Chitosan and weight
What 5 graded rows on chitosan agree on for weight, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the Chitosan page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the Chitosan page, with its PubMed record.
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Chitosan and weight
5 rows · 2,559 peopleMostly an improvement: 4 of 5 rows, and most of the people. 1 found no difference.
- CGrade C× 2
- DGrade D× 3
- Rows
- 5
- Trials
- 33
- People
- 2,559
- Pooled reviews may count some twice
Where they differ
From the rowsThe best-graded row, grade C, is a meta-analysis of 1,219 people (2008) and found an improvement.
The 4 rows that found an improvement were larger: a median of 613 people, against 34 people for the row that found no difference.
Only the 4 rows that found an improvement include pooled reviews of several trials (2 of 4); the row that found no difference is a single study.
Only the 4 rows that found an improvement name women in their population.
The 4 rows that found an improvement are newer (2008 to 2020) than the row that found no difference (1999).
The best grade is C among the rows that found an improvement, and D among the row that found no difference.
The rows
4 improved · 1 no difference- CGrade CBody weight, total cholesterol and blood pressure · Improved
Meta-analysis, 15 studies · n 1,219 · 2008 · Adults with overweight or obesity in 15 RCTs
Varied across trials · At least 4 weeks
Weight fell 1.7 kg and total cholesterol 0.2 mmol/L more than placebo, with lower blood pressure. Trials with proper allocation concealment, larger samples or longer duration showed substantially smaller effects. Adverse events did not differ from placebo.
- CGrade CBody weight, BMI and body fat · Improved
Meta-analysis, 15 studies · n 1,130 · 2020 · Adults in 15 RCTs (18 treatment arms)
Varied; effects clearer above 2.4 g/day · Varied; effects clearer under 12 weeks
Weight fell 0.89 kg, BMI 0.39 kg/m² and body fat 0.69% versus control.
- DGrade DBody weight and body composition · Improved
RCT · n 96 · 2016 · Adults with overweight or obesity, no diet change (India, multicentre)
500 mg capsules, 5 per day (2.5 g/day) · 90 days
The chitosan group lost a mean 1.78 kg by day 45 and 3.10 kg by day 90, significantly different from placebo (p<0.0001; the placebo change is not given in the abstract); body composition improved, lipids did not change and adverse events were mild.
- DGrade DBody weight and BMI · Improved
RCT · n 80 · 2014 · Women with overweight
3 g/day chitosan (plus 2 g/day vitamin C in one arm) · 8 weeks
Weight and BMI fell more than placebo in both chitosan groups, and adding vitamin C lowered BMI further (−1.6 vs −1.0 kg/m²).
- DGrade DBody mass index and blood lipids · No difference
RCT · n 34 · 1999 · Adults with overweight on their usual diet
4 capsules twice daily · 28 days
BMI, cholesterol, triglycerides and vitamins A, D, E and beta-carotene did not differ from placebo; vitamin K rose in the chitosan group.