The Study
The effect of body fatness on regional brain imaging markers and cognitive function in healthy elderly mediated by impaired glucose metabolism.
This study looked at a group of older people and found that those with more body fat tended to have slightly smaller brain areas linked to memory and scored a bit lower on memory tests. But it didn’t watch them over time to see if the fat came first or if the brain changes came first—it just took a snapshot. So we can’t say fat causes the brain to shrink, only that they’re often seen together.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When people carry extra body fat, their bodies sometimes have trouble using sugar for energy. This can hurt the brain, especially areas that help with memory.
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 — even small brain shrinkage in these areas was tied to measurable memory problems, like forgetting names or visual details, which matter in daily life.
- 2People with more body fat had smaller brain areas: frontal lobe shrank by β=-0.029, temporal lobe by β=-0.022, and hippocampus by β=-0.029.
- 3These changes were linked to worse memory scores.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of psychiatric research
Year
2021
Authors
W. Kim, Heeseon Jang, Yun-Tae Kim, Jaelim Cho, Jungwoo Sohn, Gayoung Seo, Jiae Lee, Sung-Hee Yang, Seung-Koo Lee, Y. Noh, S. Koh, S. Oh, Hee Jin Kim, S. Seo, H. Kim, Jung Il Lee, Sunyoung Kim, Changsoo Kim
Related Content
Claims (6)
In adults aged 50 and older without cognitive impairment, higher body fat is associated with smaller brain structures including the grey matter, frontal and temporal cortices, and hippocampus, and these reductions are linked to poorer glucose metabolism.
In cognitively healthy older adults, higher body fatness is linked to smaller brain volume in the frontal lobe, temporal lobe, and hippocampus, and this link occurs through impaired glucose metabolism.
In older adults without cognitive impairment, higher body fat is linked to higher insulin levels, reduced insulin sensitivity, shrinkage in specific brain regions, and worse memory performance.
In older adults without cognitive impairment, higher body fat is linked to poorer memory, and this link is partly due to smaller hippocampal volume and thinner frontal and temporal brain regions.
When the brain cannot use glucose properly due to disrupted insulin signaling, it receives less energy, leading to reduced cognitive function.
In older adults without cognitive impairment, thinner brain regions in the frontal and temporal lobes are linked to worse memory for visual information, and a smaller hippocampus is linked to worse memory for visual and verbal information.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.