The Study
Gut microbiota mediated the curvilinear association between dietary animal protein intake and bone mineral density in Chinese adults.
This study looked at what people ate and how strong their bones were, all at the same time. It found that people who ate more animal protein sometimes had stronger bones—but only up to a point. But we don’t know if the food caused the bone changes or if something else, like exercise or genetics, was responsible.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
This study looked at how eating different kinds of protein affects bone strength in Chinese adults, and whether gut bacteria play a role.
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
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.
- 1For an average adult, 0.87 g/kg/day is about 60–70g of protein daily — so both too little and too much animal protein may be bad for bones, and plant protein didn't help as much as expected.
- 2Eating less than 0.87 grams of animal protein per kg of body weight helped bones, but more hurt them.
- 3Plant protein was linked to weaker bones.
- 4Five types of gut bacteria explained about 15–19% of the animal protein effect.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Food & function
Year
2025
Authors
Yan-Jun Deng, Qiong Zhang, Mao-Xin Ren, Yun Zhang, Guang Li, Hao Feng, Xiaobao Wang, Yu-Hao Cui, Jia-Mei Huang, Xinlan Mao, Su-Mei Xiao
Related Content
Claims (6)
People who consume more dietary protein, including from animal sources, have higher bone mineral density.
In Chinese adults, the gut bacteria Lactococcus, Lactonifactor, Lachnoclostridium, Coprococcus_1, and Dialister account for 14.50% to 18.66% of the link between eating animal protein and bone mineral density at three bone sites.
In Chinese adults aged 18–64, consuming less than 0.87 grams of animal protein per kilogram of body weight per day is associated with higher bone mineral density, while consuming more than this amount is associated with lower bone mineral density.
In Chinese adults, bone mineral density is highest when animal protein intake is near 0.87 grams per kilogram of body weight per day. Intake significantly lower or higher than this level is associated with lower bone mineral density.
In Chinese adults aged 18–64, higher consumption of plant protein is linked to lower bone mineral density at the lumbar spine and total hip, with measurable reductions of 0.192 and 0.173 standard deviations, respectively, after accounting for animal protein intake.
In Chinese adults, higher consumption of plant-based proteins is linked to lower bone mineral density at the lumbar spine and total hip, even when accounting for animal protein intake.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.