In recent years, intermittent fasting has won over millions of people around the world. Time-limited eating (the famous 16:8 method), alternating fasting, 5:2 protocol, there are many variations, but the principle is always the same: alternating periods of fasting or very reduced calorie intake with phases of normal eating.
Those who practice it swear they feel lighter, more energetic, and are finally able to lose those extra pounds without having to count every single calorie. In fact, intermittent fasting has been associated with potential metabolic benefits: improved insulin sensitivity, reduced inflammatory markers, and, of course, much-desired weight loss.
But is it really like that?
The study
A systematic review published by Cochrane – one of the most authoritative bodies in the evaluation of scientific evidence – analyzed 22 randomized clinical trials involving a total of 1,995 obese or overweight adults. The studies were conducted in Europe, North America, China, Australia and South America, and participants were followed at home or in their community.
The goal was to understand whether intermittent fasting really works better than traditional dietary advice (such as reducing calories or balancing macronutrients) or, even, than doing nothing.
The answer, according to the evidence collected, is less exciting than supporters of intermittent fasting would like to hear.
When compared with the traditional diet, intermittent fasting showed no significant advantages: out of 21 studies involving 1,430 people, weight loss and quality of life were substantially similar between those who followed fasting and those who followed classic dietary advice. In other words, both approaches can work, but neither seems to clearly prevail over the other.
The comparison with no intervention gave similar results: in 6 studies with 427 participants, following intermittent fasting produced little or no difference compared to those who did not receive any dietary indications.
As for side effects, some studies report episodes of tiredness, headache or nausea. However, the available evidence is not yet sufficient to draw definitive conclusions.
One striking fact, however, is that none of the studies measured participants’ satisfaction, diabetes status or overall well-being, variables which, for those living with overweight or obesity, are anything but secondary.
What does it mean
What the study highlights does not mean that intermittent fasting is useless or harmful but that, at the moment, there is no solid evidence that it is superior to other weight loss strategies.
If the 16:8 or 5:2 method fits well with your lifestyle, you find it sustainable and you have no medical contraindications, you may still benefit from it, simply because it helps you eat less naturally. But if you are following it convinced that it is a magic formula that traditional diets cannot offer, science, at least for now, does not prove you right.
Weight loss remains a complex and deeply individual issue. And the thing that works best, as often happens, is probably the one you can maintain over time.
