If there was a pill to fill you up would you use it?

Scientists in the US have discovered that they can increase metabolic rate in mice by giving them a drug called Fexamine (Fex) that apparently increases their metabolic rate (rate of using energy). The results were published in Nature Medicine last week. This was widely reported in the media last week as:

“Step away from the burger now you can feel full by just taking a pill”

“Diet pill that makes you feel full proven to keep weight off in mice, scientists say”

“'Imaginary meal' diet pill tricks body into losing weight”

“ ‘Fake meal' pill uses phantom calories to fight obesity”

But are these claims correct?

Not exactly!

The scientists tested a drug called Fex ,which acts on a body receptor that is involved in metabolism (no one knows exactly what it does). Previously this drug had not had a positive effect, as it didn’t just act on metabolism in the gut. It also acted in the kidneys, liver, intestines and bowel, gall bladder as well as white and brown fatty tissue (called adipose tissue).

These scientists gave the drug orally and found it wasn’t absorbed properly and therefore only acted in the gut. This led to improved results.

What effect did the drug have?

There were no differences observed in mice of a normal weight between the Fex treated mice and the controls. A second group of mice were fed a high fat diet to make them obese. The obese mice treated with Fex had improved metabolism including a slowing of weight gain on the high fat diet (they didn’t lose weight though), increased insulin sensitivity and reduced inflammation. They also had more brown adipose tissue (a type of body fat which is “healthy”) and less white adipose tissue (the “unhealthy” body fat) than the controls.

Will this drug help me lose weight?

As all of the reporters stated the experiment was in mice, not humans – so any potential treatments are probably a long way off.

But secondly and more importantly none of the mice who were treated with the drug ate less or lost weight.

Would I give up food and take the drug to feel full?

No. The headlines were misleading. If this drug is ever developed into something people can take it would be more likely to increase your metabolic rate but is unlikely to make you feel fuller (remember the mice did not eat less when given the drug).

What pharmaceutical options are available for weight loss?

Currently the only weight loss drug available on prescription in Australia is Orlistat. It stops you absorbing 1/3 of the fat you eat with some fairly nasty side effects (the fat has to go somewhere) and therefore teaches you to eat less fat. It has a roll for people who have tried diet and exercise only therapies without success. Orlistat should only be used under medical supervision.

The best way to lose weight is still to eat well and move more. A healthy balanced diet is not only a lot tastier than a pill, it looks better, helps you socialise better and it will fill you up. Importantly a balanced diet also means you eat enough fibre, vitamins and minerals to keep you healthy and well.