Fasting to lose weight? Bad idea. This method, in fact, not only does not make you lose weight and does not bring any benefit in terms of circulating cholesterol, blood sugar and blood pressure, but it can also reduce muscle mass. This emerges from a very recent review that appeared in the journal Nutrition Reviews thanks to the work of an American team from the University of Illinois Chicago (Ezpeleta et al, Nutrition Reviews, June 2023).
Obesity and fasting
Therefore, overweight and obesity must certainly be counteracted. But they must be counteracted in a healthy way. How many skip meals or drink only water, juices and soups for days to reduce body weight? Maybe, at the beginning, they even reach their goal, but the result is ephemeral and soon everything goes back to the way it was before, if not worse. This is what the review that is today's topic talks about.
The risks of fasting, what science says
The review analyzed the results of previous studies on the effects of fasting on body weight and on some parameters such as cholesterol, blood sugar and blood pressure. The research focused on very strict fasting practices, such as drinking only water or following the Buchinger fasting, which consists of taking, in addition to water and tea, a vegetable soup and a glass of fruit juice a day. What has emerged is that, effectively, these fasting practices lead, at least immediately, to a reduction in body weight of about 6% if you continue to fast for 5 days. However, as mentioned, the results are ephemeral and as soon as you return to eating normally, which, it should be emphasized, is essential to ensure your body has energy and nutrients without which it would not be able to perform its functions, you'll gain back all you have lost within three months. Only further calorie restriction, which is not very feasible since eating is necessary to live and one cannot live with a constant feeling of hunger, can reduce the weight gain. In addition, values such as cholesterol, blood sugar and blood pressure, even if decreased during fasting, come back as before once you resume eating. Not only that, fasting in this way leads to a reduction in weight not in the desired way, as it is the muscles that are reduced, while the destruction of muscle proteins increases. In other words, the body needs proteins and, when these are not supplied, it looks for them where they are available, namely in the muscles, which weaken and this is certainly not the result we want to achieve.
Fasting, intermittent fasting and other remedies against obesity, conclusions
Fasting is therefore not the way to lose weight. At the cost of great sacrifices, it does not achieve the desired results and moreover it damages the muscles. In addition to these excessive fasts, which unfortunately are often also applied by people independently, there is also intermittent fasting which is talked about a lot. We have also dedicated an article to intermittent fasting in which it emerges that, based on studies, this can actually lead to weight loss but only in the case of proven obesity, otherwise it can alter the hormonal profile and increase insulin resistance (Kalam et al, Obesity, 2022 - Heilbronn et al, Obes Res, 2005). In any case, intermittent fasting should only be done under the strict supervision of a specialist, who will also have to assess the person's state of health. In any case, the best choice remains to follow an active life, with moderate physical exercise and a healthy, balanced diet, limiting refined foods and sugars but favoring fruit, vegetables, whole grains and legumes, green tea and spices. In this way we ensure that our body receives essential nutrients for life, improve mood, which is also important, and avoid ailments such as headaches, hunger and insomnia, which accompany any continuous or intermittent fasting regimen.