Research
Mixed
High cardiorespiratory fitness (CRF) attenuates or eliminates the mortality risk associated with high BMI, such that 'fit' obese individuals have lower mortality risk than 'unfit' normal-weight individuals.
If you have a high BMI, focus on improving your cardiorespiratory fitness through regular aerobic exercise. This can significantly reduce your mortality risk, potentially to levels lower than someone with a normal BMI who is physically unfit. Fitness is a vital sign.
StrongSupportsHIGH confidence
overweight and obesity in conjunction with moderate-to-high CRF (fit) were associated with a lower death rate than adults in the unfit normal-weight category.
Why this rating
Based on meta-analyses of multiple cohort studies.
Source
Obesity treatment: Weight loss versus increasing fitness and physical activity for reducing health risks
Glenn A. Gaesser et al. · iScience · 2021
DOI 10.1016/j.isci.2021.102995
narrative_reviewCited 149×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Increasing cardiorespiratory fitness (CRF) or physical activity (PA) consistently reduces all-cause and cardiovascular mortality risk, whereas intentional weight loss does not consistently reduce mortality risk and may increase it in healthy individuals.Strong
- Intentional weight loss is not consistently associated with reduced mortality risk and may increase mortality risk in healthy individuals.Good
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