The controversial high-protein, low-carbohydrate Atkins diet is a mass experiment into public health based on “pseudo science”, a leading British nutritionist has said.
Extreme “faddy” diets that cut out entire food groups were unbalanced, untested and could pose serious health problems, she warned.
It would be negligent to recommend the Atkins diet to anyone who was overweight, said Dr Susan Jebb, of the Medical Research Council Human Nutrition Research Centre, Cambridge.
Despite being derided by nutritionists for three decades, the Atkins diet has recently surged in popularity. Dr Atkins’ books outsell other non-fiction titles by three to one, while the diet has been endorsed by actresses Renee Zellweger, Minnie Driver, Jennifer Aniston and Catherine Zeta Jones and singer Geri Halliwell.
Atkins disciples are allowed unlimited proteins and fat but have to cut out carbohydrates such as bread, pasta and rice.
Dr Robert Atkins, who developed the diet in the 1960s, claimed that carbohydrates overstimulate insulin production, triggering hunger and weight gain. But Dr Jebb said the diet worked only because it reduced calorie intake. Staying on it could be harmful in the long term.
Nutritionists are concerned that eating lots of protein could strain the kidneys and increase amounts of calcium excreted from the body, affecting bone growth and regeneration.
Studies have shown that people who eat most carbohydrates have less heart disease and that fibre found in carbohydrates may reduce bad cholesterol and reduce cancer risk, Dr Jebb said.
Carbohydrates were also the source of essential vitamins and plant nutrients. Eating too much fat could double a woman’s risk of breast cancer.
Dr Jane Ogden, from King’s College, who joined Dr Jebb at a briefing at the Royal Institution, London, said most benefits of the Atkins diet were in the mind. Its simple, clear rules, smattering of pseudo science and the fact that it permitted tasty, high-fat food made it popular. But while the diet could be effective in the short term, like all diets it was usually doomed to failure, she said.
The moment the body starts losing weight, it lowers the metabolic rate to make it harder to shed further pounds. With any diet, about 60 per cent of people lose weight in the first few weeks but over the next few years 95 to 99 per cent regain all the weight they lose, and many put on even more.
“The reality of dieting is that you have to modify the behaviour that you have learned from being a baby, and that’s extremely difficult,” Dr Ogden said