The omnipresence of junk food in our daily lives is one of the main factors responsible for the overweight epidemic currently affecting our society. We are exposed to an incredible amount of food products overloaded with sugar and fat (and therefore calories): in the countless fast foods that have invaded our territory, of course, but also in places that normally have nothing to do with food like gas stations.
The wide availability of these high-calorie industrial products, combined with an incessant hype, means that a large number of people eat much more than necessary and accumulate the extra pounds at the same time.
If the waistline of the population has increased dramatically in recent decades, it is not due to any lack of will or laziness; it is above all the result of the “obesogenic” environment in which we live, which encourages us to eat at any time of the day, regardless of where we are.
8 to 12 hours without swallowing anything is enough
An immediate consequence of this food overabundance is to change the structure of meals: rather than eating three times a day, it has become common to “munch” on a small snack at any time, even until late in the evening. And according to a recent study, these snacks scattered throughout the day could greatly contribute to the development of overweight and obesity.
For example, if mice can feed ad libitum at any time during a 24-hour day, they rapidly gain weight and become metabolically unhealthy (prediabetes).
On the other hand, when animals eat the same amount of calories, but for a shorter period (8 to 12 hours), they remain lean and healthy, even when this food is high in sugar and fat.
In other words, it is not only the total quantity of calories ingested that is responsible for overweight, but also the period of time during which meals are spread out.
The intestinal flora has its cycle too
How to explain that a simple 12-hour fast can make such a difference in fat accumulation?
According to a study carried out by the same research group, this protection is due to the beneficial impact of fasting on the circadian rhythms that govern our metabolism. The microbial flora of the intestine is particularly sensitive to these fasting/feeding cycles and it seems that the nocturnal fasting period manages to restore the microbial diversity essential to the metabolism of food consumed during the day.
For example, scientists have observed that obese mice have an unbalanced bacterial flora, but that the simple fact of subjecting them to a 12-hour fast restored the microbial balance and at the same time improved the efficiency of metabolism. .
In other words, the way we assimilate the energy contained in food is greatly influenced by our microbial flora and a fasting/eating cycle repeated every 12 hours is absolutely essential to preserve the proper functioning of this flora.
To stay slim, it is absolutely necessary to respect the complexity of our biological clock and avoid eating anything at any time. And especially avoid snacks before going to bed!
Chaix A et al. Time-restricted feeding is a preventive and therapeutic intervention against various nutritional challenges. Cell Metab; 20:991-1005.
Zarrinpar A et al. Diet and feeding pattern affect the diurnal dynamics of the gut microbiome. Cell Metab. 2014; 20:1006-17.
Read also: Fasting and calorie restriction boost metabolism
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