THE BASAL METABOLISM RATE OF ADOLESCENT GIRLS IN THE SUB-TROPICAL AREAS OF CHINA / 营养学报

ABSTRACT

The basal metabolism of 126 healthy adolescent girls aged from 12-17 living in Guangzhou are carefully measured over Summer-Autumn and Winter seasons. Of these 126 subjects 32 were determined the BM during the menstrual cycles. The open indirect calorimetry method was employed. All expired gas were collected in Douglas bags. Gas samples were carried out by Beckmen OM-11 oxygen analyser and LB-2 carbon dioxide analyser. The BMR results are(1) The BMR of adolescent girls are gradually decreased as the index of secondary sexual appearance appeared. (2) When the energy expenditure expressed as kcal.kg-1.h~1, the difference of BMR is significantly at pre or post menarche. The BMR of pre-menarche is 8.3% higher than those of postmenarche. (3) BMR is influenced by menstrual cycles, shows a slight premenstrual rise and a 7.2% menstrual depression.( 4 ) The BMR of adolescent girls aged 12-17 in Guangzhou appeared a gradually decrease tendency with the growing process. The mean BMR values for aged from 12 to 17 were 164.64, 157.49, 152.13, 147.95,143.64,137.53 kJ.m-2.h-1 respectively The differences of BMR between aged 12 and 13 groups and the other age groups are statistical significant. This results are a littel (4.7-9.5%) lower than the figures of Fleish as compared with western count- rtes.( 5 ) There are seasonal changes of BMR for adolescent girls in Guangzhou. The BMR is 3.5% higher in Winter than in Summer-Autumn. (6) The BMR of adolescent girls are influenced by combined factors of surface area, body fat and pulse. The results are discussed.