Lack of Protein in Diet Makes People Overeat

Humans are hard-wired to crave for protein, a new study from Australia has reported. Limiting protein-rich food leads people to eating more calories than they actually require.

In the current study, researchers analyzed data from 38 published experimental trials. In all the studies, participants had unrestricted energy intake.

"We found that regardless of your age or BMI, your appetite for protein is so strong that you will keep eating until you get enough protein, which could mean you're eating much more than you should," says Dr Alison Gosby, lead author of the research and a Postdoctoral Fellow at the University of Sydney's Charles Perkins Centre.

When people consume food rich in carbohydrates and fats, their protein intake decreases, resulting in higher energy input that leads to weight gain.

"For example, when you consume things like soft drinks, which are fairly low in proportion of protein but high in calories, your energy intake will increase because you'll need to keep eating to get the protein you need. If you add a soft drink to your lunch then you've added a lot of calories, but you'll still have to eat the same amount of food," Dr Gosby said in a news release.

The idea of brain wanting more protein isn't new. Research has shown that it was meat and cooked food that helped humans evolve dramatically over a period of few million years.

Previous research has shown that increase in protein intake with a constant carbohydrate intake led to significant weight loss. 

Another study from the Journal of Nutrition Education and Behavior, had earlier shown that women who increased protein levels in diet shed more weight than others.

Gosby and team aren't saying that people should eat more proteins as a regular Western diet has enough of protein. Instead, the research could helped design dietary recommendations for overweight and obese people.

"We do not advocate a high-protein diet, which we generally find to be unsustainable, but instead urge people to follow a balanced diet and eat healthily," Dr Gosby added.

The study is published in the journal Obesity Reviews.