A comparison of Mediterranean-style and MyPyramid diets on weight loss and inflammatory biomarkers in postpartum breastfeeding women.

BACKGROUND: Of postpartum women, 15%-20% retain ≥ 5 kg of their gestational weight gain, increasing risk for adult weight gain. Postpartum women are also in a persistent elevated inflammatory state. Both factors could increase the risk of obesity-related chronic disease. We hypothesized that breastfeeding women randomized to a Mediterranean-style (MED) diet for 4 months would demonstrate significantly greater reductions in body weight, body fat, and inflammation than women randomized to the U.S. Department of Agriculture's (USDA) MyPyramid diet for Pregnancy and Breastfeeding (comparison diet).

METHODS: A randomized, controlled dietary intervention trial was conducted in 129 overweight (body mass index [BMI] 27.2 ± 4.9 kg/m(2)), mostly exclusively breastfeeding (73.6%) women who were a mean 17.5 weeks postpartum. Dietary change was assessed using a validated Food Frequency Questionnaire (FFQ) before and after intervention as well as plasma fatty acid measures (gas chromatography/flame ionization detector [GC/FID]). Anthropometric measurements and biomarkers of inflammation, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), also were assessed at baseline and 4 months via enzyme-linked immunosorbent assay (ELISA).

RESULTS: Participants in both diet groups demonstrated significant (p<0.001) reductions in body weight (-2.3 ± 3.4 kg and -3.1 ± 3.4 kg for the MED and comparison diets, respectively) and significant (p ≤ 0.002) reductions in all other anthropometric measurements; no significant between-group differences were shown as hypothesized. A significant decrease in TNF-α but not IL-6 was also demonstrated in both diet groups, with no significant between-group difference.

CONCLUSIONS: Both diets support the promotion of postpartum weight loss and reduction in inflammation (TNF-α) in breastfeeding women.