Objective The effect of providing antenatal dietary and lifestyle advice on secondary measures of maternal anthropometry was evaluated and their correlation with both gestational weight gain and infant birth weight was assessed. Methods In a multicenter, randomized controlled trial, pregnant women with BMI of ≥25 kg/m2 received either Lifestyle Advice or Standard Care. Maternal anthropometric outcomes included arm circumference, biceps, triceps, and subscapular skinfold thickness measurements (SFTM), percentage body fat (BF), gestational weight gain, and infant birth weight. The intention to treat principles were utilized by the analyses. Results The measurements were obtained from 807 (74.7%) women in the Lifestyle Advice Group and 775 (72.3%) women in the Standard Care Group. There were no statistically significant differences identified between the treatment groups with regards to arm circumference, biceps, triceps, and subscapular SFTM, or percentage BF at 36-week gestation. Maternal anthropometric measurements were not significantly correlated with either gestational weight gain or infant birth weight. Conclusions Among pregnant women with a BMI of ≥25 kg/m2, maternal SFTM were not modified by an antenatal dietary and lifestyle intervention. Furthermore, maternal SFTM correlate poorly with both gestational weight gain and infant birth weight.