Is intermittent fasting good for your health?

Is it educational to stop eating (fasting) to learn how to eat? We could answer with another question: is it educational to stop playing the violin to learn to be a violinist? We do not have studies that allow us to answer these questions, but it does not seem very adventurous the hypothesis that to stop eating does not educate to learn to eat, just as stopping playing the violin does not help to learn how to interpret the first movement of Concert for Violin in C. 35 of Chaicovski.

The above two questions actually, we could rephrase them like this: does it bring health to stop eating (fasting)? does it make us violin virtuosos to stop playing it? Although the second question seems absurd, the first question is not, given that interest in the so-called "intermittent fasting diet" is increasing according to Google Trends. It's easy to answer the first question, because we have the review of the NutriMedia health portal.

The president of Harvard's nutrition department considers it chimerical that caloric restriction allows body weight to be controlled

NutriMedia is a project of the Observatory of Scientific Communication of the Universitat Pompeu Fabra, with the collaboration of the Centro Cochrane Iberoamérica, the Spanish Academy of Nutrition and Dietetics and the Spanish Foundation for Science and Technology. His research, titled "Sporadic fasting Is Health Benefits?", concludes: "Science does not endorse the purported goodness of fasting for health and weight reduction.


Are there studies on intermittent fasting? No doubt, and many say it looks like a promising proposition. Why? Because they can't claim it works. Which leads us to a reflection by Ted Kyle on this issue, which we found in his text The mundane miracle of intermittent fasting ("The mundane miracle of intermitent fasting"): "It is important to remember this: many great ideas that never worked are muddying the landscape of clinical research.


No clinical trial, clinical guide or posture document has been published since the publication of the NutriMedia review (September 2018) to today, no clinical guide or posture document has been published to contradict its conclusion, so we have to give it as valid and flee to the career of those who assure us that this proposal develops muscles, cures hypertension, "depuras" us, slows down aging, improves cognitive function or makes us sylfides. On intermittent fasting and obesity is nothing better than reading the text "intermittent fast: when dieting consists of not eating", by journalist Laura Caorsi (who has statements from nutritionist Eduard Baladia) and the verdict of the American Institute for Cancer Research(): "This diet can be difficult to maintain in the long term and once it is abandoned, the weight will probably return".".it can be difficult to maintain in the long term and once it is abandoned, the weight will probably return".".it can be difficult to maintain in the long term and once it is abandoned, the weight will probably come back

Its safety or long-term health consequences have not been well assessed: "It may cause significant side effects"

In any case, the scientific literature has spoken of fasting or intermittent fasting since the publication of Nutrimedia. Thus, a review by Emily Levy and Thomas Chu at Current Sports Medicine Reports concludes that intermittent fasting does not exert benefits on athletic performance. We also have research from Philippine Fassier and collaborators in International Journal of Cancer in which although fasting is recognized to be common in cancer patients, it is discouraged for two reasons: not having established any benefit and associated with sarcopenia and malnutrition, which can seriously worsen the prognosis of the disease, as justified in the book Diet and Cancer. Finally, we cannot ignore the publication of Dr. Fank Hu, president of the nutrition department at Harvard University at Lancet Diabetes & Endocrinology. Hu believes that it is chimerical to expect that the caloric restriction will allow us to control body weight and that it makes much more sense, on the one hand, following a good lifestyle (in his words: "leanness induced by healthy lifestyles", that is, thinness induced by healthy lifestyles) and, on the other hand, not delegating so much the responsibility of obesity to the individual (something that can generate frustration and guilt) but rather to policy makers. The latter question is expanded by the book "The Right of Nutrition".

But NutriMedia has not only found no justification for the purported benefits of intermittent fasting, it also insists that its safety or its long-term health consequences have not been well assessed. In this sense it details that it "may cause significant adverse effects". According to the NHS (UK National Health Service) portal and according to a systematic review by Benjamin D. Horne and colleagues in The American Journal of Clinical Nutrition intermittent fasting can lead to annoying symptomatology, such as poor breath, irritability or difficulty in concentration, to more worrying effects, such as sleep disorders, dehydration or nutritional deficiencies. Let's adding that in the long run fasts can increase, according to the study by Horne and colleagues, the risk of something much more worrying than bad breath: eating disorders. Disorders that are very difficult to address and also difficult to prognosis. That is why the NHS portal does not hesitate to clearly discourage this proposal to pregnant women, people with diabetes or those who have an eating disorder or are at risk of it.

This brings us to the precautionary principle, which we find in the General Law on Public Health. That in this case means that because the supposed benefits of intermittent fasting do not compensate for its risks, the wisest thing is to fast from the intermeding fasting. Maximum when we have much more sensible and, above all, more sustainable long-term dietary proposals, such as the one recently proposed by the Generalitat de Catalunya in its guide "Small changes to eat better". Their recommendations are more logical, have more scientific support, are healthier and, above all, do not put our health at risk.

Finally, as many sick people use fad diets to treat their pathologies, it is necessary to remember that any disease must be properly diagnosed and treated (by accredited and qualified health professionals) with approaches that have strong evidence of efficacy and safety.