While extremely low carbohydrate diets may aid short-term weight loss, they have mixed effects on health markers that can contribute to heart disease risk, according to recommendations from the National Lipid Association in the US.

Based on a review of existing research, the scientific statement emphasises some advantages of a ketogenic — or very low-carb — diet, including appetite suppression, lower lipid levels and lower blood sugar in people with diabetes.

But a keto diet is also associated with spikes in low-density lipoprotein cholesterol.

Over six months, people may lose more weight with popular low-carb diets like the Atkins, ketogenic, South Beach and Zone diets, according to the recommendations published in the Journal of Clinical Lipidology.