PEOPLE who stay on the high-protein Atkins diet for too long could be harming their heart, kidneys and bones, Australian doctors say.

The high-protein, low-carbohydrate diet, popular among Hollywood celebrities, has been shown to reduce weight in the short term.

But Monash University Associate Professor Malcolm Riley said doubts remained about the long-term impacts of the Atkins diet. 

“There still remains question marks over whether, for various population groups, there might be adverse effects,” he said yesterday.

“And if there are those adverse effects, they’re likely to be in the area of cardiovascular, possibly renal and possibly osteoporosis.”

In a paper published in the Australian Medical Journal, Professor Riley and Flinders University’s Associate Professor John Coveney suggested the low-carbohydrate diet appeared to be safe for up to 12 months with no obvious effects on cardiovascular risk factors or blood pressure.

Beyond that, the risks were unclear.

Atkins dieters were more likely than people on other diets to suffer bad breath, headaches and constipation.

The diet worked for people whose short-term goal was to simply lose weight. Those on a low-carbohydrate diet lost 4kg to 6kg more than people on a low-fat diet over six months, but over 12 months there was no difference between the two, Professor Riley said.

He warned the Atkins diet was difficult to stick to and yo-yo dieting could be more dangerous than maintaining a relatively high weight.

“The main problem with diets is people don’t stick to them,” he said.

“It’s a matter for individuals to find out whatever they can do to change their lifestyle in a way they can maintain. One of the main reasons people diet is cosmetic reasons, they want to look better.

“If health was their main concern, it is probably easier to be fit at any weight than to lose weight to a certain target weight.”