A recent press release from the Institute for the Advancement of Food and Nutrition Sciences (IAFNS), disclosed new research showing connections between heart and metabolic risk factors and low-carbohydrate diet patterns. With this data, it may lead to further discussion on the quality of carbohydrates.¹

The press release mentioned how researchers have become interested in learning more about how cardiometabolic health and carbohydrate quality may be involved with one another.

Tufts University (Medford, Massachusetts) researchers conducted the study, which was published in the Nutrition Journal, and “categorized low-carbohydrate diets into lower-quality or higher-quality carbohydrates based on their fiber content.”¹ As results came in, low-carbohydrate diets were found to be linked with larger increases in waist circumference. It did not matter if the quality of the carbohydrates was high or low. Additionally, positive changes were witnessed with systolic blood pressure.

Researchers gathered and analyzed data from 3,294 older adults that had participated in the Framingham Offspring Study, which is an observational study that takes place over the course of several years.¹ The median age of participants was 55 years old with 54% of participants being female.²

“Dietary intakes were assessed using the Harvard semi-quantitative food frequency questionnaire (FFQ), designed to capture the habitual dietary intake over the past 12 months. Participants received FFQs by mail with instructions to complete them at home and bring them to their exam appointments. Two different versions of FFQ were used to assess dietary intake: a 126 item FFQ used in exams 5 through 8 and an expanded 150 item FFQ used in exam 9. The food list included standard serving sizes and a selection of nine frequency categories ranging from “never or < 1 serving/month” to “≥ 6 servings/day,” the study mentioned.² “Dietary information was considered valid if reported energy intakes were > 600 kcal/day for both men and women; < 4,000 kcal/day for women; and < 4,200 kcal/day for men; and if ≤ 12 food items were left blank. Daily nutrient intakes were calculated by multiplying the frequency of intake of each food item by the nutrient content and summing across all food items. The reproducibility and validity of the FFQ have been evaluated for nutrients intakes for both men and women in other cohorts.

With blood cholesterol, “favorable changes” were seen with individuals that consumed high quality low-carbohydrate diets. When individuals consumed low quality carbohydrates on a low-carbohydrate diet, negative results were seen involving blood glucose levels. “It was not possible to differentiate low-carbohydrate diets by type of fat due to saturated and unsaturated fats being highly correlated,” the press release said.¹

“Our findings do not support low-carbohydrate diets broadly within the context of metabolic health, but if one is going to eat a low-carbohydrate diet, the research is indicating that eating fiber-containing carbohydrates is the better alternative,” noted senior author Paul Jacques, a senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.¹

Lead author, Ghaida F. Aloraini, who has conducted the work while being a graduate student at the Friedman School of Nutrition Science and Policy at Tufts University, said that, “Altogether, our findings support recommendations on preserving high-quality carbohydrates in the context of a lower carbohydrate diet and replacing low-quality carbohydrate with more healthy energy sources.”¹

“Our results suggest that, over long follow-up periods, LCD patterns that consider carbohydrate quality independently of fat and protein sources have mixed and relatively modest associations with CMRFs. Altogether, our findings support recommendations on preserving high-quality carbohydrates in the context of a lower carbohydrate diet and replacing low-quality carbohydrate with more healthy energy sources,” the study concluded.²

References

1. Quality of carbohydrates may be key to heart health https://www.newswise.com/articles/quality-of-carbohydrates-may-be-key-to-heart-health (accessed Oct 6, 2025).
2. Aloraini, G.F., McKeown, N.M., Rogers, G.T. et al. Impact of carbohydrate quality on the association between low-carbohydrate diet scores and longitudinal changes of cardiometabolic risk factors. Nutr J, 2025, 24, 127. https://doi.org/10.1186/s12937-025-01194-6