly it is also to log first successes For motivational purposes. If you choose the 2:5 method instead of the 16:8 method, it is especially important to drink a lot on the fasting days: ideally water, tea and vegetable broth.
Fasting and exercise- goes that?
Sport is also said to be a good idea during the fasting phase. „Sitting drives the blood sugar level upward", says Dr. Despeghel. Movement however strengthens apart from the calorie burn also the well-being and shows the chamfering achievement strength.
The body is forced to fall back on its reserves, fat burning is optimized, and even stubborn fat deposits in problem areas can melt away. Fitness trainer Fritzsche also confirms that training on an empty stomach is "one of the best fat burning strategies of all" be. However there are also here Gegenmeinungen. One warns among other things of a sinking blood sugar level as well as resulting dizziness. The quality of training could also suffer.
Important note: People suffering from chronic diseases such as diabetes should never make such dietary changes without consulting a doctor.
Is interval fasting better than other diets?
Some scientific studies had suggested that as a result of intermittent fasting, certain metabolic values improve more significantly than with a conventional diet, in which fewer calories are consumed each day for a longer period of time. The scientists have now tested this assumption. They enrolled 150overweight and obese people between the ages of 35 and 65 in their study and randomly assigned them to one of three groups.
Thus the study ran off
The participants in the first group did interval fasting according to the 5:2 method and reduced their weekly energy intake by 20 percent in this way. The participants in the second group maintained a normal diet by consuming 20 percent less energy each day. The remaining study participants ate further as always. All were given detailed information at the beginning of the examination on healthy eating and, if necessary, how to carry out their diets. In addition, the researchers determined numerous measured values, such as weight, fat distribution, blood pressure and numerous metabolic values.
During the first three months, the participants were interviewed every two weeks by telephone about their experiences and encouraged to persevere. Following the actual test phase, the participants came back to the study center for another examination. They were again encouraged to continue, but then received no further calls. The scientists observed the participants for a total of 50 weeks and recorded their weight and state of health.
This is what the analysis of the data showed at the end
The evaluation of the data proved that there were no significant differences between the two diet variants in terms of weight loss and that the metabolism had also changed in a very similar way: "In the subjects of both groups, visceral fat, i.e. unhealthy abdominal fat, decreased with body weight, as did fat deposits in the liver", explains Schubel. The scientists also found no difference in the activity of certain genes associated with the adverse health effects of obesity.
Only in terms of glucose levels were there significant differences between the two diet methods: After 12 weeks, participants who ate less each day had significantly lower blood glucose levels.
How to manage to keep the weight off in the long term?
When losing weight, it’s probably not so much the type of diet that matters, but primarily deciding on a type and then sticking to it, the scientists conclude. It seems that "some people find it easier to be very disciplined on two days instead of counting calories and restricting themselves every day," Schubel explains, says study leader Tilman Kuhn. In order to maintain the weight in the long term, however, a long-term change in diet according to the recommendations of the German Society for Nutrition (DGE) would be required.
The professional society sees the trend to interval fasting rather critically. „Most concepts of the Intervallfastens contain no or only very vague recommendations for the food selection. Therefore alone by the intermittent chamfering usually no nourishing conversion takes place to a nourish-physiologically favorable Lebensmitteauswahl ?, it says there. And fasting is unsuitable for losing weight.