To describe breastfeeding rates from early to late infancy and to examine associations between breastfeeding duration and infant growth, including rapid weight gain (RWG, > 0·67 SD increase in weight-for-age Z-score), among infants from low-income, racially and ethnically diverse backgrounds.

A short, prospective cohort study was conducted assessing breastfeeding status at infant ages 2, 4, 6, 9 and 12 months. Infant length and weight measurements were retrieved from electronic health records to calculate weight-for-length Z-scores and the rate of weight gain.

Pediatric clinic in the Southeastern USA.

Mother-infant dyads (n = 256).

Most participants were African American (48 %) or Latina (34 %). Eighty-one per cent were participating in the Special Supplemental Nutrition Program for Women, Infants and Children. Infants were breastfed for a median duration of 4·75 months, with partial more common than exclusive breastfeeding. At 12 months, 28 % of the participants were breastfeeding. Infants breastfed beyond 6 months had significantly lower growth trajectories than infants breastfed for 0–2 months (β = 0·045, se = 0·013, P = 0·001) or 3–6 months (β = 0·054, se = 0·016, P = 0·001). Thirty-six per cent of the infants experienced RWG. RWG was more common among infants who were breastfed for 2 months or less than 6+ month breastfed group (relative risk = 1·68, CI95 (1·03, 2·74), P = 0·03).

Breastfeeding beyond 6 months is associated with the prevention of accelerated growth among infants from low-income, racially and ethnically diverse backgrounds, suggesting progress toward health equity.

To explore patterns of post-malnutrition growth (PMGr) during and after treatment for severe malnutrition and describe associations with survival and non-communicable disease (NCD) risk 7 years post-treatment.

Six indicators of PMGr were derived based on a variety of timepoints, weight, weight-for-age z-score and height-for-age z-score (HAZ). Three categorisation methods included no categorisation, quintiles and latent class analysis (LCA). Associations with mortality risk and seven NCD indicators were analysed.

Secondary data from Blantyre, Malawi between 2006 and 2014.

A cohort of 1024 children treated for severe malnutrition (weight-for-length z-score < 70 % median and/or MUAC (mid-upper arm circumference) < 110 mm and/or bilateral oedema) at ages 5–168 months.

Faster weight gain during treatment (g/d) and after treatment (g/kg/day) was associated with lower risk of death (adjusted OR 0·99, 95 % CI 0·99, 1·00; and adjusted OR 0·91, 95 % CI 0·87, 0·94, respectively). In survivors (mean age 9 years), it was associated with greater hand grip strength (0·02, 95 % CI 0·00, 0·03) and larger HAZ (6·62, 95 % CI 1·31, 11·9), both indicators of better health. However, faster weight gain was also associated with increased waist:hip ratio (0·02, 95 % CI 0·01, 0·03), an indicator of later-life NCD risk. The clearest patterns of association were seen when defining PMGr based on weight gain in g/d during treatment and using the LCA method to describe growth patterns. Weight deficit at admission was a major confounder.

A complex pattern of benefits and risks is associated with faster PMGr. Both initial weight deficit and rate of weight gain have important implications for future health.

To assess relationships between breast-feeding, rapid growth in the first year of life and overweight/obesity status at the age of 2 years.

As part of an observational, longitudinal study beginning in early pregnancy, multivariable logistic regressions were used to assess associations between breast-feeding duration (total and exclusive) and rapid weight gain (RWG) between birth and 1 year of age, and to determine predictors of overweight/obesity status at the age of 2 years.

Nine hospitals located in the province of Quebec, Canada.

A sample of 1599 term infants who participated in the 3D Cohort Study.

Children having RWG in the first year and those having excess weight at the age of 2 years accounted for 28 % and < 10 %, respectively. In multivariable models, children breastfed < 6 months and from 6 months to < 1 year were, respectively, 2·5 times (OR 2·45; 95 % CI 1·76, 3·41) and 1·8 times (OR 1·78; 95 % CI 1·29, 2·45) more likely to show RWG up to 1 year of age compared to children breastfed ≥ 1 year. Children exclusively breastfed < 3 months had significantly greater odds of RWG in the first year (OR 1·94; 95 % CI 1·25, 3·04) compared to children exclusively breastfed for ≥ 6 months. Associations between breast-feeding duration (total or exclusive) and excess weight at the age of 2 years were not detected. RWG in the first year was found to be the main predictor of excess weight at the age of 2 years (OR 6·98; 95 % CI 4·35, 11·47).

The potential beneficial effects of breast-feeding on rate of growth in the first year of life suggest that interventions promoting breast-feeding are relevant for obesity prevention early in life.