| dc.description.abstract | Changes in energy expenditure in response to ingestion of a high protein, high fat meal versus an isocaloric high protein, low fat meal were investigated in 21 females, aged 19-28 years. Subjects were classified based on body mass index (BMI) as underweight (<18.5 kg/m2), normal weight (18.5-24.9 kg/m2), or overweight (? 25.0 kg/m2). Energy expenditure, measured using indirect calorimetry, was assessed before and every 30 minutes for 3.5 hours following consumption of the meals on two separate occasions. Height and weight were measured using standard techniques. Fat free mass (ffm) was measured using bioelectrical impedance analysis. No significant differences were found among the three groups in age, height, or fat free mass. BMI differed significantly
among the three groups, and body weight and body fat were significantly higher in overweight subjects versus normal weight and underweight subjects. Significant positive correlations were found between BMI and baseline metabolic rate (r2 = 0.29), between body weight and baseline metabolic rate (r2= 0.32), between BMI and average change in metabolic rate (r2 = 0.35), and between body weight and average total change in metabolic rate (r2= 0.22). Changes in metabolic rate (kcal/min) from baseline rate did not significantly differ in the underweight (n=3) subjects or in the overweight subjects (n=5) following consumption of either eal at any of the measured times. Changes in metabolic rate (kcal/min) from baseline rate were significantly higher in the normal weight subjects (n=11) at 2, 3, and 3.5 hours following the consumption of the high protein, high fat meal versus the high protein, low fat meal. Significant differences in metabolic rate were observed among the overweight, normal weight, and underweight subjects following consumption of both meals at most of the times measured. However, when metabolic rate was calculated as kcal/min/kg ffm or as change in metabolic rate from the baseline rate, no significant difference were found among the groups at any of the times. In conclusion, changes in metabolic rate in response to high protein, high fat versus high protein, low fat meals do not differ in overweight and in underweight subjects and thus, there is no metabolic advantage in diet-induced thermogenesis between the two meals. In contrast, in normal weight subjects, ingestion of a high protein, high fat meal significantly increased metabolic rate (69.3 kcal/3.5 hr) versus consumption of a high protein, low fat meal and provides a short-term metabolic advantage. | en_US |
