An estimated 3 million people in the UK have tried cutting their carbohydrate intake to comply with the diet, not to mention the many more millions in the US where the diet started.
But researchers at the Aberdeen-based Rowett Research Institute say they want to understand the mechanism behind high-protein, low-carbohydrate weight-loss diets because despite widespread use and many anecdotal reports, there is a lack of scientifically proven reasons why thisparticular regime works.
"We want to find out what it is that makes this type of diet easy to stick to, because that is obviously an important part of why people find it an effective way to lose weight," said Dr AlexJohnstone, an expert in weight loss studies who will lead the project.
"Is it the high protein content of the diet which helps to satisfy appetites, or is it anotherphysiological mechanism that is operating?" she added.
The researchers believe that better understanding of the underlying mechanisms of high-protein, low-carb diets could help them develop healthier, longer-term weight-reduction strategies.
Despite doubts about the science behind the regime, a quarter of the Europe or US-based food and drink companies recently interviewed by Reuters Business Insight said they are actively investing in the research and development of new low-carb products. The US market, worth around $15 billion this year, is forecast to double by 2005.
This is being driven by surging numbers of obese. Obesity and overweight are at epidemic proportions in the UK, with some 68 per cent of males and 57 per cent of females collectively overweight and obese, according to the chief scientist's report in 2002.
And this has prompted government funding for new studies, such as the one being carried out by Rowett, for which the Scottish Executive is providing £900,000 over three years.
The researchers will recruit non-smoking obese men aged between 20-55 years and in good general health, and examine a range of factors including food intake, quality of life, state of health, physical activity and fatigue.