Intermittent fasting does not beat low-calorie diets in cases of obesity and severe overweight

If this is not a rejection, it is a close call. The enthusiasm for intermittent fasting in its various forms is cooling. After much anticipation, models proposed on social media, and anecdotally indicated prospects for weight loss, the numbers of a major scientific study greatly reduce the hopes of combating overweight and obesity linked to intermittent fasting. It is a Cochrane review of the available studies that sanctions this judgement, with an opinion that leaves no room for much discussion, even though it was gathered on not very large numbers of patients. Summary conclusion: those who follow intermittent fasting in order not to blush on the scales should not expect different results from what traditional low-calorie diets can offer in terms of metabolic benefits and rapidly dropping kilos. And there is also some pitfall, since this mode of food intake could also prompt tendencies towards a sub-optimal relationship with food in predisposed individuals.

The study, co-ordinated by Luis Garegnani and Eva Madrid as lead author, from the Associated Cochrane Centre of the Universidad Hospital Italiano de Buenos Aires, examined observations from 22 randomised clinical trials on a population of almost 2000 subjects in North America, Europe, China, Australia and South America. The studies examined different forms of intermittent fasting, including every other day fasting, periodic fasting and time-restricted fasting (i.e. meals concentrated in a limited time of day, followed by a large break without touching food). Most of the studies followed participants for up to 12 months. The review compared intermittent fasting with traditional dietary advice and with no intervention. And unfortunately, the evaluation dampened enthusiasm, so much so that Garegnani himself said that intermittent fasting does not appear to have a clinically significant effect on weight loss compared to the other two options (classic diets or doing nothing). 'It does not seem to work for overweight or obese adults trying to lose weight,' is the expert's opinion.

"Intermittent fasting is a relatively new approach to weight loss," the researchers report. It involves periods when people eat little or no food (fasting), followed by periods when they eat normally'. In this sense, of course, the pattern can vary, from taking food only during a certain time slot, fasting on certain days of the week or alternating between days when one eats normally and days when one eats very little. Some observations report that this eating pattern may have benefits on some biological aspects, but it is not clear whether it is better than a conventional diet for losing weight in obese or overweight people.

Once again, therefore, it is confirmed that the nutritional approach should always be made by a specialist and not simply 'copied' on the basis of general indications, whether they are conveyed by socialites or influencers. Let's be clear. the analysis of the data, due to the narrowness of the sample examined, does not allow a clear final verdict. But care is needed. and above all, one should not choose food models 'blindfolded'. The authors of the study themselves are convinced of this, so much so that they point out, as Garegnani says, that 'intermittent fasting may be a reasonable option for some people, but the current evidence does not justify the enthusiasm we see on social media'. Above all, according to science, there are no shortcuts when it comes to obesity, a chronic disease that must be addressed as such. This is very important. And once again it signals how much and how a tailor-made approach is needed. 'With the evidence currently available,' concludes senior author Eva Madrid, of the Cochrane Evidence Synthesis Unit Iberoamerica, 'it is difficult to make a general recommendation. Physicians will have to assess on a case-by-case basis when advising an overweight adult to lose kilos'.