Weight: what causes the yoyo effect?
The French are rather concerned about their weight (1) : a large majority (63%) admit to paying attention to it, 44% have already followed a diet with the aim of losing weight and 26% have already followed several. However, half of the French population is overweight (2) : 56.8% of men and 40% of women are overweight (overweight or obesity). A strange correlation, which could be explained, among other things, by the yoyo effect. But what are the causes of this rebound effect which directly affects weight and, in extenso, health? And above all, how to avoid it?
What is the yoyo effect?
The yoyo effect is a process that describes rapid weight loss , but is followed by equally rapid and often greater weight regain than the loss. It can be described as a “vicious circle” of weight because, if it is renewed, it generally generates more and more substantial weight loss and recovery. The phenomenon is therefore an aggravating factor of overweight . It is an open door to obesity and systematically leads to a modification of the muscle-fat ratio in the subject. Its other consequences are the modification of the distribution of body fat , a drop in the metabolic rate at rest and an increased difficulty in losing weight . Not to mention the psychological impact, since weight loss and regain affect the person and can lead to depression and eating disorders .
But the yoyo effect is above all a “defense” mechanism of the body. If the body is deprived of part of its energy intake (which happens when you go on a diet), it adapts. Thus it reduces its level of metabolic expenditure and draws on its reserves. Except that when the energy intake returns to normal (the resumption of its usual diet), the body does not know what to do with these calories . Thus, it stores them as subcutaneous fat. Weight gain is inevitable.
Yoyo effect: how does metabolism work?
The yoyo effect is actually based on the slowing down of basal metabolism . Basal metabolism corresponds to the body’s incompressible energy needs to function optimally, at rest. The body needs a number of calories every day to perform its vital functions: brain activity, breathing , heart pump, digestive function, nutrient metabolism, maintaining body temperature , cell renewal and muscle activity.
Certain factors slow down the metabolism . The most common is aging, since it naturally involves muscle wasting (on average -40% between 40 and 90 years old), a drop in the secretion of hormones (such as growth hormones), a weakening of the immune system ( and a higher propensity for inflammation), less assimilation of nutrients from food. However, rapid, diet -induced weight loss , illness or food deprivation, can also cause this slowdown. But what does this have to do with the yoyo effect? It is very simple: when resuming a “normal” diet, or at least richer than that which was adopted during the diet period (chosen or undergone), the metabolism does not accelerate. He stays low. Thus, the calories absorbed are not used by the body, but stored by the latter, for a new period of diet. The yoyo effect kicks in, and you regain the lost weight (or even more). Thus, the basal metabolic state explains the yoyo effect.
What are the causes of the yoyo effect?
An overly restrictive diet
This is obviously the most common cause of the yoyo effect. Restrictive diets are harsh on the body. Of course, by creating a caloric deficit, we lose weight, since we force the body to draw on its reserves. But what is less known is that the body draws first from its muscle reserves before using its fat reserves. Result: a severe low-calorie diet will systematically lead to muscle wasting, and therefore a yoyo effect, once the “normal” diet is resumed (the muscle being a large consumer of energy). And the more restrictive the diet, the greater the rebound will be.
A totally anarchic post-diet diet
The repetition of restrictive diets is the No. 1 cause of the yoyo effect, but it is even worse if the resumption of a “normal” diet is brutal and anarchic. The body, hypocalorie for weeks, will not be able to cope with the influx of calories. But the head will also have been frustrated: we will be much more tempted to “catch up” and eat in an absolutely unreasonable way. Result: substantial, rapid, uncontrolled weight gain that is extremely harmful to the body.
Disease
The diet undergone that involves certain diseases, associated with inflammation, slow down the metabolism. We particularly think of seasonal ailments (flu, cold, gastroenteritis) but also of psychiatric illnesses (anxiety, depression, bipolarity), cancer or eating disorders. They generally disturb feelings of hunger and satiety , so that they sometimes lead to rapid weight loss. Healing (or stabilization of the pathology) generally involves resuming a normal diet. But it can also give rise to a yoyo effect, especially if the episodes of illness are repeated.
A lack of balanced diet
Another cause, more subtle: the absence of a balanced diet. Some people just don’t have any nutritional benchmarks. So they link healthy weeks and orgy weeks. Nothing like disrupting the body. The body is indeed a creature of habit, which likes neither deprivation nor excess. Force it to alternate between these two extremes, and you’re sure to experience the joys of the yoyo effect: an inability to maintain a healthy weight.
A failing microbiota
A 2016 Israeli study (3) conducted on mice could demonstrate the importance of the intestinal microbiota in the yoyo effect. Indeed, a deficiency in flavonoids in the microbiome could accentuate the yoyo effect: lower energy expenditure, different metabolism of food intake, increased inflammation. A failing or poor intestinal microbiota (low bacteriological diversity) could therefore impact the metabolism and therefore the extent of weight regain.
What to do to avoid the yoyo effect?
To lose weight and stabilize it permanently, some simple measures must be put in place:
Hyper-restrictive and/or exclusive diets are avoided at all costs. An effective diet is a diet that does not exclude any class of food, since each nutrient has a specific function for the body. In addition, a diet prescribing too low a caloric volume will systematically have a deleterious effect on the basal metabolism. Say goodbye to “miracle” diets, which promise rapid and significant weight loss. It is better to lose weight slowly but surely, by adopting a reasoned food rebalancing , which invites you to eat everything, to modify your cooking methods (grilled meat rather than in sauce, pasta al dente rather than very cooked, etc.), to agree a softness from time to time, to favor the fibers …
- We avoid “risky” behaviors, such as nibbling or “binge eating”. Better to eat 4 meals a day than to tighten your belts and crack massively at the slightest frustration.
- We continue physical activity : it not only keeps muscle mass afloat, but also increases energy expenditure. And this physical activity must continue over the long term – during, but also after the food rebalancing.
- We do not neglect our sleep , since it is when we sleep that the hormones of hunger and satiety (ghrelin and leptin) are regulated. In addition, sleep gives rise to tissue restoration (including muscle) and a reduction in inflammation (elimination of free radicals). Also, to avoid the yoyo effect and significant weight gain, we allow ourselves 7 to 8 hours of sleep per night.
Stephen Paul is the lead author and founder of My Health Sponsor. Holder of a diploma in health and well-being coaching with more than 200 articles in the field of health, he makes it a point of honor to offer advice based on reliable information, based on scientific research, and verified by health professionals.