I found a piece of interesting news on the website of New York Times. [1]This news reveals the potential association between childhood obesity and school lunch. The research was conducted among the children who study in Southeastern Michigan schools. The result indicates that, the children who consumed school lunch on daily basis have 29% more risk of developing obese problem than the children who ate home-made lunch. The research also explore the link between watching TV or video games and obesity issue. The long time spending on watching TV and video games could also contribute to the increase in risk of obesity.
Afterward, I searched the original article related to this piece of news. [2] I think asking questions is a good way to learn the health articles, so, I will pose some questions below to understand this article.
What is the exposure and disease?
Answer: The exposure in this research is the school lunch consumption, and watching TV or video games. The disease is obesity.
What are the measured and unmeasured confounders?
Answer: The measured confounders: The age, gender, ethnics/racial factors, height, weight, blood pressure, serum cholesterol, glucose, total cholesterol, high-density lipoprotein, physiologic characteristics, dietary characteristics, physical activity, sedentary activities, lipid profile and heart rate.
The unmeasured confounders: Genetic information,the BMI and other obesity indicators of parents, stress level, emotional status, disease history, medicine and treatment in the recent period and family income. In addition, besides lunch, we also need to know what type of food these students consumed for supper and breakfast, and what they often eat as the snack. If a student ate home-made food for lunch, but had dinner at KFC regularly, he/she may have the obesity problem. We need to collect the comprehensive information about subjectives' eating habit, not just for the lunch.
These unmeasured confounders may result in the outcome bias. The confounders could influence on both exposure and disease. If a study has too many unmeasured confounders, we would cast doubt on the causality exists between exposure and disease.
What is the study design and how do we know?
Answer: This research is a case- control study because the researchers firstly determined the group of obese (case) and the group of non obese ( control), and then collect the data regarding to the exposure ( eating habits) in each group, to calculate the proportion of the cases (and controls) were exposed and not exposed. Since this study is a case-control study, the researcher calculate the odds ratio to interpret the data.
What are the strengths and weaknesses of the study design?
Answer:
Strengths : This study collect the information of many variables, thus, it decreases the outcome bias by considering many confounders. In addition, the two groups were similar with respect to the age, gender. The similarity may diminish the bias come from the effect of gender and age. Also, this study is cheap and quick.It is not time-consuming and money-consuming.
Weaknesses: Firstly, as mentioned above, this study has many unmeasured confounders. These confounders may lead to bias. Secondly, since it is a case-control study, this research may has the "recall bias". It is possible that the children cannot recall their diet items and amount very clearly, thus causes bias in data. Third, the genetic factors could also lead to obesity. However, in this study, researchers did not collect any data about genetic information. Fourth, the objectives only come from the Midwest communities, and all the subjectives are participants in the health program. This process may cause the "selection bias". The restriction of sample selection might result in the restriction of conclusion.The conclusion can not be generalized to the broad population. Finally, the researchers used the questionnaire to get the data. Because the objectives are children, they may do not answer the questions very seriously. Also, they may lack the health literacy of understanding the question. All of these could lead to the data bias.
Do you agree with the author's interpretation of the findings?
Answer: In general, the outcome of this finding is reliable. So, I agree with the interpretation that the school lunch and watching TV or video games are related to the childhood obesity. However, I think the investigation of school lunch is also very important. If the school lunch is high-calories and low-nutrition, the interpretation of this research may be more persuasive.
Was this responsibly reported in the Internet article?
Answer: Yes, I think the article should be reported on the Internet. Because the research is basically valid, the conclusion of this article should be learned by the general public. In addition, this article will not lead to negative effect to life. After reading this article, more children may bring lunch from home, it would not be a bad thing for the health of children.
What is your impression of this article?
Answer: In general, I think the finding of this article is convictive. Before reading this article, I have known that the school lunch may result in obesity. According to my experience, I gained more pounds when I ate the school lunch. As a contrast, I became slimmer if I ate the home-made food. So, I believe the conclusion of this article. However, it would not be a surprise for me.
Would this change your behavior?
Answer: Yes, this article will remind me the healthy eating behavior. I will try to eat at home and eat in a health way, in order to control my weight.
Should you be alarmed?
Answer: Since the objectives of this research are children, the conclusion may can not be generalized to me. I will tell this finding to my brothers.
What is the value of this article?
Answer: This article may stimulate more researchers to explore the association of obesity and school lunch in other groups, such as the college students. Such researches may help us to deal with the obesity issue.
References:
1.http://www.nytimes.com/2011/02/08/health/research/08childhood.html
2. http://proxy.mul.missouri.edu:2159/science?_ob=ArticleURL&_udi=B6W9H-51NNFHD-12&_user=3419478&_coverDate=12%2F31%2F2010&_rdoc=1&_fmt=full&_orig=gateway&_origin=gateway&_cdi=6683&_sort=d&_docanchor=&view=c&_acct=C000049994&_version=1&_urlVersion=0&_userid=3419478&md5=937b9ae14f722ec7e1ee03d2f288b7dc&searchtype=a&artImgPref=F
3. Gordis, Leon, Case-Control Studies and Other Study Designs, Epidemiology, fourth edition, 2008, 169-177.
I think the obesity is also associated with the peers. If one's friends are overweight, this guy get higher chance of being overweight.
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