Effects of familial predisposition to obesity on energy expenditure in multiethnic prepubertal girls.
BACKGROUND
The prevalence of childhood obesity is increasing and the causes of this are unknown.


OBJECTIVE
The objective of this study was to determine whether energy expenditure (EE), measured by 24-h calorimetry and doubly labeled water, differed in normal-weight-for-height, multiethnic prepubertal girls with or without a familial predisposition to obesity.


METHODS
Normal-weight, prepubertal white (n = 52), African American (n = 30), and Hispanic (n = 19) girls with a mean (+/-SD) age of 8.5 +/- 0.4 y were studied according to parental leanness and overweight or obesity. The girls were grouped according to whether they had 2 lean parents (n = 30), 2 obese parents (n = 27), or 1 lean and 1 obese parent (n = 44). Basal metabolic rate (BMR), sleeping metabolic rate (SMR), 24-h EE, respiratory quotient, heart rate, and activity were measured by 24-h room calorimetry; free-living total EE (TEE), activity-related EE (AEE), and physical activity level were measured by doubly labeled water. EE was standardized by fat-free mass (FFM).


RESULTS
There were no significant differences among familial groups in weight, height, fat mass, FFM, or percentage body fat. African American girls had a higher FFM than did white or Hispanic girls (P < 0.05). BMR, SMR, 24-h EE, respiratory quotient, heart rate, and activity levels were not significantly different among familial groups. Additionally, there were no significant familial group differences in TEE, AEE, or physical activity level. However, BMR, SMR, and TEE were lower in African American girls than in white girls (P < 0.05).


CONCLUSIONS
There was no significant difference in EE between normal-weight, multiethnic prepubertal girls predisposed to obesity and those not predisposed to obesity.
Treuth
M S
MS
US Department of Agriculture Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA. mtreuth@jhsph.edu
Butte
N F
NF
Wong
W W
WW
D001481:Basal Metabolism; D044383:Black People / Q000235:genetics; D015992:Body Mass Index; D002151:Calorimetry; D002648:Child; D004198:Disease Susceptibility; D002149:Energy Intake; D004734:Energy Metabolism / Q000235:genetics*; D005006:Ethnicity; D015444:Exercise; D005260:Female; D020022:Genetic Predisposition to Disease; D006630:Hispanic or Latino; D006801:Humans; D007553:Isotope Labeling; D008137:Longitudinal Studies; D009765:Obesity / Q000235:genetics*; D010101:Oxygen Consumption; D011627:Puberty; D014867:Water; D044465:White People / Q000235:genetics; D001741:Black or African American
D014867:Water