According to a new study, without medical monitoring, the practice of fasting would not necessarily be positive for health because, beyond the weight loss which occurs quickly, the benefits would only be visible from the fourth day .
- On average, participants in the seven-day fast, during which they could only drink water, lost 5.7 kilos.
- The researchers point out that weight loss occurred during the first three days of fasting and then remained stable.
- As for the health benefits, these were only visible from the fourth day.
Its benefits have been touted for several years and yet, fasting could be dangerous for your health, according to a new study published in the journal Nature Metabolism.
A weight loss of 5.7 kilos
Several types of fasting exist. Some are called prolonged, by restricting calorie intake for several days, or intermittent, by not eating for several hours of the day. Generally, the formula chosen for the latter is a food break of sixteen hours per day, which therefore requires skipping a meal.
In their study, the researchers analyzed the impact of prolonged fasting on twelve healthy people, five women and seven men. Participants underwent a water fast for seven days, meaning they could drink water as much as they wanted but could not eat. Blood samples were taken before, during and after this seven-day period.
Results of the experiment: on average, participants lost 5.7 kilos. But the researchers note that the weight loss occurred during the first three days of fasting and remained stable thereafter. Then, it is only from the fourth day that patients experience positive effects on health, particularly cardiovascular health, as well as a reduction in inflammation linked to rheumatoid arthritis. Finally, at the end of the fast, blood tests showed “deep systemic changes” out of the 3,000 proteins measured.
“For the first time we can see what happens at the molecular level throughout the body when we fastindicates Claudia Langenberg, author of the study and epidemiologist at Queen Mary University of London, in a communicated. Fasting, when done safely, is effective for weight loss. Our results show health benefits of fasting beyond weight loss, but these were only visible after three days of total calorie restriction, later than previously thought.“
Fasting is good for your health, under medical supervision
So, is fasting a good idea? Yes, say the researchers, but on condition that it is medically supervised. Indeed, calorie deprivation, particularly in the event of prolonged fasting, can impact health: deficiencies, hyponatremia (the decrease in plasma sodium concentration due to an excess of water compared to sodium) or, conversely, dehydration because hydraulic intake also comes from food.
Medical monitoring is all the more important as fasting is not suitable for all patients. “Although fasting can be beneficial for treating certain illnesses, it is often not an option for patients with medical conditions, explains Maik Pietzner, one of the authors. We hope that these results can provide information about why fasting is beneficial in certain cases, which can then be used to develop treatments that patients can follow.”
