Date of Award
Doctor of Philosophy
Naima Moustaid-Moussa, Michael Zemel, Dixie Lee Thompson, Priscilla Blanton
This study was designed to investigate the differences in the diets, activity levels, body concerns, body esteem, and body perceptions of fifty preadolescent boys in relation to their body mass index (BMI; kg/m2) and their percent body fat (PBF), measured using air-displacement plethysmography. Additionally, it was designed to examine general parenting and child feeding practices of parents in relation to their sons' BMI and PBF. Boys were recruited based on their BMI and were placed into either an average BMI group or a high BMI group. Additionally, boys were placed into either a lower PBF group or an upper PBF group. The results of this study were divided into three parts.
The first part examined the relationship between the BMI and PBF of the boys and evaluated whether boys grouped by their BMI status would be grouped similarly based on their PBF. PBF was significantly correlated with BMI (r=0.74, p<.0001) and the two ways of grouping boys were not independent (χ2=t3.52, p<.0001). Twelve of the 50 boys were classified differently into the BMI and PBF groups. Boys were recruited for the study based on their BMI, and boys whose BMI fell between the 68th and the 85th percentile were intentionally excluded from the study to allow for greater separation between groups of boys. It was anticipated that this separation in BMI would also provide a separation in PBF between groups. However, no clear separation in PBF between groups was evident. Therefore, results were mainly presented based on boys' BMI groups.
The second part examined whether differences existed in the diets, activity levels, body concerns, body esteem, and body perceptions of the boys by their BMI groups and examined if parents perceived their sons differently depending on their sons' BMI. No differences were found in the energy intakes or activity levels by boys' BMI groups. Boys in the high BMI group were more concerned about their weight and appearance as compared to boys in the average BMI group. Boys in the high BMI group perceived themselves as bigger than the boys in the average BMI group, and the same was true for their parents. Boys in the high BMI group rated their current figure as heavier than their ideal boy figure.
The third part examined differences in mothers' and fathers' child feeding practices and parenting practices by their sons' BMI groups. Mothers and fathers of boys with a high BMI saw their sons as more overweight, were more concerned about their weight, and used pressure to eat less often with their sons compared to mothers and fathers of boys with an average BMI. In addition, fathers of boys with a high BMI monitored their sons' eating less often than fathers of boys with an average BMI. When compared to fathers, mothers were more responsible for providing food to their sons. No differences were found in general parenting practices by boys' BMI. However, mothers were more likely to use the authoritative style of parenting compared to fathers.
Some overall conclusions may be drawn from this study. Classification of boys based on their BMI and PBF produced different groups of boys, indicating that BMI may be a useful screening tool, but it can be problematic when evaluating individual boys. Boys in the high BMI group perceived themselves to be heavier than boys in the average BMI group, and they were more concerned about their bodies compared to boys in the average BMI group. Finally, parents of boys with an average BMI tended to use more controlling child feeding practices with their sons compared to parents of boys with a high BMI.
Brann, Lynn Samson, "An Evaluation of Influences on Preadolescent Boys' Body Mass Index and Body Composition. " PhD diss., University of Tennessee, 2003.