Dietary Practices and Physical Activity of Overweight and Normal Weight Malaysian Female Adolescents

Body image plays an important role in the management of body weight, especially among female adolescents. This study examined the differences in body image perception, weight management knowledge, eating behaviour and physical activity between overweight and normal weight Malaysian female adolescents. Body mass index screening was done on 588 secondary school students to identify overweight (OW) and normal weight (NW) subjects. A BMI-for-age of => 85th percentile and between => 5th and < 85th percentile were used as cut-offs for identifying suitable subjects of overweight and normal weight, respectively. Fifty girls identified as being OW were matched for age and ethnicity with 50 NW students. Subjects completed a self-administered questionnaire on demographics, eating behaviour and physical activity, a weight management knowledge inventory (WMKI) and the Body Silhouette Chart. The study sample comprised Malays (40%), Chinese (30%) and Indians (30%) with a mean age of 14.76 ± 1.15 years. The majority of them were from families with a monthly household income of less than RM1,000. Significantly more NW subjects (χ2=6.112, p=0.013) than OW subjects had incorrect perception of their current body weight status. The WMKI revealed that more OW subjects (64%) than NW subjects (52%) had a low level of weight management knowledge. Eating behaviour patterns were not significantly different between OW and NW subjects, but more OW subjects skipped one or more daily meals as compared to their NW counterparts (χ2=0.174, p=0.010). Physical activity patterns were similar in both groups. Healthy eating and physical activity promotion programmes in schools should include sound weight management practices. Correspondence author: Assoc Prof Dr. Mirnalini Kandiah, email: mirna@medic.upm. edu.my adolescence may persist into adulthood, increasing later risk for chronic conditions such as diabetes, heart disease, hypertension, stroke and some types of cancers. Malaysia is at the crossroads of nutrition and lifestyle transition. Economic and technological advancements in the past three decades have led to increased purchasing power and an unprecedented affluence with concomitant changes in lifestyles. Malaysians are increasingly consuming diets that are high in fat and calories and generally leading sedentary lives (Tee, 1999). While under-nutrition is still found in remote parts of Malaysia, more children and adolescents are overweight now than ever before (Ismail & Tan, 1998). In a large study of over 6000 school children aged between 7 and 16 years, overweight and obesity prevalence were found to be 6% and 3.6% respectively (Kasmini et al., 1997). This study and other data strongly indicate that the problem of overweight and obesity will pose a major public health challenge for Malaysia in the years to come. Adolescence is a transitional period that involves physiological, psychological and social changes that may contribute towards the development of overweight or obesity. A number of predisposing factors have been identified, which include among others, genetic disposition, diet, physical activity and environmental factors. Genetic and metabolic factors create the foundation in which cultural, environmental and social factors merge to determine body weight. Since the roots of adult obesity and its subsequent effects on morbidity are laid down in childhood, early identification of the risk factors is pertinent and bears important public health implications. Body image plays an important role in the management of body weight, especially among female adolescents. A high incidence of body dissatisfaction in adolescent girls has been repeatedly reported in the literature (Cooper & Goodyear, 1997; Pritchard, King & Czajka-Narins, 1997). Research has shown that with increasing age, the prevalence of body shape and weight concerns during adolescence rises from one in 10 among 11 year olds to one in five among 15-16-year olds (Cooper & Goodyear, 1997). However, little research has been reported on body image and weight concerns in Malaysian overweight children and adolescents. The assessment of body image in relation to overweight or obesity is important in order to understand its relationship to the maintenance of excess weight or in initiating motivation for weight reduction. It has been suggested that these concerns and dietary restraint may be more prominent among overweight adolescents. Childhood obesity has been implicated as a risk factor for the development of anorexia nervosa and bulimia nervosa (Fairburn et al., 1999) Eating behaviours and attitudes also influence weight gain in adolescents. Obese adolescents have been reported to consume larger meals with a higher percentage of energy from fat and protein than normal weight adolescents (Ortega et al., 1995). Restrained eating and skipping of meals have not often been investigated in overweight girls. It is likely that overweight adolescents may practise dietary restraint and erratic eating behaviour more consistently and this needs to be investigated. Overweight children and adolescents have been found to have a relatively low level of aerobic power and performance fitness. Studies have shown that individuals with a low level of physical activity have greater body weight and body fat levels as compared to their active counterparts (Schulz & Schoeller, 1994; Ryan, Nicklas & Elahi, 1996). Variations in physical activity and fitness by age and gender have also been observed. Sallis (1993) noted a decline in aerobic power of about 2% per year in female children and adolescents relative to body mass, while overall physical activity declined by about 7.4% 132 Pon LW, Kandiah M & Mohd Nasir MT