Individuals with overweight or obesity, as well as those who are underweight, are predisposed to limitations in activities of daily living (ADL), reveals a study.
A total of 25,212 articles describing associations between BMI and ADL impairment were identified following a search of six databases from inception through 12 August 2024. Of these, 132 met the eligibility criteria. [Eur J Clin Nutr 2026;80:449-457]
The investigators assessed study quality using the RoBANS tool. They also performed a random-effects meta-analysis, with BMI categories of <18.5 (underweight), 25–29.9 (overweight), and ≥30 kg/m2 (obese) as exposures, and 18.5–24.9 kg/m2 (normal) as the reference.
Positive associations were observed between BMI and ADL impairment in both longitudinal studies (odds ratio [OR], 1.77, 95 percent confidence interval [CI], 1.54‒2.03) and cross-sectional studies (OR, 1.56, 95 percent CI, 1.38‒1.76).
Overweight individuals showed a moderately increased ADL risk in longitudinal studies (OR, 1.19, 95 percent CI, 1.09‒1.30), but not in cross-sectional studies (OR, 1.06, 95 percent CI, 0.95‒1.18). On the other hand, underweight individuals were at increased risk of ADL impairment in both longitudinal (OR, 1.20, 95 percent CI, 1.02‒1.42) and cross-sectional studies (OR, 1.46, 95 percent CI, 1.24‒1.72).
“Our findings underline the importance of initiatives addressing both obesity and underweight status to mitigate the risk of ADL impairment,” the investigators said.
Mechanisms
Various mechanisms potentially influence the interaction between BMI and ADL impairment. For instance, a higher BMI often results in increased mechanical stress on weight-bearing joints, such as knees and hips, elevating the risk of osteoarthritis and reducing mobility. [BMJ Open 2015;5:e007568]
A low BMI, on the other hand, is associated with loss of muscle mass, which has been shown to have a positive association with dependence on ADLs. [BMJ Open 2015;5:e007568; J Cachexia Sarcopenia Muscle 2020;11:3-25]
One systematic review reported underweight and ADL as risk factors for sarcopenia, while another found an association between BMI and frailty. [Nutrients 2021;13:4291; Age Ageing 2021;50:1118-1128]
Specifically, underweight individuals were found be at increased risk of frailty (risk ratio [RR], 1.45, 95 percent CI, 1.10‒1.90), while those with overweight had a slightly reduced risk (RR, 0.93, 95 percent CI, 0.85‒1.02, and those with obesity had an elevated risk (RR, 1.40, 95 percent CI, 1.17‒1.67).
“In addition to our findings, other systematic reviews have examined BMI and disability, though with different focuses,” the investigators said.
“One review assessed BMI and the risk of disability retirement, reporting a higher risk among underweight (RR, 1.20, 95 percent CI, 1.02–1.41), overweight (RR, 1.13, 95 percent CI, 1.07–1.19), and obese individuals (RR, 1.52, 95 percent CI, 1.36–1.71) compared with normal-weight individuals, which aligns with our results,” they added. [Occup Environ Med 2020;77:48-55]
In another review focusing on BMI and ADL in older adults, underweight participants tended to have difficulties with basic ADLs (OR, 1.33, 95 percent CI, 1.03‒1.72), while those with overweight were less likely to face such difficulties (OR, 0.81, 95 percent CI ,0.79‒0.83). [BMC Public Health 2025;25:6]
“The focus of these reviews differed from ours,” the investigators said. “Our review expands on previous work by including both cross-sectional and longitudinal studies and by considering all adults aged ≥18 years.”