The controversial Atkins diet is to come under government scrutiny amid growing concern over obesity figures, it is reported.
The investigation will be carried out by the National Institute of Clinical Excellence (Nice).
About 10m Britons are believed to be following a diet at any one time, a third of them choosing Atkins-style, high-protein regimes.
Three-quarters of adults in the UK are reportedly overweight or obese.
The Atkins diet involves eating unrestricted amounts meat and other high protein food while restricting carbohydrates
The team that will evaluate it will be made up of up to 20 doctors, nutritionists and dieticians, the Independent on Sunday reports.
Unhealthy?
Critics of the Atkins diet claim it can have consequences such as kidney damage, thin bones and high cholesterol.
The potential long-term consequences of high-fat diets are still unknown, they warn, and are likely to include a higher risk of diabetes and early heart attack.
A recent study warned that the diet might also reduce woman's chances of conceiving.
But the diet, which leads to rapid weight loss, has been praised by scores of celebrities, including singer Robbie Williams and actress Jennifer Aniston, and has proved hugely popular with the public.
The Atkins company, which has launched a special food range to go with its diet books, has a turnover of about �60m.
Obesity 'epidemics'
Its biggest markets are the USA, Britain, Japan and Italy.
The investigation into the Atkins diet is part of the most comprehensive study of obesity in Britain so far.
It will be carried out by Nice, a regulatory body which provides national guidance on treatments and care in England and Wales, together with the Health Development Agency.
The inquiry comes in the wake of a damning report from the Commons Select Committee on Health, which criticised ministers for failing to tackle growing obesity rates.
The results of the study, which will be published in a year's time, is expected to have an impact on how doctors choose to treat their overweight patients.