Several studies have reported on associations of size at birth and early growth with general and central obesity; however, few have examined the potential effects of birth weight and postnatal growth on separate abdominal fat compartments. We investigated the effects of size at birth, linear growth and relative weight gain from birth to adulthood on visceral (VFT) and subcutaneous abdominal (SAFT) fat thicknesses at age 30 years. A total of 2663 participants from the 1982 Pelotas (Brazil) birth cohort study had complete information on ultrasound measures of abdominal fat at age 30 years, and anthropometric measurements for at least five visits (0/2/4/23/30 years). We estimated weight and height Z-score changes, conditional relative weight gain and conditional height at several ages. In both men and women, VFT and SAFT showed positive associations with conditional relative weight gain during all age periods beyond 2 years and birth, respectively (all P⩽0.01). Women born with intrauterine growth restriction (IUGR) had greater VFT than other women (difference=0.15 s.d., 95% CI: 0.01-0.29), and they showed a stronger positive influence of infant weight gain 0-2 years on VFT (IUGR: β=0.17 s.d., 95% CI: 0.05-0.29; non-IUGR: β=0.01 s.d., 95% CI: -0.04 to 0.06; Pinteraction=0.02). Stunting at 2 years was associated with lower SAFT but not VFT, and it modified the influence of weight gain 2-4 years on SAFT in both sexes (both Pinteraction<0.05). Our findings reinforce the advantages of being born with an appropriate birth weight, and the hazards of rapid postnatal gains in weight relative to linear growth, particularly after the critical window of the first 1000 days.