Changes in material body composition from month one to month six postpartum in 11 breastfeeding, exercising women
Creators: name: Kwasnicki, 
Publisher: name: University of British Columbia
Year: 2009

description: In vitro studies indicate that during lactation, lipolysis is significantly higher in the gluteo-femoral region compared to other periods in a woman's life. Additionally, there is a marked decrease in LPL activity in the femoral region during lactation (Rebuffe-Scrive, 1985). This suggests that fat is mobilized preferentially from the femoral region to be utilized for the production of milk. Animal studies clearly indicate that maternal fat, particularly gluteo-femoral fat, is utilized for the production of milk (Steingrimsdottir, 1980; Bergmann, 1994; Roberts, 1984). However, human studies present varying results (Quandt, 1983; Kramer, 1993; Dewey, 1993; Manning-Dalton, 1983; Naismith, 1973; Brewer, 1989). There is enough evidence, however, to suggest that there is a relationship between lactation and the reduction of gluteo-femoral fat. It is well-documented that exercise aids in the reduction of body fat and therefore, it is hypothesized that exercise during the lactating, postpartum period will have the effect of mobilizing fat, especially gluteo-femoral fat, more readily than during any other period in a woman's life and return a woman to her prepregnancy figure more quickly. The compounded effect of exercise and breastfeeding on improving maternal body composition may encourage more women to participate in both of these healthy activities, thus improving her and her infant's health. It was the purpose of this study to examine maternal body composition changes in 11 breastfeeding, exercising women from month one to month six postpartum. It was hypothesized that the breastfeeding, exercising women would experience a larger reduction in gluteo-femoral fat compared to abdominal fat and that they would return to their pre-pregnancy weight by six months postpartum. Body weight, girth, skinfold, DXA measurements (BMC, BMD, Total body fat, body fat %, LTM, regional fat distribution), caloric intake, infant feeding patterns, infant size measurements, and estimated V02max were studied in 11 breastfeeding exercising women from month one to month six postpartum. Significant differences were found in body weight, girths, skinfolds, DXA BMC, DXA BMD, DXA body fat %, DXA total body fat and V02max in the subjects from month one to month six postpartum. The skinfold, girth and DXA regional fat distribution measurements do not suggest a regionalized, specialized functioning of body fat for the purpose of milk production and instead, the results suggest a more generalized, proportional loss of body fat from the abdominals, legs and trunk. The subjects did not return to their pre-pregnancy weights by 6 month postpartum as expected. From the present study, we cannot conclude that breastfeeding, exercising women lose fat or weight any more quickly than breastfeeding, non-exercising or formula feeding, nonexercising subjects. Instead, a multifactorial theory to weight and fat control during the postpartum period is suggested. This study is significant because it suggests that women can exercise and breastfeed thus improving their MV02, their subsequent energy and stamina levels and their body composition without any detrimental effects to their infant and maternal milk production. This study also presents a very comprehensive analysis of body composition in this particular subject group including an examination of DXA values.