The Study
Relationships between circulating 25(OH) vitamin D, leptin levels and visceral adipose tissue volume: results from a 1-year lifestyle intervention program in men with visceral obesity
This study found that when men lost belly fat and their vitamin D went up, their leptin levels went down — but it didn’t prove that vitamin D caused the leptin change. It just showed they moved together, like two kids on a seesaw.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
When men lost belly fat by eating less and moving more, their body fat signal (leptin) went down and their vitamin D went up—even though they didn’t take supplements.
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 542 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this suggests losing fat may naturally improve two key signals for hunger and metabolism, even without supplements.
- 2Belly fat dropped 26%, leptin dropped 27%, vitamin D rose 27%.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
International Journal of Obesity
Year
2020
Authors
Anne Gangloff, Jean Bergeron, Isabelle Lemieux, Angelo Tremblay, Paul Poirier, Natalie Alméras, Jean-Pierre Després
Related Content
Claims (5)
Men who had excess belly fat saw their vitamin D levels go up by 27% after a year of eating better and moving more—even though they didn’t take any vitamin D pills or supplements.
If overweight men lose a lot of belly fat over a year by eating better and moving more, their hunger hormone (leptin) goes down and their vitamin D levels go up — both by about a quarter.
When overweight men lose body fat through lifestyle changes like diet and exercise over a year, their vitamin D levels go up by about 27% and their leptin (a hunger hormone) levels drop by 27%—and these two changes seem to be connected, even after accounting for how much fat they lost in different parts of their body.
In men who carry extra fat around their belly, when their vitamin D levels go up or down, their leptin levels (a hormone that affects hunger) also change — even when you account for how much fat they have in different parts of their body.
If a man with excess belly fat eats less and moves more for a year, his belly fat, hunger hormone levels, and vitamin D levels all get better.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.