Research

Hormonal

Aging significantly reduces sympathetic nervous system (SNS) drive to brown adipose tissue (BAT), leading to diminished metabolic BAT activity, whereas obesity alone does not impair SNS drive or metabolic activity.

If you are older, your body's natural signal to burn fat via brown fat (triggered by cold) is weaker than it was when you were young. This is not because you are obese, but because of age-related neural changes. Standard cold exposure might be less effective for you than for a young person, suggesting that interventions specifically targeting sympathetic nerve activity might be necessary to activate your brown fat.

ModerateQualifiesMEDIUM confidence
We found a lower SNS activity in the older men than in the lean young men, which may be the explanation for the lower metabolic BAT activity... A lower sympathetic drive may explain the lower BAT activity in the older men but not in the obese men.
Lonneke Bahler et al. · Journal of Nuclear Medicine · 2015

Why this rating

Observational study with small sample size (n=35) and specific demographic constraints (healthy men).

Source

Differences in Sympathetic Nervous Stimulation of Brown Adipose Tissue Between the Young and Old, and the Lean and Obese

Lonneke Bahler et al. · Journal of Nuclear Medicine · 2015

DOI 10.2967/jnumed.115.165829

cohort · n=35Cited 63×
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DOI resolved against Crossref · corpus check 2026-06-10

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