Does Breastfeeding Protect Against Childhood Obesity母乳喂养对儿童肥胖的保护.ppt

Summary of BF obesity studies 17 of the 21 studies showed an association between breastfeeding and a lower risk of obesity All of the studies that took into account the exclusivity of BF showed a significant association 13 of the 16 studies that controlled for maternal BMI showed a significant association In meta-analysis, duration of BF showed a dose-response relationship with risk of child obesity. Lowest risk was for 6 mo of BF Explanations? Not solely due to lower fatness during first 2 y Potential mechanisms include: Learned self-regulation of energy intake Metabolic programming due to differences in milk composition, protein intake, fatness and/or rate of weight gain in early life Residual confounding, e.g. by child feeding practices, physical activity Clinical public health implications Provides further evidence to promote breastfeeding However, role of breastfeeding is probably small compared to other factors such as parental overweight, dietary practices and physical activity Relationship less evident in African-Americans and Hispanics – not clear why Breastfeeding and risk of child obesity Kathryn G. Dewey, PhD Program in International and Community Nutrition University of California, Davis Study selection criteria N 100 per feeding group Age at follow-up 3 y Outcome = % overweight or obese Studies in preschool children Author, year, site N, age Feeding groups Outcomes Results [*p 0.05] Armstrong, 2002, Scotland 32,200 3-4 y EBF vs. EFF at 6-8 wk BMI 95th BMI 98th AOR 0.72* AOR 0.70* Bogen, 2004, USA1 73,458 4 y BF 8 wk, 8-15 wk, 16-26 wk, 26 wk (+/- concurrent FF) BMI 95th AOR 0.71 for 16-26 wk w/o FF* Hediger, 2001, USA 2,685 3-5 y Ever BF vs. EFF (+ dur. full BF) BMI 85-94th BMI 95th AOR 0.63* AOR 0.84 Grummer-Strawn, 2004, USA 177,304 (12,587) 4 y BF 1, 1-3, 3-6, 6-12, or 12 mo, vs. EFF BMI 95th AOR for White, non-Hisp 0.70* (6-12 mo) 0.49* ( 12 mo) O’Callaghan, 1997, Australia 3,909 5 y BF duration BMI 85-94th BMI 95th NS Burke, 20