Obesity worsens and modest weight loss improves female fertility. Overweight women were randomised to lifestyle or standard treatment pre‐in vitro fertilisation with treatment cessation at embryo transfer. There was a greater reduction in weight (P < 0.001) for lifestyle treatment (−3.8 ± 3.0 kg, P < 0.001) compared with no changes for standard treatment (−0.5 ± 1.2 kg, P = 0.092). Both the intervention (−5.3 ± 4.6 cm) and control (−3.5 ± 3.5 cm) group had reductions in waist circumference (P < 0.001) with no differences between the two groups (P = 0.215). The overall pregnancy rate was 53% (20/38) for the intervention and control group combined.