The IHHP was the first community-based trial to assess the impact of a comprehensive, multi-component healthy lifestyle intervention program in a developing country. The findings revealed that the IHHP resulted in some complicated changes in mean values, as well as in the prevalence of cardiometabolic risk factors. Interestingly, the potential effects of school-based health intervention programs on lifestyle behaviors and CNCDs risk factors and surrogate markers are conflicting.
A study in India assessed the effectiveness of a multi-component intervention model of nutrition and lifestyle education on behavior modification, anthropometry and metabolic risk profile of urban Asian-Indian adolescents. At 6 months follow-up, significant improvements in several domains of knowledge and healthy lifestyle behaviors, as well as decreases in abdominal adiposity and blood glucose levels were observed in the intervention students in comparison with controls.19
However, since this study was not conducted at a large scale, its results might not be generalizable.
A controlled study in the US evaluated health-related knowledge of CVD risk factors before and after a 16-week school-based intervention among children in rural areas. It found health-related knowledge of rural adolescents possible to be increased through partnership with schools and multidisciplinary teams of health care professionals.20
In the present study, the interventional program on overweight and obesity seemed to be effective only in girls. In fact, despite the increments in boys of the IA and all students in the RA, overweight and obesity were slightly reduced in girls of the IA. Although some school-based interventions have had effects on overweight,21
most interventions, mainly those involving large cohorts, did not show promising effects.24
Moreover, numerous school-based programs have been successful in improving glucose levels, insulin sensitivity and inflammatory markers.27
The beneficial effects of IHHP comprehensive community-based lifestyle interventions were shown in changing some lifestyle behaviors among adult population16
as the program has also been positively effective on cardiometabolic risk factors among adult population.31
According to the present study however, it was less effective on adolescents. Our study combined a population-based approach with a school-based intervention aiming at children, teachers and parents.
As recommended by Berenson et al., the central thrust of health providers should be to help young generations grow up with healthful habits from the beginning, liberated from the harm of adverse lifestyles that were unwitting consequences of globalization and economic development.33
It is important to recognize that CNCD prevention from childhood requires a partnership. Although early researches in school health education, which focused on knowledge-based classroom programs, were able to make positive changes in students' knowledge and attitudes, they failed to improve health behaviors and related physiologic risk factors. Therefore, multiple factors should be considered in this regard. Governments, national and international organizations, consumers, industries and the media all play important roles in promoting healthy lifestyle from early life.
Lifestyle habits are influenced by the interaction between individuals and their social, cultural, and physical environments, not simply by knowledge about the healthfulness or harmfulness of different behaviors. Appropriate practice of evidence-based health promotion requires to consider the quality of available evidence, local values and prevailing resources. Each community must consider not only the development of scientific guideline strategies for its population but also strategies for effective and culturally-appropriate interventions to achieve the goals.
In conclusion, the IHHP interventions could to some extent have beneficial effects on cardiometabolic risk factors of adolescents. However, the efficacy of the program among adolescents was less than the adult population. It might reveal the youth to be more exposed to lifestyle changes. Therefore, more considerations and time should be paid to achieve favorable results. Providing the appropriate interventions to achieve health goals can only be one component of a comprehensive policy which must be embraced through intersectoral collaboration, and appropriately applied to be effective.