Fig. 1

Adjusted* associations of total lifetime breastfeeding duration (quartiles) with average of dominant and nondominant handgrip strength (kg). *Adjusted for race/ethnicity, education, marital status, ever smoker, household income at enrollment, age at 1st pregnancy, and age at handgrip strength (Model 3). Quartile (Q) of total lifetime breastfeeding duration [median, interquartile range (IQR) and range (min–max)]: Q1: 2 months (IQR: 0–5 months, range: 0–7 months), Q2: 12 months (IQR: 9.8–13 months, range 8–17 months), Q3: 24 months (IQR: 20–26 months, range 18–30 months), Q4: 42 months (IQR: 36–57 months, range 31–100 months), confidence interval (CI)