Diet and exercise weight-loss trial in lactating overweight and obese women.

BACKGROUND Current evidence suggests a combined treatment of postpartum weight loss of diet and exercise. However, to our knowledge, neither their separate and interactive effects nor long-term outcomes have been evaluated. OBJECTIVE We evaluated whether a 12-wk dietary behavior modification (D) treatment to decrease energy intake, physical exercise behavior modification (E) treatment to implement moderate aerobic exercise, or combined dietary and physical exercise behavior modification (DE) treatment compared with control (usual care) (C) reduces body weight in lactating women measured at the end of treatment and at a 1-y follow-up 9 mo after treatment termination. DESIGN At 10-14 wk postpartum, 68 lactating Swedish women with a prepregnancy BMI (in kg/m²) of 25-35 were randomly assigned to D, E, DE, or C groups. Measurements were made at baseline, after the intervention, and again at a 1-y follow-up 9 mo later. A 2 × 2 factorial approach was used to analyze main and interaction effects of treatments. RESULTS Weight changes after the intervention and 1-y follow-up were -8.3 ± 4.2 and -10.2 ± 5.7 kg, respectively, in the D group; -2.4 ± 3.2 and -2.7 ± 5.9 kg, respectively, in the E group; -6.9 ± 3.0 and -7.3 ± 6.3 kg, respectively, in the DE group; and -0.8 ± 3.0 and -0.9 ± 6.6 kg, respectively, in the C group. The main effects of D treatment, but not of E treatment, on weight were significant at both times (P < 0.001). CONCLUSIONS Dietary treatment provided clinically relevant weight loss in lactating postpartum women, which was sustained at 9 mo after treatment. The combined treatment did not yield significant weight or body-composition changes beyond those of dietary treatment alone.