In this study, we tested the effect of a 4-week Mediterranean meal plan, implemented at 5 months postpartum in women with obesity and demonstrated for the first time that the intervention improved maternal HEI scores and plasma lipid profiles, reduced maternal BMI and fat mass, decreased HM concentrations and infants’ intakes of leptin, TNF-α, LNFP II, LNFP-III, DFLNT, total HMOs and HMO-bound fucose. The gene discussed is TNF; the disease is obesity due to melanocortin 4 receptor deficiency.