Overweight and obesity in students of a dental college of Karachi: lifestyle influence and measurement by an appropriate anthropometric index.
OBJECTIVE
To compare body mass index (BMI), waist circumference (WC), and body fat percentage (%BF), as index of overweight and obesity in young adults. We also intended to find an association between lifestyle behaviours and obesity.


METHODS
A cross-sectional study was conducted at Fatima Jinnah Dental College, Karachi, during 2007 to 2008, with 192 first year dental students, (18-21years) of high socioeconomic class. All were questioned regarding lifestyle behaviours. Overweight and obesity were estimated by measuring %BF, BMI, and WC. For %BF, skinfold thickness was measured using skinfold calipers. BMI > or = 23.0-24.9 kg/m2 was taken as overweight and > or = 25.0 kg/m2 as obese (Asians criteria proposed by Western Pacific Regional Office of World Health Organization). WC using Asian cutoff values for overweight and obesity were: males > or = 78 cm and > or = 90 cm; females > or = 72 cm and > or = 80 cm, respectively. Body fat percentage used to define overweight and obesity was: males 22.1-27.0 and > 27.1; females 27.1-32.0 and > 32.1, respectively. Pearson's correlation was done between the BMI, WC and %BF with statistical significance taken at P < 0.01.


RESULTS
BMI (Expressed as mean +/- SD) in males and females was 23.82 +/- 3.88 and 20.98 +/- 4.12 respectively. WC was 83.63 +/- 10.20 cm in males and 70.22 +/- 9.36 cm in females. %BF was 22.32 +/- 6.27 in males and 28.73 +/- 6.65 in females, with an overall 60.8% females and 44.4% males found to be overweight or obese. Obesity was underpredicted by BMI when compared to skinfold calipers method. The obese were seen to skip breakfast more often [odds ratio (OR): 2.39], take frequent snacks (OR: 1.58), watch television more (OR: 1.58), and were physically less active than their non-obese counterparts.


CONCLUSIONS
Body fat percentage using skinfold caliper is a reliable index of obesity. Lack of sleep and skipping of breakfast, are prominent promoters of obesity, in addition to other lifestyle behaviours.
Hingorjo
Mozaffer Rahim
MR
Department of Physiology, Fatima Jinnah Dental College, Karachi, Pakistan.
Syed
Sadiqa
S
Qureshi
Masood Anwar
MA
D000293:Adolescent; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D006305:Health Status Indicators; D006801:Humans; D008019:Life Style; D008297:Male; D009765:Obesity / Q000145:classification / Q000453:epidemiology*; D016017:Odds Ratio; D050177:Overweight / Q000145:classification / Q000453:epidemiology*; D010154:Pakistan / Q000453:epidemiology; D012307:Risk Factors; D012575:Schools, Dental / Q000706:statistics & numerical data*; D012885:Skinfold Thickness; D013223:Statistics as Topic; D013335:Students, Dental / Q000706:statistics & numerical data*; D055105:Waist Circumference; D055815:Young Adult