Lactation and weight retention

Abstract

The effect of lactation on weight retention was investigated longitudinally, with data collected at 0.5, 2, 4, 6, 12, and 18 mo after parturition in 110 women aged 20-40 y who had been nulliparous or primiparous. At each evaluation women were categorized as fully breast-feeding, partly breast-feeding, or bottle-feeding including infants weaned to a bottle (bottle feeding/weaned). Postpartum weight retention was calculated by subtracting weight before pregnancy from weight at each evaluation. Lactation practices were found to be significantly associated (P < 0.05) with postpartum weight retention by longitudinal regression analysis. Women who bottle-fed their infants retained more weight over time than women who breast-fed their infants. Significantly slower rates of weight loss were observed when women ceased breast-feeding or switched from fully to partly breast-feeding. Weight retention over time was greater in women who were older, unmarried, or had greater weight gain during pregnancy (P < 0.05). A pattern of weight gain rather than weight loss was observed in unmarried women. Our findings suggest that lactation influences the pattern of postpartum weight retention; however, the effect of lactation on weight retention was sufficiently limited to warrant minimal emphasis on lactation as a means of minimizing postpartum weight retention.

The association of pregnancy and the development of obesity – results of a systematic review and meta-analysis on the natural history of postpartum weight retention

“…Most studies included primarily adult women. 23,[27][28][29][31][32][33]35,36,38,43,46 Four studies reported a mean age above 30 years, 23,27,28,36,46 one study below 20 years. 42 Two studies did not provide any information on their population's age 24,44 (Table 1).…”

“…Tables 1-3 summarize the results of the qualitative analysis. Fifteen prospective studies, 23,24,[29][30][31][32][33][34][35][36]38,[40][41][42][43][44][45] five retrospective studies, 22,[25][26][27][28]37,46 and the control group from a randomized controlled trial 39 were included in the final analysis. Studies in which women were recruited around the time of delivery and then followed prospectively for postpartum body weight (ambivalent design, as baseline weight was assessed retrospectively) 24,29,30,[34][35][36][44][45][46] were considered as prospective in design, as we wanted to focus on the development of postpartum weight change.…”

“…The majority of studies were conducted in North America [22][23][24]29,35,[37][38][39][40]42,45,46 and Europe, [25][26][27][28]34,36,41,43 where the magnitude of weight retention among women appears to be similar. 39 In developing countries, women retain less weight after pregnancy compared with women in developed countries.…”

“…44 (Table 1) All but one 34 study were published in English language. [22][23][24][25][26][27][28][29][30][31][32][33][35][36][37][38][39][40][41][42][43][44][45][46] The study populations were mainly recruited from inpatients in departments of obstetrics. [24][25][26][31][32][33]35,36,[38][39][40][41][42][43][44][45][46] There was a higher percentage of low-income women in the studies conducted in North America, but socio-economic status was thought to be homogeneous across studies.…”

“…44 Ten studies preponderantly included white women. [25][26][27][28][29][30]34,36,38,40,41,43 Only one 36 of the European studies reported the ethnicity of their cohort. We assume that the women in the other European studies and in the Australian study were predominantly white.…”