Associations Between Paternal Pre-Conceptional Body Mass Index and Lifestyle Factors and Offspring Weight Development.

BACKGROUND: Evidence suggests that pre-conceptional paternal factors, including BMI and diet, may influence offspring development. OBJECTIVES: We examined the associations between paternal BMI, dietary protein intake, glycemic index (GI), smoking and alcohol consumption and offspring development during the first 5 years of life. METHODS: This secondary analysis of an RCT included 162 father-child pairs from pregnancies among women with pre-pregnancy overweight or obesity. Paternal characteristics were reported at gestational week 15, reflecting the preceding 3 months. Offspring anthropometry was measured at birth, 6 and 18 months, 3 and 5 years. Associations were examined using linear mixed models and linear regression models. RESULTS: No consistent associations were found between paternal characteristics and offspring outcomes from birth to 3 years. At age 5, higher paternal BMI was associated with higher offspring BMI z-score (β = 0.07 (CI: 0.03; 0.10)), fat mass index (β = 0.07 kg/m2 (CI: 0.02; 0.12)) and fat-free mass index (β = 0.05 kg/m2 (CI: 0.01; 0.08)). Lower paternal protein intake was associated with higher offspring BMI z-score (β = 0.54 (CI: 0.07; 1.01)) and fat-free mass index (β = 0.60 kg/m2 (CI: 0.13; 1.07)), while moderately higher protein intake was associated with higher waist-to-height ratio (β = 0.03 (CI: 3.00 × 10-3; 0.05)). Higher paternal GI was associated with lower offspring BMI z-score (β = -0.04 (CI: -0.08; -2.14-10-3)) at age 5. Smoking and alcohol were not associated with offspring outcomes. CONCLUSION: Paternal BMI was associated with offspring outcomes at age 5 years, while findings for paternal dietary factors were less consistent.