The excitement around intermittent fasting comes mainly from two results, according to Benoît Lamarche, professor at the School of Nutrition at Laval University and scientific director of the NUTRISS center. These two results have been repeated in the scientific literature almost systematically, he says. Hence their interest.
First, there are animal studies, which have shown that mice subjected to dietary control and intermittent fasting live longer than others. Researchers then became interested in the impact of intermittent fasting in humans, and their studies showed that by following an intermittent fasting protocol (which can take different forms), people lose weight quickly.
“When we eat fewer calories, we will lose weight – this is clearly demonstrated in the literature, there is no debate on it”, summarizes Benoît Lamarche, who is interested in his research in impacts of diet on cardiometabolic health and cardiovascular risk. “The big debate is about the challenges we encounter when we embark on diets like this. »
The first challenge (“enormous”, according to Benoît Lamarche) is maintaining a restrictive diet such as intermittent fasting over time. “Several studies show that adherence erodes over time,” he summarizes. Socially, culturally, it’s difficult to maintain these habits long term – whether it’s not eating anything between 8 p.m. and noon or doing entire days of fasting.
When we increase the number of calories, the body, which was “in sleep mode”, stores the surplus, the researcher popularizes. “The risk of gaining weight is enormous, unless you really find the sweet spot of energy balance,” explains Benoît Lamarche.
When you make nutritional changes, it only takes a few days to see health benefits (cholesterol, blood pressure, etc.), but the opposite is also true: you lose the gains quickly when you go back to your old ways. habits.
Benoît Lamarche targets another challenge associated with intermittent fasting: that of meeting your nutritional needs. If we cut out foods, we also cut out essential vitamins, minerals and nutrients.
To add to the confusion, remember that in the 1980s and 1990s, Canadian researchers published studies showing that, to control your blood sugar, it was better to eat several small snacks per day than three large meals. “It’s completely contradictory with the notion of intermittent fasting,” emphasizes Benoît Lamarche.
Let’s return to our reader’s question. What is the healthiest approach? Long-term health success, according to Benoît Lamarche, is eating in a balanced way, to meet your energy needs (without exceeding them) and your nutritional needs.
The big nutritional challenges on the planet are the consumption of vegetables, fruits, plant proteins, nuts, whole grains, etc. And what we eat too much of are, first and foremost, ultra-processed products, the source of 40% to 50% of the calories consumed by Canadians.
“Is this easy to do? No,” agrees Benoît Lamarche. Ultra-processed products are everywhere in our food environment and they are affordable. Collectively, we also lose the ability to cook for ourselves, he says. When you eat out often, the quality of your diet suffers.
Intuitive eating is another trend that is gaining momentum, but adopting it is not a simple thing, agrees Benoît Lamarche, who recalls that many people no longer really recognize their hunger signals. “So how do we do it? It is first of all about being aware of it, and also being supported, to be able to make lasting changes, indicates Benoît Lamarche. There is no magic recipe. It’s unfortunate, but that’s it. »