This could be the dream of any junk food lover and sport hating couch potato: becoming slim without decreasing food consumption. In a research published in the Proceedings of the National Academy of Sciences, an Australian team has found a possible way of losing weight without limiting food intake, a breakthrough that could lead to fat-burning drugs. By manipulating fat cells in mice, the authors managed to increase the rodents' metabolic rate.

When the researchers removed the angiotensin converting enzyme (ACE), the rodents, even when consuming the same food quantity as other mice, burned more calories and were lighter. "Animals without the enzyme were on average 20% lighter than normal mice and had 50 to 60% less body fat," senior researcher Michael Mathai of the Howard Florey Institute told AFP.

"The slimmer mice also appeared to have less chance of developing diabetes because they processed sugar faster than normal mice. The research could be used to develop drugs to assist weight loss," said Mathai, also a lecturer in nutrition at Victoria University. Drugs controlling the activity of ACE can already be found on the market, being employed against hypertension.

"So we know their safety and their tolerability. What we don't know is whether or not they will work in humans. And we don't know whether it will work in all obese humans. It could be a question of finding the right dosage of hypertension medication, or developing a new type of drug of the same class, to be used as weight-loss pills. This might be one way in which you can increase metabolic rate in combination with managing nutrition to limit the intake of calories," said Mathai.

Still, the researchers could not tell the exact pathway of the weight loss. "Because we deleted the gene, the gene is gone from the whole body, that means that it is gone from all tissues including the brain. And so we don't know whether it's a direct effect of the deficiency in the tissue or whether it's something coming from the brain," added Mathai.