| Popis: |
The validity of estimates of energy intake in a group of young women, and the influence of body mass index (BMI) and concern over bodyweight on such estimates, were determined with the aid of a food record intake. The study subjects were a group of female university students between 20 and 32 years of age. Participants maintained a steady weight over the month-long experimental period. Their energy intake was, therefore, very similar to their theoretical energy expenditure. Discrepancies between intake and expenditure data can be used as an indicator of the degree of over or underestimation of intake. 29.7% of subjects had a BMI20 kg/m2, 5.5% showed BMIs of25 kg/m2, and none exceeded the lower limit of obesity (BMI30 kg/m2). Of those with BMI20 kg/m2, no significant differences were seen between intake and expenditure (-2.3%). However, those with BMIor = 20 kg/m2 showed discrepancies of 10.4%. In those with BMI25 kg/m2, this figure rose to 22.2% Concern over bodyweight, and the amount of weight that subjects wished to lose, increased with BMI (r = 0.72). However, even some subjects with BMI20 kg/m2 showed a desire to lose some weight (2.1 +/- 1 kg). A tendency was seen for subjects with BMIor = 20 kg/m2 to underestimate their food intake. This became more obvious with increasing BMI (r = 0.36). This could mean that obese women habitually underestimate food intake; a factor that could invalidate many dietetic studies published to date. In the present group, when BMI did not exceed 24 kg/m2, mean underestimation was 4.8%. However, subjects with BMIsor = 24 kg/m2 underestimated their intakes by 20.4%. Concern over bodyweight (assessed as kg a subject wished to lose) did not change the observed increase in underestimation with rising BMI. Anxiety, therefore, probably parallels true weight and BMI. |
