• maternal concern about child weight;
  • obesity;
  • weight-discordant siblings



This study examined concern about child weight in mothers of weight-discordant siblings and determined the accuracy of maternal self-report versus measured child height, weight, and corresponding body mass index (BMI; kg/m2) z-score.

Design and Sample

Discordant sibling design. Forty-seven mothers of 5- to 12-year-old, weight-discordant siblings.


Mothers self-reported their concern about child weight for each child separately and for a subset of children, self-reported their heights and weights. Siblings' height, weight, waist circumference, and adiposity were measured.


The majority (83%) of mothers expressed concern about their overweight/obese child's weight and 20% of mothers expressed concern about their normal-weight child's weight (p < .001). Difference scores in maternal concern about child weight were positively associated with difference scores in sibling BMI z-score (r = 0.42; p = .01) and percent body fat (r = 0.56; p < .001). For overweight/obese children only, maternal-reported child heights and weights were significantly lower compared to the measured values (p < .03).


One fifth of mothers of weight-discordant siblings were unconcerned about their overweight/obese child's weight and for overweight/obese children only, mothers tended to underreport children's height and weight. Mothers' concern for their overweight/obese child's weight was greater for sibling pairs who were more discordant in their weight.