UNC Research Shows Mediterranean-Style Diet Enhances Weight Loss and Diet Quality

The study, named DELISH (Delicious Eating for Life in Southern Homes), examined a “Med-South” dietary pattern focusing on nuts, vegetable oils, whole grains, non-starchy vegetables, and fruits, tailored to regional food preferences. Findings were published in JAMA Network Open.

Co-principal investigators Thomas Keyserling, MD, MPH, and Carmen Samuel-Hodge, PhD, RD, who are affiliated with the UNC School of Medicine and the UNC Gillings School of Global Public Health respectively, spearheaded the research. The study aimed to assess whether the Med-South approach could yield sustained weight loss and enhance diet quality compared to conventional calorie-focused methods.

The research team enrolled 360 adults with a body mass index of 30 or higher from primary care practices in central North Carolina. Participants were randomly divided into two groups: one following the Med-South Weight Loss Program and a control group focusing primarily on caloric reduction.

Over the course of 24 months, the Med-South group participated in three phases: improving diet quality, focusing on weight loss while adhering to the Med-South eating pattern, and maintaining weight loss. Data on body weight, diet quality, blood pressure, and other health metrics were collected at four, 12, and 24 months. The Veggie Meter, which measures carotenoid levels in the skin—related to fruit and vegetable intake—was also used to assess diet quality.

Results indicated that both groups experienced weight loss, averaging about 4.5 kilograms, or 10 pounds, with no significant differences between them in weight loss or blood pressure reductions. However, participants in the Med-South group reported significant improvements in diet quality, including a higher intake of healthful fats, reduced carbohydrates, and better overall diet quality scores. Veggie Meter scores improved for participants in both groups.

Keyserling emphasized the importance of integrating a healthful dietary pattern into lifestyle weight loss programs, noting that while calorie-restricted diets can achieve similar weight loss, a healthful dietary approach offers additional benefits for chronic disease prevention. The study authors highlighted that residents of the Southeast face higher rates of chronic diseases like diabetes and cardiovascular issues, often linked to poor dietary habits. Previous research supports that diets prioritizing high-quality fats and carbohydrates lower cardiovascular disease risk more effectively than traditional low-fat diets.

Media Contact: Brittany Phillips, Communications Specialist, UNC Health | UNC School of Medicine.