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 new recommendations from the National Lipid Association.
Based on a review of existing research, the scientific statement emphasizes 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 the “bad” cholesterol that can build up in blood vessels and lead to clots, known as low-density lipoprotein cholesterol (LDL-C).
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.
But after a year, weight loss with these diets is similar to what people can achieve with diets that allow more carbohydrates, according to the recommendations.
Extremely low-carb diets can also be harder to stick with over time, and may severely restrict nutrient-dense foods that offer cardiovascular benefits, the recommendations stress.
There doesn’t appear to be a meaningful difference between low-carb and other types of diets for other markers of cardiometabolic health like blood pressure.
“While some patients prefer a low-carbohydrate eating pattern, which may be reasonable for short periods of time, long-term compliance is challenging, and long-term benefits and risks are not fully understood, especially with ketogenic diets,” said Carol Kirkpatrick, the lead author of the recommendations and a researcher at Idaho State University in Pocatello.
With ketogenic diets, people typically eat very few carbs and consume a lot of fat, putting the body into a metabolic state known as ketosis. This can make the body more efficient at burning fat for energy and trigger reductions in blood sugar, previous research has found.
“Ideally, adopt a diet full of plants and whole foods that provides overall cardio-protective qualities: rich in whole grains, vegetables, fruits, nuts, and legumes; eliminate processed foods and trans fats; limit refined grains, saturated fats, red meat and added sugars,” Seidelmann, who wasn’t involved in the study, said by email.
“Adults that are interested in pursuing a very low or low carbohydrate diet for weight loss should consult with their clinician in order to weigh the risks and benefits of various diets and to share in the decision making process.”