Abstract : For almost ten years, Mauritania has incorporated the WHO recommendations of exclusive breastfeeding (EBF) into the national breast-feeding promotion program. As the yet available information is based only on the biased survey model, there is a lack of objectively assessed breastfeeding practices information in Mauritania. Thus, in order to cope this problem the breastfeeding regime was determined using the dose-to-mother deuterium dilution technique Therefore, 90 couples from 4 communities located in the Wilaya of Gorgol (south of Mauritania) were divided into 2 nearly equivalent groups; the first one received an Awareness-Raising Intervention (ARI) during one year (IG group) and the second without any intervention (CG group). Even though there is some increase in EBF rate, the ARI intervention and the subsequent behavior changes seem to increase the percentage of overweight by 2.2%. This result is inconsistent with predicted lowering of mother weight in function of EBF rate. Remarkably, nearly the half of investigated mothers were over-weighted OW (51.1% and 48.9% for IG and CG group, respectively) and there is an important proportion of mothers exceeding the normal limit (35% of Fat mass), with the OW level of 63.6 and 68.3% for IG and CG group respectively, highlighting a lofty prevalence of obesity in the women population.