The Study
Urinary Sweeteners and Sugars in Relation to Childhood Obesity: The SWEET Project
This study looked at what sweeteners and sugars were in kids' pee and saw that kids with higher body weight tended to have more of certain sweeteners in their pee, and less sugar. But it didn't watch them over time, so we can't say the sweeteners made them gain weight — maybe kids who were already heavier chose sweeteners to eat less sugar.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Scientists measured chemicals in kids' pee to see what they ate. Kids with more diet soda sweeteners in their pee tended to have bigger waistlines and higher body weight, but kids with more natural sugar in their pee tended to have smaller waistlines — even though we usually think sugar makes you fat.
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 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — the effect sizes are large enough to suggest real differences in dietary patterns linked to body shape, even if we don't know if sweeteners cause weight gain or if heavier kids just choose more diet products.
- 2Kids with higher saccharin in pee had 51.59 higher BMI z-score units; those with higher sucralose had 291.29 higher BMI z-score units.
- 3Kids with more glucose or fructose in pee had lower BMI z-scores.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of Nutrition
Year
2025
Authors
Xinyi Cai, E. Brouwer-Brolsma, Gerben de Gier, N. Naomi, Jo Harrold, Jason C G Halford, A. Raben, M. Balvers, Edith JM Feskens
Related Content
Claims (6)
People who regularly consume low-calorie sweeteners tend to have more abdominal fat and larger waist measurements compared to those who do not.
People with higher levels of acesulfame in their urine tend to have lower BMI and waist-to-height ratio, and this is linked to eating more high-fiber foods and sports drinks instead of ultra-processed sweets.
In children and adolescents aged 8–17 years, higher levels of sugars in urine are linked to lower body mass index and waist-to-height ratio measurements.
In children and adolescents, higher levels of sucralose in urine are linked more closely to fat around the waist than to overall body weight measured by BMI.
Children and adolescents aged 8–17 with higher levels of saccharin and sucralose in their urine have higher body mass index and waist-to-height ratio measurements.
In children and adolescents, the amount of glucose excreted in urine is related to body fat levels in a non-linear way: those with moderate glucose excretion have lower body fat, while those with very low or very high glucose excretion have higher body fat.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.