Abstract
Aims: To determine the effects of a nutrition and exercise weight management program supported by social cognitive theory on self-efficacy, body mass index and psychosocial functioning in adolescents aged 10-13 years (n=119).
Methods: A quasi-experimental intervention to improve self-efficacy for eating and exercise weight management for 59 overweight adolescents aged 10-12 years who participated in a 6-month weight-control self-efficacy programme. The control group consisted of 60 overweight adolescents. The changes in BMI, lifestyles and psychosocial functioning through self-efficacy beliefs, were assessed using the chi-squared and t-test.
Results: Weight loss at 6 months was 0.05 kilograms of baseline body weight, and self-efficacy scores increased in the range of 0.58 to 0.75 among adolescents in the intervention group, while for those in the control group, self-efficacy scores decreased by -0.15 to -1.03. Self-esteem was one of the psychosocial factors that caused the overweight and obese adolescents to eat appropriately and intend to exercise regularly. Thus, this intervention had the most significant impact on adolescents’ self-esteem (t=3.2, p=0.002) using the paired t-test between the pre- and post-tests.
Conclusions: Findings were consistent with the social cognitive theory, namely that improvement in self-efficacy over time supports greater weight loss. Adherence to exercise and appropriate eating can benefit weight-loss outcomes because individuals’ cognitive capability and belief in the intervention are taken into consideration by engaging them in pre-set actions and health outcomes.
*Corresponding author: Regina Lee, School of Nursing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, E-mail: Regina.Lee@polyu.edu.hk
Received October 18, 2012; Accepted November 22, 2012; Published November 24, 2012
Citation: Regina Lee LT, Loke AY (2013) A Quasi-Experimental Intervention to Improve Self-Efficacy for Eating and Exercise Weight Management: Short-Term Effects. J Nutr Disorders Ther 3:121. doi:10.4172/2161-0509.1000121
Copyright: © 2013 Regina Lee LT, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Keywords: Obesity; Self-efficacy; Chinese adolescents; Intervention;
Psychosocial functioning
Background
Overweight and obesity are the nation’s fastest rising public health concern and have become a top priority in both Hong Kong and Taiwan, which had prevalence rates of 21.7% and 16% respectively in 2010 [1]. Adequate exercise and healthy eating have an important role to play in the prevention of child and adolescent obesity. School-based interventions struggle to achieve meaningful and lasting effects on the adoption of healthy lifestyle behaviors [2]. It has been reported that the effects of the conventional approach, with the single goal of adolescent weight loss, are the subject of debate [3]. Theorists have suggested that this may be due to the failure to incorporate psychosocial mediators as they relate to behavior change [4,5].
There is strong evidence suggesting that alternative interventions focusing on social cognitive variables and incorporating psychosocial mediators such as self-efficacy for behavioral maintenance are effective [6-8]. However, very few studies have focused on the impact of self-efficacy on the effectiveness of lifestyle modification for overweight adolescents [9-11]. Thus, it is critical to examine the role of self-efficacy as the psychosocial mediator, with the intention of assisting individuals in preventing weight gain, optimizing individual weight loss interventions, and achieving long-term weight loss maintenance.
Despite an increasing number of publications on childhood obesity in Western countries over the past decade [12-14], similar information regarding the Hong Kong population is scarce. Nevertheless, no study has measured Hong Kong adolescents’ self-efficacy and intention to practice healthy lifestyle behaviors, or assessed its potential influences in initiating behavior change. Public health policies and protocols have increasingly recognized the importance of a higher level of scope in enabling actions as an essential component to programs and settings-based initiatives in addressing these public health problems [15].
Social cognitive theory explains how an individual acquires and
maintains certain behavioral patterns, and it also provides the basis for intervention strategies [16]. This study followed a cohort of 10- to 13-year-olds who was identified as overweight or obese. Its aim was to examine the impact of social cognitive theory in the association between self-regulatory weight management interventions and self-efficacy beliefs in their ability to increase their motivation and intention to exercise and eat appropriately for 6 months.
Methods
The self-efficacy weight management intervention in this study was planned and delivered to 59 overweight and obese adolescents aged 10-13 (one dropped out after starting the interventions) for 6 months in two selected primary schools in Hong Kong. The intervention group benefited from self-regulatory interventions including daily self-weighing make a declaration of how much weight they wanted to lose, a weekly dietary log sheet, monthly dietary consultation sessions, daily planned physical activity lessons, regular group gathering and sharing sessions with a reward system, and monthly behavioral counseling sessions based on the self-reported weekly dietary log book.
The study was conducted in four primary schools in Tsing Yi Island in Hong Kong. Tsing Yi Island, located in the northwest of Hong Kong, is inhabited by a low socio-economic class including a dense population
Volume 3 • Issue 1 • 1000121J Nutr Disorders Ther
ISSN: 2161-0509 JNDT, an open access journal
Citation: Regina Lee LT, Loke AY (2013) A Quasi-Experimental Intervention to Improve Self-Efficacy for Eating and Exercise Weight Management:
Short-Term Effects. J Nutr Disorders Ther 3:121. doi:10.4172/2161-0509.1000121
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of new immigrants from mainland China. The four schools had 200-700 primary school students aged 6-13 from primary one to primary six (P.1-6) during the period of data collection. The study was conducted over a period of eight months in 2009. This period was chosen to identify the usual pattern of primary school students’ health practices by avoiding seasonal holidays and stressful periods such as examination time. Primary four to primary six (P.4-6) school students whose body weight was over the 85th percentile and whose parents allowed them to participate in the self-efficacy beliefs weight management program were recruited from the four selected primary schools to join the study. Prior consents were obtained from the parents of the primary school students via the school before the commencement of the study. The health education and P.E. teachers helped with the distribution and collection of the questionnaires in each school.
Intervention
The self-regulatory weight loss intervention was a community collaborative project using an interdisciplinary approach including university academic staff, school teachers (health education and physical exercise teachers), and a nutritionist. The intervention helped children in the two selected schools to adopt and sustain healthier lifestyles by enhancing awareness, changing behaviours or creating an environment that supports good health practices earlier in their early adolescence in the school settings. Helping adolescents to establish healthy lifestyles and avoid developing health risk behaviours is crucial and should be started before these behaviours are firmly established. The project team has developed a self-regulatory weight management program in collaboration with university academic staff, paediatric consultant, school nurses, school principals, school teachers and parents to support the physical, mental, emotional, behavioural and social well-being of overweight and obese adolescents. The project also enjoyed the partnership of non-governmental organizations with the similar aim of developing healthy adolescents who are capable of being successful learners.
For overweight and obese adolescents in the intervention group, a nutritionist with experience and education in dietetics and nutrition worked with the school food services to guide the progress toward achieving their goals over time. The nutritionist also provided consultation for the design of health education talks related to healthy eating (smart food choices, fewer added sugar beverages, more water intake, a healthy kitchen, awareness of the broader benefits of a variety of food choices, and the synergy between physical activity and food choices). The nutritionist continued to provide guidance to food providers, delivered nutritional talks to parents and expanded the food and nutrition messages by designing a series of group activities (one per month for a total of 10 sessions) to increase their knowledge, enhance their decision-making skills, promote peer involvement and interaction in the sharing session and support group, and enhance social influence.
People tend to avoid activities that they believe exceed their coping