What was once a subject of public health debate is now a matter of clear scientific consensus: low-carb diets can be safe, nutritious, and should be included as an option within the Dietary Guidelines for Americans. A group of experts, including leading nutrition and health researchers and healthcare professionals, reviewed the evidence and arrived at more than 15 areas of unanimous scientific agreement on the benefits, opportunities and considerations around lower carbohydrate dietary patterns.

A review of the state of science and summary of the consensus statements are now published in the peer-reviewed journal Frontiers in Nutrition. Importantly, the experts agreed on a consensus definition of low-carbohydrate diets as those containing 50 – 129 gram of carbohydrates per day. Until now, no standard definition existed.

The established range of 50-129 grams of carbohydrates per day is lower than the current dietary reference intake (DRI), which recommends 45-65% of daily calories come from carbohydrates. Based on a 2,000-calorie diet, consuming 50-129 grams of carbohydrate per day would provide about 10-26% of daily calories. The scientific basis for DRI for carbohydrates is currently being reevaluated to take more recent research into account.

"This is a milestone achievement for the public health and scientific communities," said lead author Jeff Volek, PhD, The Ohio State University. "Now that we have a clear definition of what constitutes a low-carb diet, and a shared agreement on the evidence-based benefits of a low-carb diet, this information should be included in dietary recommendations and accessible to the broader public."

Other key takeaways about low-carb diets

The experts also agreed on several other important points.

• Low-carb diets are safe for the general public, though initial medical supervision may be necessary for some people, like those living with more medically complex conditions or taking certain medications.
• Low-carb diets are helpful for addressing insulin resistance within the general population and in those with or at risk of diet-related diseases, like obesity, type 2 diabetes, heart disease, and more.
• Well-planned low-carb diets can provide adequate nutrition and support high-quality diets similar to the healthy eating patterns currently recommended in the Dietary Guidelines for Americans.
• Including guidance around a healthy, lower-carb eating pattern within the Dietary Guidelines could help address health disparities and advance health equity.

"We've reached a critical mass of scientific evidence at this point," said Volek. "And nutrition experts now agree, low-carb diets provide benefits beyond disease management. In other words, they've been shown to not only help people with diet-related diseases, like heart disease and type 2 diabetes, they can also help generally healthy people reduce their risk of developing those diseases in the first place."

Federal agencies reevaluating scientific basis for low-carb diet

The newly published consensus statements come at a time when the U.S. Departments of Agriculture and Health and Human Services are considering potential changes to the Dietary Guidelines for Americans, with particular emphasis on the importance of health equity. The Dietary Guidelines for Americans provide a set of evidence-based nutrition recommendations that broadly inform public health and nutrition activities, including food and nutrition labeling, federal nutrition assistance programs, and education initiatives, all of which are foundational to addressing persistent health disparities in America.

Today's body of research suggests that lower-carb diets can have a beneficial effect on weight, insulin sensitivity, and heart disease risk – diseases that disproportionately affect people from historically marginalized backgrounds, like Black and Hispanic Americans – and the expert group agreed the inclusion of a lower-carbohydrate eating pattern in the Dietary Guidelines could enhance health equity across the country.

Volek added, "If we really want to make sure federal nutrition guidance is keeping up with the science and serving America's diverse populations with different health needs, priorities and preferences, then the Dietary Guidelines should be updated to include a lower-carbohydrate approach to eating."

This research was funded by an unrestricted educational grant from SIMPLY GOOD FOODS. SIMPLY GOOD FOODS was not involved in the writing or submission of the final manuscript.

The article, "Expert consensus on nutrition and lower-carbohydrate diets: An evidence- and equity-based approach to dietary guidance," is published in Frontiers in Nutrition. (doi.org/10.3389/fnut.2024.1376098)