Metabolic propensity toward obesity in black vs white females: responses during rest, exercise and recovery.
OBJECTIVE
To examine the existence of a metabolic propensity toward the development of obesity in black vs white females.


METHODS
Cross-sectional comparison of responses during 30 min of rest, 30 min of treadmill exercise at 65% VO2max, and 30 min of recovery.


METHODS
22 (11 black, 11 white) healthy, normal weight, sedentary females with a family history of obesity.


METHODS
Biometric measures (body mass index, waist-to-hip ratio, and body composition by hydrodensiometry) to insure inter-group homogeneity. Oxygen consumption (VO2), respiratory exchange ratio (RER), insulin, glucose and free fatty acids (FFA) during rest, exercise and recovery were measured to test for metabolic differences between the groups.


RESULTS
Black females displayed lower VO2 during rest (p = 0.04) and recovery (p = 0.04), higher RER during rest, exercise and recovery (p = 0.003), and higher levels of insulin (p = 0.03). No significant differences were observed for levels of blood glucose (p = 0.29) or serum FFA (p = 0.73).


CONCLUSIONS
Normal weight black and white females with comparable family histories of obesity exhibit dissimilar metabolic responses during rest, exercise and recovery. Lower rates of oxygen consumption, higher metabolic reliance on carbohydrate, and higher levels of insulin may slowly impact energy balance predisposing these black females toward the eventual onset of obesity.
Chitwood
L F
LF
Department of Exercise Science and Leisure Management, University of Mississippi, University 38677, USA.
Brown
S P
SP
Lundy
M J
MJ
Dupper
M A
MA
D000293:Adolescent; D000328:Adult; D044383:Black People; D001786:Blood Glucose / Q000378:metabolism; D003430:Cross-Sectional Studies; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D009765:Obesity / Q000503:physiopathology*; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange; D012146:Rest / Q000502:physiology*; D012307:Risk Factors; D044465:White People
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin