Is Atkins diet effective and are there risks?
Q - Is the Atkins diet effective and is there evidence of long-term risk?
A - Anecdotal reports from patients and a limited number of small clinical trials show people who follow the Atkins high-protein/low-carbohydrate diet regimen initially lose weight. There is no evidence that this is a specific consequence of the type of diet, rather it is a direct result of eating fewer calories.
At one year, weight loss is no different from that achieved with a conventional low fat, calorie-controlled diet plan. There is no data on weight change over periods greater than one year.
In clinical trials around a third of patients failed to complete the study, implying that adherence is poor. This is the critical issue for long-term weight loss and maintenance.
Evidence suggests a conventional low-fat/high-carbohydrate diet is linked to reductions in diabetes risk but no similar evidence exists for the Atkins diet.
The macronutrient composition of the Atkins diet is in direct contrast with international guidance recommendations for the reduction of chronic diseases, which emphasise decreases in fat, increases in unrefined carbohydrate, fruits and vegetables and no increase in protein.
The diet is nutritionally deficient in vitamins and minerals and patients should be advised to take supplements.
Theoretical risks include renal impairment and increased calcium excretion due to chronic high-protein consumption, together with increased risks of cancer and heart disease caused by the high-fat/low-carbohydrate content. Whether these risks materialise will depend in part on the extent of adherence to the programme.
There is insufficient evidence to recommend the Atkins plan to overweight patients. It is advisable to reduce the intake of refined carbohydrates, which often carry additional fat. Patients should be encouraged to include modest portions of unrefined carbohydrates, with plenty of fruits and vegetables (largely excluded on the Atkins diet) to retain the health benefits of these foods.
Susan Jebb is head of nutrition and health research at the
MRC Human Nutrition
Research Centre, Cambridge