Weight perception and control behaviors among secondary school students in Trinidad and Tobago

Transcription

1 Weight perception and control behaviors among secondary school students in Trinidad and Tobago N. Brathwaite & L. Wilson, University of the Southern Caribbean, Trinidad & Tobago; Alabama State University, Montgomery, Alabama; Objective: To examine gender differences in perceived weight status and weight control strategies; and the relationship between such perceived status and the weight control strategies of adolescents in Trinidad and Tobago. Design and Methods: A nationally represented sample of 4448 fifth and sixth form students obtained through two-stage cluster sampling. Weight status and control behaviors were obtained by self-administered questionnaire. Cross-classification analyses provide gender difference data; binary logistic regression assessed the relationship between weight status and weight control behaviors. Results: Over half of the adolescents (53.7%) described their body weight as About Right. Males were more likely to say their weight was about right than females (56.3% vs. 51.0%). Males were a little more likely to say they were a little or very underweight (24.2% vs. 22.5%). Girls were more likely than boys to say they were a little or very overweight (26.5% vs. 19.6%). The data suggest that females were more likely than males to say they were trying to lose weight (35.0% vs. 25.1%). Males were more likely than females to use exercise (50.1% vs. 44.0%). Females were more likely to say they controlled weight by eating less (36.7% vs. 27.7%) or by fasting (11.2% vs. 8.9%). Compared to females who perceived their weights to be just right, underweight females are 3 times more likely to exercise or eat less; underweight males were 2.2 more likely to exercise, 3.3 times more likely to eat less. Using the same comparison group, overweight females were 3.3 times less likely to exercise, 3.8 times more likely to eat less; males are 5.5 times less likely to exercise, and only 2.3 times more likely to eat less. Conclusions: While weight status is a predictor of weight control behaviors, those with the greater risks are less likely to use exercise as a significant part of their weight control strategy. School health programmes should be sensitive to both social-psychological influences and gender influences on weight control behaviors. 1

2 INTRODUCTION Obesity is a well-known risk factor for many health problems; it is also a complex condition with serious social and psychological consequences that affect virtually all age and socioeconomic groups and threatens to overwhelm both developed and developing countries. This problem is increasing in adolescents and various factors contribute to it. The Caribbean Food and Nutrition Institute (CFNI) surveillance data on children and adolescents in the Caribbean indicate that those overweight and obese account for up to 15% of this group in various countries (CFNI, 2004). Given the significant prevalence rates it is instructive to understand more than the physiological and contextual factors related to overweight and obesity. Equally important are the social psychological dimension of the problem. Accordingly this paper investigates the relationship of the perception of weight status to weight control behaviors among adolescents in Trinidad and Tobago. Childhood obesity is a leading public health concern because overweight-obese youth suffer from co-morbidities such as Type 2 diabetes, nonalcoholic fatty liver disease, metabolic syndrome, and cardiovascular disease, conditions once considered limited to adults (Yoon Myung & SoJung, 2009). Overweight children are at higher risk for remaining overweight as adults, (Jeffery, Drewnowski, & Epstein et al., 2000), as well as for adult morbidity and mortality from cardiovascular disease (Must & Strauss, 1999). Physically active children are less likely to become obese than physically inactive children (Moore, Nguyen, Rothman, et al., 1995). In particular, engaging in high-intensity physical activity is associated with less abdominal fat, a further health risk factor (Yoon Myung & SoJung, 2009). The protective effect of physical activity against obesity is substantial and well known (Hill, 2000, DHSS, 1996). Essentially then, we suggest that the awareness of one s weight status should motivate certain types of control behaviors such as exercise and its complement, eating healthy. The primary question is whether the subjective knowledge (perception) of one s weight status increases or decreases the probability Design and Method Trend Research Empowering National Development (TREND) is a school-based student survey. TREND 2009 employed a two-stage cluster sample design to produce a representative sample of students in Forms 5-6. The first-stage sampling frame consisted of all schools 2

3 containing any of Forms 5-6. Schools were selected systematically with probability proportional to school enrolment size. Forty two (42) schools were selected to participate in the survey. The second stage of sampling consisted of randomly selecting intact classrooms from each school to participate. All students in the sampled classrooms were eligible to participate in the survey. A total of 4,448 or 16.5 % of the estimated 2008 (best available) 5 th & 6 th Form Population in Trinidad and Tobago completed the questionnaires. The sample demographics are representative of the general targeted population Results Weight and Weight Control Behaviors This study asked adolescents about their perceptions of being over or under weight. It also asked whether they were trying to control their weight, and what, if anything, they were doing, such as diet or exercise. Just over half of the adolescents in this study (53.7%) described their body weight as About Right (Figure 1). Males were more likely to say their weight was about right than females (56.3% vs. 51.0%). Males were a little more likely to say they were a little or very underweight (24.2% vs. 22.5%). Girls were more likely than boys to say they were a little or very overweight (26.5% vs. 19.6%). This is slightly lower than in the 2007 YRBSS in which 29.3% of adolescents described themselves as overweight (Eaton et al., 2008). Figure 1: Perception about weight 51.0% 56.3% 19.5% 3.0% 21.1% 3.1% 53.7% % 23.3% 3.2% 17.0% FE 2.6% 20.2% 2.9% VERY UNDERWEIGHT A LITTLE UNDERWEIGHT ABOUT RIGHT WEIGHT A LITTLE OVERWEIGHT VERY OVERWEIGHT FE Data on weight control activities (Figure 2) suggest that females were more likely than males to say they were trying to lose weight (35.0% vs. 25.1%), and males were more likely than females to say they were trying to gain weight (30.3% vs. 24.3%). Note also, the percentages 3

4 who were trying to stay the same weight or who were not trying to do anything about their weight (44.6% males, 40.6% females) were somewhat less than those who also said their weight was about right. Correlational analyses indicated a significant relationship (r=.33) between these activities and weight perception with the relationship for females (r=.37) somewhat stronger than males (r=.25) Figure 2: Weight Control Activities by Gender 35.0% 24.3% 24.0% FE 25.1% 30.3% 26.1% 16.6% 18.5% 30.1% 27.3% 25.1% 17.5% LOSE WEIGHT GAIN WEIGHT STAY THE SAME NOTHING Students were asked to respond to a variety of weight control behaviors: exercising, eating low-calorie or low-fat foods, fasting, taking diet pills, and vomiting or taking laxatives. Their responses are summarized in Figure 3. Figure 3: Weight Control Measures by Gender (last 30 Days) 44.0% 36.7% 47.1% 50.1% 32.2% 27.7% 11.2% 2.9% 2.9% FE 8.9% 4.3% 3.2% 10.1% 3.6% 3.1% EXERCISE EAT LESS FAST FOR 24 HOURS TAKE DIET PILLS VOMIT OR TAKE LAXATIVES FE 4

5 The most common response, overall and for both males and females, was exercise (47.1%). Males were more likely than females to use exercise (50.1% vs. 44.0%). Females were more likely to say they controlled weight by eating less (36.7% vs. 27.7%) or by fasting (11.2% vs. 8.9%). The least common responses were taking diet pills, powders, or liquids (3.6%) and vomiting or taking laxatives (3.1%). Logistic Regression Models We reduced the weight control measures into three dichotomous outcome measures: exercise/all others; eat less/all others and other behaviors (fasting, diet pills, vomiting and laxatives)/all others. Weight status was also reduced to three categories (underweight, overweight; just right). Finally, we constructed weight status x gender profile variable and estimated the odds ratios (Table 1) comparing all groups to Just Right females Weight Status x Gender Groups About Right Female (Reference Group) Table 1 Odds Ratio of Weight Status and Gender Influence on Weight Control Behaviors Weight Control Measures Exercise Eat Less Other Measures* Odds 95% CI Odds 95% CI Odds 95% CI Underweight Males Underweight Females Overweight Males Overweight Females About Right Males *Includes fasting, diet pills, vomiting, and laxatives. CONCLUSIONS Compared to females who perceived their weights to be just right, underweight females are 3 times more likely to exercise or eat less; underweight males were 2.2 more likely to exercise, 3.3 times more likely to eat less. Using the same comparison group, overweight females 3.3 times less likely to exercise, 3.8 times more likely to eat less; males are 5.5 times less likely to exercise, and only 2.3 times to eat less. The results were less differentiated for those using other measure and are the only non-significant odds ratios in the table (p.05). The data supports that those with the greater risks are less likely to use exercise as a significant part of their weight control strategy. 5

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