Weight loss advice in the U.S. has long centered on calorie targets, food logs and points systems. A newly published clinical trial from North Carolina instead tested whether people could lose weight by following a Mediterranean-style eating pattern that emphasized food quality rather than calorie counting. The results, published August 20 in JAMA Network Open, found participants in that program did lose weight, but not more than people assigned to a conventional weight loss program.
A randomized trial tested weight loss without calorie counting
The study was the Delicious Eating for Life in Southern Homes, or DELISH, randomized clinical trial, conducted in central North Carolina and published August 20 by JAMA Network Open. According to the journal, researchers enrolled 360 adults with obesity from one academic and six community primary care practices and randomly assigned 182 to the Mediterranean-style program and 178 to a control weight loss program. The Mediterranean-style intervention was designed in phases, beginning with diet quality improvements before shifting to weight loss and then maintenance, the study reported.
Researchers said the Mediterranean-style plan emphasized higher-quality fats and carbohydrates, including foods such as vegetable oils, nuts, seeds, fish, whole grains, fruits and nonstarchy vegetables, while reducing refined carbohydrates and processed foods. The control group received WW, the commercial program formerly known as WeightWatchers, according to the study. At 24 months, the journal said there was no material difference in percentage weight change between the two groups.
That means the headline finding is narrower than some broad online summaries may suggest: participants in the Mediterranean-style group did lose weight, but the approach did not clearly beat the comparison program on the trial’s primary outcome. Still, the study adds to evidence that structured weight loss can occur without traditional calorie counting when participants receive an intensive behavioral program centered on food patterns and counseling, according to the article.
The clearest local connection is central North Carolina
The local footprint of the study is specific: DELISH recruited participants from primary care practices in central North Carolina, according to the trial report. The journal did not publicly identify every participating clinic in the main article text available online, but it confirmed the research drew patients from one academic practice and six community practices in that region. That makes North Carolina, rather than a single city, the most clearly verified geography tied to the findings.
What is confirmed is that the trial population came from routine health care settings rather than a tightly controlled laboratory environment. Researchers used electronic health records at those facilities to identify eligible adults ages 18 to 75 with a body mass index of 30 or higher, according to the paper. Enrollment ran from June 12, 2020, through May 11, 2022, with final follow-up data collected June 16, 2024.
What is not yet known from the public report is a full city-by-city breakdown of where participants lived or whether outcomes differed across individual North Carolina communities. The published article also does not provide a comprehensive public list of all affected clinic locations in the main text. For readers in North Carolina, the practical takeaway is that this was a homegrown trial carried out in ordinary primary care settings, not an overseas or inpatient study.
Why researchers studied this approach and what it means now
Researchers said they launched the trial because Mediterranean-style eating is already associated with lower chronic disease risk, but has been understudied in U.S. weight loss interventions. The article noted that intensive weight loss programs can improve cardiovascular risk factors and diabetes incidence, while some large long-term trials have not shown reductions in cardiovascular events or mortality. That background helped frame the question of whether improving diet quality could support meaningful weight loss and broader health gains.
The study’s authors also argued that many standard programs focus heavily on energy restriction, while a Mediterranean-style pattern may better target obesity-related health risks by changing what people eat, not only how much. In the trial, that approach did improve diet quality, according to the journal. But on body weight itself, the Mediterranean-style strategy and the control program ended up producing similar long-term results.
For consumers, the findings do not show that calorie counting is unnecessary for every diet plan, and they do not show that Mediterranean-style eating outperformed established commercial weight loss support in this study. What the results do show is that adults in a structured behavioral program were able to lose weight while following a Mediterranean-style pattern that centered on healthier food choices rather than explicit calorie tracking, according to the published trial. The authors said that approach may still matter for long-term counseling as clinicians look for realistic ways to support weight management in primary care.