Secret behind why you can gain weight again AFTER you lose weight, discovered by scientists

It can be a vicious cycle for dieters – you manage to lose some weight and then quickly put it back on.

Now researchers have discovered why some people get stuck in this endless rut.

People who are obese release less of the “reward” chemical dopamine when they eat, a new study suggests.

At the same time, their brains are less able to register that food is in the stomach — and this effect lasts even after a diet, scientists have found.

The amount and type of food people eat is regulated by complex signals sent between the brain and gut, as well as nutritional signals in the blood.

This network induces feelings of hunger and satiety, regulates food intake and motivation to search for food.

A team led by the Amsterdam University Medical Center injected nutrients, including carbohydrates and fats, into the stomachs of 30 healthy-weight and 30 obese individuals.

Their brain activity was measured and how much dopamine was released.

Results, published in the journal Nature Metabolism, revealed that brain activity and dopamine release were severely blunted in obese participants compared to those with a healthy body weight.

They also found that a 12-week diet, which led to a 10 percent weight loss in the obese participants, was not enough to return these brain responses to normal.

Professor Mireille Serlie, lead researcher, said: ‘Our findings suggest that long-term brain adaptations occur in obese individuals, which may influence eating behaviour.

‘There is a reduced ability of the brain to register that there is food in the stomach, which can lead to overeating.

‘We found that obese people released less dopamine in a part of the brain that is important for the motivational aspect of food intake compared to people with a healthy body weight.

“The fact that these brain responses are not restored after weight loss may explain why most people regain weight after initially successful weight loss.”