A new coalition of consumer, nutrition and public health groups has issued a warning that low-carb diets are unlikely to lead to sustained long term weight loss and can increase the risk of a number of life-threatening medical conditions.

At a news conference in Washington, members of the newly formed Partnership for Essential Nutrition announced the findings of a review of the scientific literature that it says will serve as the foundation for the activities and advocacy efforts of the coalition.

The review concluded that losing weight through low-carb diets could lead to serious health problems such as kidney stress, liver disorders and gout. Such diets could also increase the risk of coronary heart disease, diabetes, stroke and several types of cancer, the coalition said, adding that short-term effects of low-carb diets can include severe constipation, gastrointestinal problems, nausea, repeated headaches, difficulty in concentrating and loss of energy.

"Low carbohydrate diets conflict with decades of solid scientific research that clearly encourages us to reduce saturated fat and boost fruit, vegetable and fibre intake," said Barbara J. Moore, Ph.D., president and CEO of Shape Up America!, which founded the coalition. "Restricting carbohydrates stresses vital organs and alters brain metabolism while offering no advantages in terms of either fat loss or long-term weight control."

The Partnership for Essential Nutrition includes a number of non-profit consumer, nutrition and public health organisations, including the Alliance for Aging Research, American Association of Diabetes Educators, American Institute for Cancer Research, American Obesity Association and the National Consumers League.

The coalition also criticised the proliferation of competing food and beverage products now labelled as "low carb", "reduced carb", "carbohydrate free", "carb aware", "carb smart" and "carb countdown", none of which are regulated by the Food and Drug Administration (FDA).

The coalition called on the FDA to quickly issue an interim policy about the use of carbohydrate claims and then enforce it.