Relationship of dietary factors and physical activity to body fat in 3–5 year old children
The aims of the study were to (1) examine associations between environmental factors and percent body fat (PBF), and (2) determine if air-displacement plethysmography (ADP) and dual-energy x-ray absorptiometry (DXA) were accurate methods for assessing body fat in children 3 to 5 years old as compared to deuterium dilution (2H). Data including PBF, diet during infancy, 3-day food records, and the Netherlands Physical Activity Questionnaire (NPAQ) were collected from 78 children. Pearson's correlation analyses showed a significant, positive relationship between PBF and Healthy Eating Index (HEI) scores, r (36) = .332, p < .05, and a significant, negative relationship between PBF and NPAQ scores, r (36) = −.441, p < .01, in male participants. Repeated measures multi-variate analysis of variance showed main effects for gender and body fat methods were significant, F (1, 74) = 17.432, p < .0001, partial eta squared = .191 and F (2, 148) = 42.892, p < .0001, partial eta squared = .367, respectively. Main effect for feeding group was not significant, F (1, 74) = .553, p = .460, partial eta squared = .007. Mean PBF measured by DXA ( M = 27.531, SD = 5.674) was significantly different from mean PBF measured by 2H (M = 22.712, SD = 4.539) and ADP (M = 21.419, SD = 7.829). Correlation between 2H and ADP was moderate ( r = .461, p < .01). The results show obesity prevention should emphasize increased PA. The data failed to show breastfeeding influenced adiposity in young children. ADP may be an acceptable method when determining average PBF values in groups of children. However, the moderate correlation between ADP and 2H shows that ADP needs additional adjustments before it can be used effectively in individual assessments. Evidence was provided that DXA overestimates PBF in children by approximately 5–6%. This overestimation was fairly consistent. Therefore, DXA may be useful in a clinical setting to monitor PBF of children as long as the absolute value obtained is not crucial.