The effect of a comprehensive intervention on anthropometric indices, dietary intake, and physical activity of adolescent boys with overweight

Abstract

Background

Non-communicable diseases in adulthood are reported to be strongly associated with adolescent obesity. The present study aimed to assess the effect of a comprehensive lifestyle modification intervention on the anthropometric indices, dietary intake, and physical activity of adolescent boys with overweight.

Methods

This pragmatic trial was conducted on 126 adolescent boys with overweight. A comprehensive school-based intervention was carried out at two levels for four months: at the school level based on the Ottawa Charter framework and at the personal level including individualized diet and physical activity.

Results

The percentage of mean difference of BMI and BF loss in the intervention group were 1.20% (P < 0.05) and 6.41% (P < 0.01), respectively. The intervention group had a lower intake of calorie (2350 ± 861 vs. 2634 ± 917 kcal/d), carbohydrate (255.68 ± 41 vs. 286.97 + 47 g/d), and fat (112.67 ± 78 vs. 217.72 ± 86 g/d) after the intervention compared to the control group (All P < 0.05). The intervention resulted in a significant increase in physical activity parameters including distance (3501 ± 287 vs. 614 ± 56 m/d), duration (203 ± 35 vs. 72 ± 10 min/d), and calorie expenditure (359.24 ± 62.4 vs. 46.74 ± 7.5 kcal/d) in the intervention group compared to the control group (P < 0.01).

Conclusion

A comprehensive lifestyle modification intervention which covers both school and individual levels may positively influence BMI, body fat, calorie intake, and distance and duration of physical activity in adolescents. Thus, adopting multifaceted strategies using the Ottawa Charter framework may be considered as an effective approach to managing obesity in adolescents.

Introduction

Obesity among adolescents is a prevalent public health concern globally [1]. The increasing prevalence of adolescent obesity [2] can lead to an increase in the prevalence of adult obesity in the world [3]. Obesity in adolescence is a contributing risk factor for various non-communicable diseases such as cardiovascular diseases, type 2 diabetes, and certain types of cancer [4–6]. The World Obesity Federation estimates that there will be 254 million children and adolescents with obesity by 2030 ¹. Interactions between biological, social, environmental, and behavioural factors may cause obesity in children and adolescents [7].

Interventions for adolescents with obesity focus on lifestyle modification, such as dietary changes, increased physical activity, and behavioural therapy [8]. For example, consumption of fruits and vegetables and limited soft drinks decreased obesity rates in adolescents [9, 10]. In addition, Physical activity is crucial in preventing overweight and obesity in young individuals [11]. Behavioural therapies such as cognitive behavioural therapy (CBT) help children to regulate their eating and activity for weight management. Combining exercise with dietary approaches has been shown to be an effective strategy for obese adolescents to improve maximal grip strength, reduce body mass index (BMI), and influence multiple facets of self-control [12].

A previous study evaluated the effect of a multidisciplinary intervention that combined nutrition, exercise, and psychological support in a family-based approach for boys with overweight, focusing on cardiometabolic risk and other health measures and found significant improvements in body composition, adherence to a Mediterranean diet, and physical performance after the intervention [13]. Also, another study evaluated a personalized lifestyle modification interventions for adolescent girls with overweight, comparing it with usual care showed a significant reduction in BMI z scores for those in the intervention group compared to controls, with no significant differences in metabolic or psychosocial outcomes [14].

Although, adolescent obesity is reported to be influenced by different factors and modifications should be recommended within the context of the family, schools, and health services [15]. Few studies applied a specific framework to implement obesity interventions in adolescents. The Ottawa Charter for Health Promotion is a global agreement for the implementation of health interventions that includes five key action including build healthy public policy, create supportive environments for health, strengthen community action for health, develop personal skills, and re-orient health services [16]. In this charter, not only the role of lifestyle modification in health promotion has been discussed, but environmental and social factors have also been taken into consideration [17]. There is evidence on a correlation between adoption of the Ottawa Charter’s framework of five action areas and health promotion program effectiveness [17], and also there are several reports on benefits of implementing health-promoting schools to prevent obesity [18]. Due to the lack of sufficient evidence regarding the impacts of comprehensive interventions based on standard frameworks on different aspect of body composition and lifestyle of adolescents, this study aimed to investigate the effects of a comprehensive lifestyle modification intervention based on the Ottawa Charter framework on anthropometric indices, dietary intake, and physical activity of adolescent boys.

Methods

This pragmatic trial was conducted on 12- to 16-year-old adolescent boys enrolled in two junior high schools in District 5 of Tehran, Iran. The schools were randomly assigned as the intervention and control schools. The sample size was determined using Open EPI online software based on α = 0.05 and β = 80 and the odds ratio of a similar previous study [19]. Overall, 126 students, including 63 boys with overweight for each of the intervention and control groups were recruited.

The inclusion criteria for the study were the written consent of the student and his parents, BMI ≥ z-score + 1 for age and sex, absence of conditions affecting weight, not using medication affecting weight, and not following a weight-loss diet program. The exclusion criteria were failure to comply with the intervention and/or withdrawal of participation. The interventions were carried out according to the schedule for four months in the intervention school. The control group school was subjected to observation and regular activities.

Physical activity

The physical activity of the students was evaluated using a validated physical activity tracker (Mi Band 1 Plus, Xiaomi Co.) for an average of one week (with a minimum of 3 days) [20]. The device is a bracelet that evaluates physical activity along three axes (horizontal, vertical, and diagonal), counts the number of steps, measures travel distance, and calculates the duration of activities (minutes/day) and energy expenditure (Kcal/day). The students were instructed to wear the bracelet throughout the day, except for periods of contact with water (e.g., showering, swimming). Individual accounts were created for each student in the Mi Fit application, and the data from the bracelets was stored in mobile phone through synchronization.

Anthropometric measurements

Heights were measured in the standing position and without shoes using a standard measuring tape attached to the wall. Body weight was assessed to the nearest 0.1 kg without shoes and wearing light clothing. Data on anthropometric indices, including body mass index (BMI), body fat percentage (BF), body muscle mass percentage (BM), and basal metabolism were collected using a validated bio-impedance analyzer (BIA) (Omron BF-511, Kyoto, Japan) [21], and the students were assessed according to the standard cut-offs for BMI [22] and body composition [23].

The intervention

The intervention was designed according to the Ottawa Charter for health promotion and was staged at two levels in the intervention school for 16 weeks:

• A school-based intervention for all students at the intervention school.

• An intensive intervention for boys with overweight in the intervention group.

School-based intervention

A school-level health promotion intervention based on the Ottawa Charter health promotion framework aimed at changing weight-related behavior was performed for all students at the intervention school. The interventions were staged according to the five dimensions of the Ottawa Charter including (1) building healthy public policy, (2) creating supportive environments, (3) strengthening community action, (4) developing personal skills, and (5) reorienting health services [24]. The objectives of the intervention base on these 5 dimensions were as follow: (1) adjusting the school’s policy regarding nutrition and physical activity at school, (2) a supportive environment for the creation and reinforcement of a supportive environment for providing healthy low-calorie foods and performing physical activity at school and home, (3) community action and involving all family members, school personnel and students to achieve healthy weight, (4) to promote the personal skills, knowledge, perspectives, and performance to adopt a healthy diet and healthy levels of physical activity, and (5) to make changes to the school’s health services regarding nutrition and physical activity.

To start the intervention and adjust the existing policies regarding students’ food intake at the intervention schools (the first dimension), the importance of healthy snacks was discussed with the operators of the school’s buffet and unhealthy foods such as chips and falafel sandwiches were removed from the school. Regarding providing a supportive environment (the second dimension), several posters on improving nutrition and physical activity were installed on the walls around the school. Also, free healthy snacks were provided to the intervention group on non-holiday days for 16 weeks according to the following schedule: Saturday: chicken sandwich (baguette, chicken, tomato sauce, and cucumber); Sunday: cheese sandwich (baguette, cheese, walnut, and cucumber); Monday: dried fruit (sour cherry, prune, and fig); Tuesday: nuts and dried fruit (soybean, dried date, raw pistachio, and raw almond); Wednesday: fresh fruit (strawberry and unripe green plum). Furthermore, written instructions were provided for all teachers to dedicate five minutes in every class to health-related messages. The instructions included a brochure covering 10 health-related messages and some explanations for each message.

To foster community action (the third dimension), interested students were involved in data collection by starting a health campaign after receiving instructions on how to help with the research and collect data. The student collaborators would also encourage the other students to follow the recommendations provided by the researchers and thus contribute to the success of the intervention. In an educational session, parents were encouraged to walk their children to and from school if possible. If not, the parents were asked to park their cars some distance from the school and ask the children to walk some of the way. Finally, a competition was designed, rewarding students who had lost the most weight during the intervention.

To develop the personal skills of students and parents (the fourth dimension), brochures and booklets containing information on physical activity and healthy nutrition were distributed among the students. The intervention group was reminded of the recommendations through weekly phone calls. Furthermore, 30 health-related text messages whose contents which were designed by the research team were sent to the students and their parents. After making arrangements with the intervention school, parents and school personnel were invited to a meeting focusing on a healthy lifestyle including healthy nutrition and the food pyramid, appropriate physical activity, suitable nutrients for children and students, calculating the ideal body weight (IBW), and the importance and applications of measurements of weight, BMI, BF, BM. To reorient health services regarding nutrition and physical activity (the fifth dimension), school personnel were instructed on the importance of weight management in adolescents and how to use the available tools at school (e.g., scale, stadiometer) for the monthly monitoring of students.

Intensive intervention

Initially, 126 students were included in the personalized intervention, but 30 were excluded due to failure to comply with the study, resulting in a final sample of 96 people including 43 students from the control school and 53 students from the intervention school.

An intensive intervention including a personalized diet and a physical activity program was carried out for 16 weeks in the intervention group. A personalized 16-week weight loss diet was designed for each student according to his 24-hour dietary recall, metabolism, and the level of physical activity. The diets were designed in such a way that the participants’ daily caloric intake gradually decreased compared to the amounts they normally received. Students received oral and written instructions on how to correctly follow their personalized diets.

At the same time, the intervention students participated in a high-intensity interval training (HIIT) program (three 90-minute sessions a week for 16 weeks). Recent studies reported that HIIT may contribute to weight loss and improve body composition [25].

Students participated in exercise sessions after school on Saturdays, Mondays, and Wednesdays by doing exercises for 90 min under the supervision of a sports physiologist and a qualified trainer. The session started with a 10-minute warm-up (stretches, aerobics). Next, the students were divided into groups of four and ran across the schoolyard at maximum speed followed by 4–5 min of rest. The sessions ended with stretches to cool down. The intensity of the exercises increased with each passing week in step along with the student’s increased capacity, according to a pre-determined protocol. The necessary instructions for exercising at home were also provided at the end of each training session. Educational sessions about healthy lifestyles, healthy nutrition, and physical activity were performed for the students three times a week (for 16 weeks). The students and their parents also received reminders through phone calls, and their questions were addressed.

Statistical analysis

Chi-squared and independent t-test methods were used to analyze qualitative and quantitative data, respectively. GLM repeated measures were utilized to analyze the effects of the intervention and to compare changes between the intervention and control groups. The normality of the dependent variables was assessed using the Shapiro-Wilk test. The assumption of sphericity was tested using Mauchly’s test of sphericity. Data were analyzed using SPSS (Version 23( and P < 0.05 was considered significant in all analyses.

Results

The mean age of the intervention and control groups was 14.02 ± 0.96 vs. 13.79 ± 0.86 years, respectively (P = 0.23). After 16 weeks of intervention, BMI (Mean difference: -0.32 or 1.2%, F = 6.58, P < 0.05) and BF (Mean difference: -1.81 or 6.5%, F = 10.5, P < 0.01) were significantly decreased in the intervention group compared to the control group. The mean BMI and BF of the intervention group significantly decreased from 26.73 ± 4.18 kg/m2 and 28.24 ± 6.55 kg to 26.41 ± 4.21 kg/m2 and 26.43 ± 7.21 kg, respectively. No significant differences were observed among other anthropometric indices (weight, height, and BMI) (Table 1).

Table 1.

The anthropometric indices of the participants at the beginning of the study and after four months of intervention (n = 96)¹

Anthropometric variables	Mean				Mean Difference		F value
	Before intervention		After intervention				Group	Time	Group × time
	Control	Intervention	Control	Intervention	Control	Intervention
Weight (kg)	74.44 ± 11.83	74.45 ± 14.46	77.06 ± 12.27	73.58 ± 14.21	2.62	-0.87	3.6	3.6	0.05
Height (cm)	168.76 ± 8.11	165.75 ± 8.58	169.03 ± 8.85	166.95 ± 9.29	0.27	1.2	0.26	0.26	1.44
BMI (kg/m2)	26.05 ± 2.96	26.73 ± 4.18	26.56 ± 2.89	26.41 ± 4.21	0.51	-0.32	0.27	0.27	6.58*
BF (%)	27.08 ± 6.19	28.24 ± 6.55	26.43 ± 5.87	26.43 ± 7.21	-0.65	-1.81	0.01	0.01	10.5**
BM (%)	35.32 ± 2.59	34.82 ± 2.67	35.47 ± 2.43	35.47 ± 3.37	0.42	0.65	0.38	0.38	2.14

¹ Based on repeated measures GLM (df = 1) after adjusting for the confounding effects of genotype, age, and anthropometric variables at P < 0.05 * and P < 0.01 **

Regarding the effect of the intervention on dietary intake, the intervention led to a significant decrease in carbohydrates (255.68 vs. 286.97 g/d, F = 4.06, P < 0.05), fat (112.67 vs. 217.72 g/d, F = 26.65.58, P < 0.01), and energy (2350 vs. 2634 kcal/d, F = 6.21, P < 0.01) intake in the intervention group compared to the controls (Table 2). The reduction in protein intake was not statistically significant, which was expected given the low-calorie, high-protein diet prescribed for the intervention group.

Table 2.

The effects of the intervention on dietary intake among the intervention and control groups [1]

	Mean				F value
	Before intervention		After intervention		Group	Time	Group × time
	Control	Intervention	Control	Intervention
Energy (kcal)	2550 ± 701	2925 ± 889	2634 ± 917	2350 ± 861	0.27	3.03	6.21**
Protein (gr)	97.17 ± 28	162.34 ± 59	106.81 ± 42	158.98 ± 46	9.34**	3.42	0.42
Carbohydrate (gr)	197.15 + 28	264.43 ± 33	286.97 ± 47	255.68 ± 41	73.62**	0.03	4.06*
Fat (gr)	203.35 ± 91	135.33 ± 50	217.72 ± 86	112.67 ± 78	10.83*	0.42	26.65**

¹ Based on repeated measures GLM (df = 1) after adjusting for the confounding effects of genotype, age, and anthropometric variables at P < 0.05 * and P < 0.01 **

Regarding physical activity, the results showed that compared to the control group, the health promotion intervention led to a significant increase in traveled distance (3501 ± 287 vs. 614 ± 56 m/d, F = 23.21, P < 0.01) and calorie expenditure (359.24 ± 62.4 vs. 46.74 ± 7.5 kcal/d, F = 455.79, P < 0.01) in the intervention group through physical activity. The improvement in traveled distance and calorie expenditure in the intervention group was achieved despite a reduction in the duration of physical activity from 203 m to 135 m per day (Table 3). This is most likely due to the intensive exercise program three times a week and the recommendations toward increasing exercise and physical activity for students in the intervention group, who would travel longer distances over a shorter period and experience higher energy expenditure.

Table 3.

Mean physical activity and calorie expenditure during physical activity for the participants at baseline and after the intervention

	Mean				F value
	Before intervention		After intervention		Group	Time	Group × time
	Controls	Intervention	Controls	Intervention
Distance (m/day)	631 ± 59	1293 ± 129	614 ± 56	3501 ± 287	32.88**	0.46	23.21**
Duration (min/day)	74 ± 11	135 ± 26	72 ± 10	203 ± 35	7.79**	0.43	0.42
Calorie expenditure (kcal/day)	50.16 ± 8.2	134.34 ± 34.6	46.74 ± 7.5	359.24 ± 62.4	45.48**	0.99	455.79**

¹ Based on repeated measures GLM (df = 1) after adjusting for the confounding effects of genotype, age, and anthropometric variables at (P < 0.05)* and (P < 0.01)**

Discussion

In the present study, a comprehensive intervention based on the Ottawa Charter in a short period of time resulted in the improvement of anthropometric indices, physical activities, and dietary intake, which was in line with some previous studies [19, 26–28]. The intake of carbohydrates, fat, and calories in the intervention group was significantly decreased. Also, a significant decrease was found in BMI and BF of the intervention group. Moreover, the physical activity indices, such as total distance covered and energy expenditure were significantly increased in the intervention group. Also, the body muscle mass increased, but did not change significantly, which is in agreement with other similar studies [19]. Research by Miguel-Etayo et al. [27], which contained 12-month lifestyle modification interventions in adolescents with obesity, reported an increase in fat-free mass and a decrease in BF. These results match the results obtained in this study, indicating that interventions in the lifestyle of adolescent boys with obesity can lower the BMI and BF ratio.

Dobrosielski et al. reported that 12 weeks of following a low-calorie diet and 90 min of physical training per week can cause a 9% weight loss and a 5% decrease in BF among participants [29]. These results were in line with the studies done by Parks et al. [26] with a 9-month follow-up and Lazzer et al. [28] with a 3-month follow-up that reported decreased BF percentage and intact muscle mass. However, changes in the body-weight was not significant in the present study. Body weight may not be a suitable indicator for assessing obesity in adolescents due to the increase in muscle mass and changes in body composition during this age range [19]. Thus, promoting physical activities and lifestyle changes, accompanied by eating habits, can be considered a strategic approach in the prevention of obesity among children and adolescents. Eating habits form in the early years of life and continue in adulthood, and their effects can influence the health status [30, 31].

In the present study, Ottawa Charter framework was used to design a multi-dimensional intervention involving adolescents, their family, the community, and the environment. A recent study indicated that there was a correlation between adoption of the Ottawa Charter’s framework of five action areas and health promotion programme effectiveness [17], and also several reports on benefit of implementing health-promoting schools in obesity prevention [18, 24]. Dao et al. [32] indicated that multi-dimensional interventions is associated with significant improvements in anthropometric indices of adolescents compared to single-dimensional interventions. For example, organized, multidimensional interventions were associated with improvements in eating habits and physical functions compared to Mediterranean diets [13]. Multidimensional approaches may be the most effective strategies for changing adolescents’ lifestyles and can affect both adolescents and their families [33, 34]. These approaches are accompanied by lifestyle improvements in eating habits and physical activities, which can be effective in controlling obesity in children.

Two major limitations of this study were the short follow-up and male-only participants. Due to the comprehensive and intense nature of the interventions, we shortened the duration of the intervention. Also, due to the gender segregation of schools in Iran and the higher prevalence of obesity in Iranian boys [35], this study was conducted only on adolescent boys. These limitations make it hard to generalize the obtained results to the rest of society. Also, both the intervention based on the Ottawa Charter and lifestyle modification were carried out simultaneously in the same school, and it was not possible to separate the effects of these two interventions from each other in order to investigate the impact of each of them separately. Furthermore, due to the possibility of the activity tracker wristbands being uncomfortable underwater, students’ aquatic activities such as swimming were not evaluated. More research, particularly in different genders and races are suggested to unfold the hidden sides of the interconnection between lifestyle modification and health outcomes in adolescents.

Conclusion

The results of this study indicated that the implementation of a comprehensive intervention program based on the Ottawa Charter framework on adolescent boys was associated with the improvement of anthropometric indices, dietary intake, and physical activity. These interventions reduced BMI, BF mass, reduced fat and carbohydrate intake, as well as increased physical activity indicators such as the distance travelled and the amount of energy expenditure compared to the control group. Promoting physical activity and lifestyle changes based on a school-based multi-dimensional intervention that include a wide range of strategies which involve adolescents and families may be considered as a multifaceted solution to deal with obesity. Further studies are recommended to prove the obtained results and discover the underlying mechanisms of the effect of lifestyle modification interventions on obesity related indicators in adolescents.

Author contributions

SD, FSHJ, ZM, SM, AA, KHAM, SHM, MT, and MGH designed the study and were involved in the data collection, analysis, and drafting of the manuscript. ZS, SKH, NK, PM, and SD were involved in the design of the study, analysis of the data, and critically reviewed the manuscript. All authors read and approved the final manuscript.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

This study was approved by the Ethical Review Board at Shahid-Beheshti University of Medical Sciences, Tehran, Iran (Code: IR.SBMU.nnftri.Rec.1402.089). A written consent form was obtained from all participants at baseline. Trial Registration Number is IRCT2016020925699N2, Registration date: 2016-04-24.

Consent for publication

Institutional consent forms were used in this study.

Competing interests

The authors declare no competing interests.

Funding

Funding for this study was provided by Shahid Beheshti University of Medical Sciences, Tehran, Iran (Code 43006550).