The Study
Effectiveness and metabolic impacts of restricting the consumption of ultra-processed foods in individuals with obesity submitted to energy restriction: a randomized clinical trial.
This study gave two groups of people different diets and saw who lost more weight. Because they randomly picked who got which diet, we can guess that the diet caused the difference in weight loss — but the difference was tiny. So it’s not a huge win, and we can’t say it works for everyone.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if telling people to eat less junk food helps them lose more weight when they're already eating fewer calories.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 556 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The extra weight loss was very small — less than 4 kg — and likely not meaningful for most people's health.
- 2People who tried to eat less junk food ate it 14% of the time (down from 21%) and lost a little more weight (82.9 kg vs.
- 386.3 kg) than those who just ate fewer calories.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrition, metabolism, and cardiovascular diseases : NMCD
Year
2025
Authors
M. Macena, M. R. Pereira, D. R. Silva, A. Silva-Júnior, A. D. Oliveira, J. V. L. Santos, D. Paula, Maria Bárbara Galdino-Silva, K.M.M. Almeida, D. C. Ferro, Guilherme César de Oliveira Carvalho, Marianna V.C. Rocha, Natália G.S. Lopes, R. Carnaúba, Samyra Araújo Monteiro Carvalho, Ana Gisbert Clemente, G. S. Bádue, Ingrid S.V. Melo, J. Barros-Neto, T. T. Florêncio, V. J. Martins, N. Bueno
Related Content
Claims (4)
Among obese adults on a calorie-restricted diet, lowering ultra-processed food consumption from 22% to 14% of total calories for one year led to an additional 3.4 kg of weight loss compared to those who kept ultra-processed foods at 20% of their diet.
Among obese adults on a calorie-restricted diet, a 12-month program that limited ultra-processed foods lowered their ultra-processed food consumption score from 2.74 to 1.86, while those without the program showed no significant change.
In a study of obese adults on a calorie-restricted diet, ultra-processed food intake started at about 22% and stayed above 20% throughout the year, meaning the participants did not consume high amounts of ultra-processed foods and may not represent people who do.
People who avoid ultra-processed foods lose twice as much weight in 8 weeks as people who eat ultra-processed foods.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.