Weight loss, weight gain
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After working hard for months by following stricter diets and doing rigorous physical exercises to shed weight and achieve the desired look, what could scare the hell out of you? Those extra kilos coming back; Isn't it?

A recent study has revealed that hormones are to be blamed for it.

Researchers from Norway and Denmark tracked the fitness, body mass index (BMI), hormone concentrations, and reported hunger levels of 35 adults over two years.

Each of the volunteers was severely obese when they entered the programme. After joining the program they underwent a rigorous weight loss regime involving a calorie-restricted diet, exercise, and therapy.

After a three week residential session, the study participants went home where they continued to exercise and eat healthy.

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Two years later it was found that all of the subjects have successfully lost significant amounts of weight, but their hormones and reported feelings of fullness and hunger told a different story.

It was noted that a month after weight loss programme, the study participants felt fuller after meals, and experienced no significant change in their hunger levels when they fasted. Along with this, researchers noticed higher levels of a hormone known as peptide YY – it shuts down appetite when released in the gut.

However, after one year, those feelings reversed as hunger levels and a desire to eat steadily increased. The worse thing noted was, it remained high after another twelve months.

In other words, the study showed that in the initial days the efforts in changing diet and exercise actually showed results with a depressed appetite, but soon hunger pangs took over.

The exact mechanisms behind the hormone changes are not known, even the researchers admit that they don't have enough information to comment on the energy balance of the participants at the time measurements were taken, Science Alert reported.

However, research like this shows how complex weight loss can be and also provides hope that with such knowledge there might be a solution to it in the future.

This research was published in American Journal of Physiology-Endocrinology and Metabolism.