Birthweight, lifetime obesity and physical functioning in mid-adulthood: a nationwide birth cohort study

Area of Science:

• Life-course epidemiology
• Public health
• Human physiology

Background:

• Limited evidence exists on the long-term effects of childhood obesity and body mass index (BMI) changes on physical functioning (PF) over a lifetime.
• Understanding these associations is vital for developing effective public health strategies.
• The study investigates the impact of BMI trajectories and obesity onset on PF in later life.

Purpose of the Study:

• To determine if birthweight and BMI across the life-course are associated with physical functioning (PF) at age 50.
• To examine whether BMI gains at specific life stages are linked to PF at age 50.
• To assess if the age of obesity onset influences PF at age 50.

Main Methods:

• Utilized data from the 1958 British birth cohort (n=8674).
• Calculated body mass index (BMI) using measured and self-reported height and weight at various ages.
• Assessed physical functioning (PF) at age 50 using the Short-form 36 survey's PF subscale; logistic regression adjusted for covariates was employed.

Main Results:

• Obesity at any adult age was significantly associated with poorer physical functioning (PF) at age 50.
• Increases in BMI during adulthood, particularly between ages 16-23 and 45-50, were linked to diminished PF.
• Earlier onset of obesity, especially in childhood, showed a stronger association with poor PF in mid-adulthood compared to later onset or never being obese.

Conclusions:

• Obesity, significant BMI gains, and early-onset obesity are associated with reduced physical functioning in mid-adulthood.
• These findings underscore the critical importance of preventing obesity and delaying its onset to preserve physical function throughout life.
• Interventions targeting weight management from childhood are essential for long-term physical well-being.