One of the biggest challenges for people on diet is how to lose weight and keep it off, because we know it too well: if losing weight is hard, to keep in shape afterwards is even more difficult.
Gaining back all the lost pounds could be due to an altered nerve stimulus: this is the suggestive hypothesis that Australian researchers have so far tested in laboratory mice. But, in humans, good habits can also change the nerve impulses.
This is the common experience that many obese people tell:
"The diet was effective, but in a short time I gained back all the pounds I lost."
I bet that every nutritionist must have heard this from some of their patients, and I also imagine that it's not easy to answer why that happened, especially if the patients followed the advice to the letter.
Anyway, experts have been trying to find an answer to why overweight people (or obese) have such a hard time trying to lose weight and keep it off.
Research on How to Lose Weight and Keep it Off
What if the cause of gaining weight again wasn't the food that people eat but a nervous stimulus?
The idea comes from a study published in the International Journal of Obesity and conducted on mice.
Researchers at the University of Adelaide have found that the alteration of the afferent fibers of the vagus nerve, induced by a high fat diet, did not allow the signal transmitted through the leptin - the hormone released by adipose tissue that induces the feeling of satiety - arrived at their destination.
The research showed that the lesions of the nervous fiber - able to control the motility of the stomach and a part of the intestine - was only partially reversible following a diet change: which, consequently, acquires only a potential role for body weight maintenance.
Are Obese "Doomed" Then?
The research, conducted on mice, reveals how important it is not to go on diet only when the situation is already really bad. But that doesn't mean that every single try is going to fail.
"The systems that regulate hunger and satiety in humans are much more complex than those of mice", say the researchers.
In this study, only three types of diet were tested: standard, high fat content and a third consisting of an alteration of the two previous ones.
We can not draw any conclusions about the effects of any low calorie diet recommended for those who have an urgent need to lose weight.
Obesity, however, should not be addressed only through a diet, but through a radical change in lifestyle that includes also increased physical activity and modification of other bad habits.
The Role of the Nervous System
In both mice and humans the hypothalamus controls the sensations of hunger, appetite and satiety.
Consequently the nervous system has a role in becoming obese or overweight in general. However, eating habits can, with time, also change the behavior of the nerve centers involved through neuronal plasticity.
In fact, researchers also state that "You can not think that they (nerve centers) are unrelated to the physiology of the organism and our eating habits. Nerve centers that control hunger and satiety are "forged" by feeding behavior, especially in children, whose neuronal plasticity is very high".
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