The fatter you are, the harder it is to lose weight

You're not imagining it: your body really does fight against your attempts to lose weight, according to new research from the University of Cambridge.

Researchers found that the more you weigh, the more your body appears to produce a protein called sLR11, which actively inhibits your ability to burn fat.

Researchers slowly transitioned two groups of mice from a low-calorie diet to a high-calorie diet, and measured how their bodies reacted.

The results showed that mice who lacked the sLR11 protein burned excess calories faster than those who were rich in the protein, who simply put on more weight.

Researchers then turned their attention to humans and found a similar correlation – those who had a greater total fat mass displayed a high level of sLR11 and found losing weight a harder task than those who didn’t.

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Dr Andrew Whittle, the author of the study, believes the finding gives an insight on how to effectively fight rising obesity levels.

"Our discovery may help explain why overweight individuals find it incredibly hard to lose weight," said Whittle.

"Their stored fat is actively fighting against their efforts to burn it off at the molecular level."

The researchers showed that sLR11 increases total fat mass in the expectation that you will need it during cold periods to stay warm.

Professor Toni Vidal-Puig, who led the team of researchers, believes that this finding may benefit people with all kinds of metabolic diseases – including anorexia.

 "We have found an important mechanism that could be targeted not just to help increase people's ability to burn fat, but also help people with conditions where saving energy is important such as anorexia nervosa," says Vidal-Puig.

These findings could stimulate the development of new-generation fat fighting drugs that actively block the sLR11 protein, say experts.

Jeremy Pearson, associate medical director at the British Heart Foundation (BHF), was ecstatic at the findings.

"This research could stimulate the development of new drugs that either help reduce obesity, by blocking the action of this protein, or control weight loss by mimicking its action," says Pearson.