Obesity Study: Examining Methodology and Design


The present paper aims at discussing three different methodologies used to manage the health issue of obesity. Thus, three scholarly articles, each one focused on the management of childhood obesity with the help of physical activities, have been located. The sources differ in methodology: one of the articles is qualitative, another is quantitative, and the third one employs a mixed-method design. The internal and external validity issues of each research are investigated. Also, the analysis of how a different design or methodology could have been beneficial for each study is offered. At the end of the paper, a summary of findings is provided.

Methodologies and Designs Used in Each Study

A Quantitative Study

The article employing the quantitative study design is focused on the relationship between obesity and such factors as dietary intake and leisure time activities (Winkvist et al., 2016). To perform their research, authors conducted a cross-sectional health survey among adolescents. Out of 21,651 eligible persons, 54.3% agreed to participate. Overall, 11,573 responses were available for the analysis: 50,7% of the surveys were filled in by girls, and 49.3% by boys (Winkvist et al., 2016). The major goal of the study design was the identification of eczema and asthma prevalence as related to environmental exposures. Besides, adolescents’ physical activity and dietary intake were analyzed. The questionnaire prepared by scholars included 73 semi-quantitative food frequency and lifestyle questions. Out of the 11,753 obtained surveys, 11,222 incorporated complete data on anthropometry and dietary intake, which constituted the basis for Winkvist et al.’s (2016) research. Statistical analysis used to evaluate the variables were the Chi-square test, independent sample t-test, and bivariate regression analyses.

External and internal validity issues

The internal validity of the study was high since cofounding variables were excluded. The changes in independent variables (leisure time and dietary intakes) were proved to be responsible for the variation observed in the dependent variable (obesity). In particular, it was confirmed that dietary habits of adolescents could have a positive impact on obesity (Winkvist et al., 2016). What concerns external validity, a possible threat to it might have been the lack of pre-survey research.

How a different methodology might have benefited the study

If a mixed-method approach had been used in research, it could have explained the causes of adolescents’ obesity from their point of view. Also, if participants had been asked about their opinions regarding the most positive interventions, it would have been easier to arrange some health prevention campaign for them. However, the study reached the goals set by the authors.

A Qualitative Study

The qualitative method was taken as a basis for research design by Bentley, Swift, Cook, and Redshell (2017) who investigated parental opinions on determining the future risk of childhood obesity in infancy. Scholars employed a qualitative survey to ask participants about their predisposition to being educated about obesity factors. Twenty-three parents took part in the semi-structured qualitative interviews (Bentley et al., 2017). The identified information allowed a distinction between three major topics. The first theme concerned the identification of infant obesity risk. The second topic involved the main outcomes of infant obesity. The third issue dealt with parental attributions if responsibility, causality, and control (Bentley et al., 2017). Interviews were conducted face-to-face, which increased the reliability of results. Upon completing the surveys, their transcripts were entered into QSR NVIVO Version 10 (Bentley et al., 2017). The sample was selected from parents from the same locality whose children were 12 months or younger.

External and internal validity issues

It is possible to conclude that there were some threats to the external validity due to the sample size. Although the authors considered their sample size adequate, it seemed that the results could have been different if more parents had been engaged in the study. What concerns the internal validity, it appeared to be high because of the substantial conclusion that provided strong evidence of causality.

How a different methodology might have benefited the study

The selected approach seems to be the most suitable one for such a study. There is no better way to investigate people’s opinions than asking them personally. If some aspects of the quantitative research design had been employed, it would have required a larger number of participants and more time for the analysis. However, scholars might have incorporated such a method of quantitative research as experiment to investigate the differences in opinions and outcomes in two or more groups of participants.

A Mixed-Method Study

The mixed-method design was employed in research by Pradeilles, Rousham, Norris, Kesten, and Griffiths (2016). In their study, scholars combined qualitative (community readiness model (CRM) surveys) and quantitative (focus group discussions (FGD)) approaches. According to the authors, the choice of the study design was justified by increased benefits of the mixed-method approach. In particular, it was mentioned that such a design enabled qualitative responses obtained from the participants to promote the interpretation of the meaning of quantitative readiness scores (Pradeilles et al., 2016). CRM surveys and FGDs were conducted with fifty-one religious leaders from Soweto and Johannesburg. The rationale for selecting the CRM survey was that it helped to establish the level of readiness of the community to participate in the obesity prevention program. With the help of the CRM, it became possible to evaluate six various dimensions of the issue: community efforts, leadership, knowledge of the problem, knowledge of efforts, resources, and community climate (Pradeilles et al., 2016).

External and internal validity issues

Internal validity of the study may be considered as high. Modifications in the independent variable (religious leaders functioning as role models) were responsible for the variation in the dependent variable (community’s attitude towards health behavior). However, the external validity is not high due to the inclusion of only one group of possible role models. Also, the sample size was not big enough to generalize findings.

How a different methodology might have benefited the study

It does not seem that a different method could have been more suitable for the analyzed source. The authors employed two different approaches, which made their analysis profound and multi-faceted. The exploitation of only qualitative or only qualitative design could not have provided such extensive data. Therefore, the mixed-method approach used by Pradeilles et al. (2016) may be regarded as the most beneficial of all.


The paper allowed analyzing and comparing research methodologies used in three different studies. Each of the articles was connected with the selected health issue. All studies were to some extent focused on childhood obesity and ways of managing it. Each of the sources described how the problem of obesity was managed in different localities and for different age groups. It has been established that the internal validity of all source is high whereas there were threats to external validity in almost all cases. The most beneficial research method was the combination of qualitative and quantitative features since it allowed for combining different analytical approaches when investigating results. However, each article offered valuable insights into the better understanding of the selected health issue.


Bentley, F., Swift, J. A., Cook, R., & Redshell, S. A. (2017). “I would rather be told than not know” ─ A qualitative study exploring parental views on identifying the future risk of childhood overweight and obesity during infancy. BMC Public Health, 17(1). Web.

Pradeilles, R., Rousham, E. K., Norris, S. A., Kesten, J. M., & Griffiths, P. L. (2016). Community readiness for adolescents’ overweight and obesity prevention is low in urban South Africa: A case study. BMC Public Health, 16(1). Web.

Winkvist, A., Hultén, B., Kim, J.-L., Johansson, I., Torén, K., Brisman, J., & Forslund, H. B. (2016). Dietary intake, leisure time activities and obesity among adolescents in Western Sweden: A cross-sectional study. Nutrition Journal, 15(1). Web.