1Other studies have examined the effects of price reductions, increases in availability, and promotion of low-fat foods in secondary schools on sales and purchases of these foods (French et al 2004, 2001, 1997a, 1997b, Jeffery et al 1994) as well as their consumption (Perry et al 2004) within experimental settings and found positive effects.
2Kubik et al (2003) find that a la carte availability in school is negatively associated with overall intake of fruits and vegetables and positively associated with total and saturated fat intake among 7th graders attending 16 Minneapolis-St Paul schools. Using the same data, Kubik et al (2005) show that using competitive foods as rewards and incentives is positively associated with BMI.
3Also, using the ECLS-K, Fernandes (2008) found small positive associations between soda availability in schools and both in-school and overall soda consumption of fifth graders.
4Their results for the other school policies, pouring rights contracts, and food and beverage advertisements are smaller and less precise.
5For example, California’s first nutrition policy (SB 677) implemented beverage standards for elementary and middle schools, not high schools.
6All sample sizes have been rounded to the nearest 10 per the ECLS-K’s restricted-use data agreement.
7Obesity is defined as BMI greater than the 95th percentile for age and gender on the Center for Disease Control growth charts.
8Sweets include candy, ice cream, cookies, brownies or other sweets; salty snack foods include potato chips, corn chips, Cheetos, pretzels, popcorn, crackers or other salty snacks, and sweetened beverages include soda pop, sports drinks or fruit drinks that are not 100 percent juice.
9To validate the ECLS-K estimates, we examined the Third School Nutrition and Dietary Assessment Study (SNDA-III), which collected 24-hour dietary recall from 2,300 children attending a nationally representative sample of public schools in 2005. Similar to the ECLS-K, eighty percent of elementary school children reported no competitive food purchases. Among children who made a purchase, the median daily caloric intake from these foods was 185 calories. The SNDA estimate is higher than our ECLS-K estimates (62 calories reported in Section 5) because it includes healthy foods purchased from competitive food venues: for example, milk was by far the most popular item purchased from competitive food venues and yogurt also ranked highly.
10The “potatoes” category excluded French fries, fried potatoes, and potato chips.
11The questionnaire separately asked about availability of high- and low-fat options for baked foods, salty snacks, and ice cream/frozen yogurt/sherbert. We include both the low- and high-fat options in our measure, however, in sensitivity analyses, we used only the high-fat versions to construct our school-administrator based measure of junk food availability and found results to be similar.
12We rely mainly on the first measure of junk food availability because it is the most specific with respect to the quality of foods and because school-level policies regarding junk food availability are frequently set by school principals and staff (Gordon et al 2007a). We prefer this measure over the simple dichotomy of having any (unregulated) competitive food outlets because the outlet-based measure does not differentiate the type of foods sold (e.g. milk vs. soda). We also prefer it over the child-report because children who do not consume junk foods are less likely to accurately report availability and because children reported only the availability of any sweets, salty snacks, or sweetened beverages, but did not differentiate specific items (e.g. low-fat vs. high-fat).
13The value of reduced form regressions has been highlighted by Angrist and Krueger (2001) and, more recently, Chernozhukov and Hansen (2008) formally show that the test for instrument irrelevance in the reduced form regression can be viewed as a weak-instrument-robust test of the hypothesis that the coefficient on the endogenous variable in the structural equation is zero.
14This literature examines peer effects on a wide range of outcomes including substance use (Lundborg 2006; Eisenberg 2004; Case and Katz 1991; Gaviria and Raphael 2001), crime (Case and Katz 1991; Glaeser, Sacerdote, and Scheinkman 1996; Regnerus 2002), teenage pregnancy (Crane 1991; Evans, Oates and Schwab 1992), discipline (Cook et al 2008), academic achievement (Hanushek et al 2003; Cook et al 2008), adolescent food choices (Perry, Kelder, Komro 1993; Cullen et al 2001; French et al 2004) and weight (Trogdon, Nonnemaker and Pais 2008).
15However, Clark and Loheac (2007) estimate how substance use behavior of students within the same school who are one year older influences adolescent substance use and find a positive relationship.
16One exception is Eisenberg (2004) who finds that 7th and 8th graders who attend schools with older peers are no more likely to use substances relative to those who attend schools with younger peers.
17We also examined unadjusted differences in children’s individual, family and school characteristics during the 5th grade (see Appendix Table A3). There were slight differences for some of the covariates. However, there was no overall pattern in the socioeconomic factors that would threaten the validity of the IV approach: that is, some differences imply better BMI outcomes for one group and others worse. For example, in our sample, elementary school students are more likely to be Hispanic and Asian while combined school students are more likely to be white. There are no differences in the share that are Black. Similarly, there is no consistent pattern in maternal education. Elementary school students are more likely to have poorly and highly educated mothers (less than high school, more than Bachelors).
18To check whether these null findings are merely due to lack of power instead of absence of peer effects, we estimated the same models using social-behavioral outcomes and test scores as dependent variables because the literature finds evidence of peer effects on these outcomes. We were able to identify statistically significant peer effects on social-behavioral outcomes (but not test scores), which suggests that lack of power is an unlikely explanation for the finding of null peer effects on BMI and related outcomes.
19In all models, we estimate robust standard errors clustered at the school level.
20In alternate analyses, we used continuous measures of the highest and lowest grades in the school as instruments. In these over-identified models, both instruments had a strong positive association with junk food availability (i.e. increases in the highest and lowest grades available at the school were strongly predictive of junk food availability). This approach yielded qualitatively similar results as the exactly-identified models (available upon request).
21The IV regressions were also estimated without baseline BMI. The point estimates, first-stage F-statistics, and Hausman tests yield similar results (available upon request).
22A concern with our IV specification estimated via two-stage least-squares is that our first stage models do not account for the dichotomous nature of the treatment variable (Maddala 1983). Estimates from binary treatment effect IV models confirm that the effects of junk food availability on BMI are neither substantive nor significant (available upon request).
23We also conducted additional sensitivity analyses not reported here. First, given that we do not know the exposure to junk food in previous grades and given concerns that genetic susceptibility may not have a constant proportional effect on BMI at every point in the life cycle, we controlled for 1st or 3rd grade BMI instead of BMI in Kindergarten and obtained similar results. Second, inclusion of controls for school meal participation did not change our findings. Third, we used BMI z-scores as the dependent variable to accurately control for age and gender influences on BMI and obtained qualitatively similar results. Fourth, we estimated quantile regressions to test whether the effects of junk food availability varied across the BMI distribution, but found no evidence for heterogeneous effects. Finally, we also re-estimated our BMI and obesity models separately for each gender. The results for junk food availability mirrored those for the full sample. The OLS, IV, and RF models show no significant effects of junk food availability for either boys or girls. Still we may be concerned about differential peer effects, for example, if girls are influenced by older peers’ concerns about body image, which would bias our IV estimates downward. Restricting the sample to those boys and girls attending schools without junk food availability, the coefficients from the reduced form were nearly identical to those based on the full sample of boys and girls, which suggests that peer effects are not an issue even when regressions are gender-specific.
24Estimates based only on the sample of private schools yield small and statistically insignificant effects of competitive food availability on BMI in both OLS and IV specifications, although the F-statistics for the instrument in the first stage were smaller (Results available upon request).
25Hausman tests cannot reject the consistency of fully-specified OLS estimates in any of our sensitivity checks.
26Although not shown, the IV (Wald) estimates are easily calculated by dividing the reduced form estimates in Table 10–Table 12 by 0.2 (first stage estimate from Table 2). The IV coefficients are never significant in part due to the larger standard errors in the regressions of reported eating behaviors and physical activity.
27We dichotomize the in-school purchase variables and estimate linear probability models since much of the variation in junk food purchases at school occurs on the extensive margin.
28The median number of times an item is purchased in school among children who purchase at least once is 1.5 times (1–2 times per week). We assume that salty snacks add 140 calories (typical calories from a bag of potato chips), sweets add 200 calories (typically calories from a candy bar), and soda adds 150 calories. Given the limitations of the consumption data in the ECLS-K, we caution the reader to treat these caloric intake calculations as approximations.
29Discretionary calories are the difference between an individual’s total energy requirement and the energy necessary to meet nutrient requirements. According to Dietary Guidelines for Americans, the discretionary allowance for a 2000 calorie diet is 267 calories. See: http://www.health.gov/dietaryguidelines/dga2005/document/html/chapter2.htm#table3 accessed August 22, 2008.
30The total consumption variables are not dichotomized because there is sufficient variation on the intensive margin.
31Negative binomial models with a binary treatment variable to account for the count-data distribution of the total consumption variable and the binary nature of junk food availability produced qualitatively similar results. (Results available upon request).
32Given the limitations of the ECLS-K’s consumption variables, we again examined the SNDA-III data and found no evidence that combined school attendance increases total caloric intake.
33“Schools expect budget cuts as economy sours: State problems, decline in property values eat away at district funds”. Available at: http://www.msnbc.msn.com/id/23116409/ (Accessed February 10, 2009).
Since the alarming struggle our nation has had with childhood obesity, many have voiced their opinion, and ideas on what should be done to subside obesity rates. In 2006 Lisa Belkin voiced her opinion on school lunches in her article “The School Lunch Test”. In her article Lisa summarize different associations that where made to better the school lunches in America. Lisa goes though the pros and cons of the different associations and there solutions to make healthy nutritional school lunches. It goes to show that the United States was looking for the best solution to make American youths healthy.
In 2012 Michelle Obama came up with a solution, and formed the Child Nutrition Bill. In “The Bill We Need” she voices her plan for the solution to make a huge change in child hood obesity through school lunches. Michelle explains the power this bill has to make a difference, and all the support she has gotten for the bill to pass. She proclaims with the passing of the bill our country has an opportunity to make a change to significantly better the health of youth America. With this solution it will set high nutrition standards for schools to meet, and will reward those schools for meeting those new high standards. She explains kids enrolled in the NSLP (Nation School Lunch Program) will get the nutrition they need to exceed. Early in her article she explains that African America, Latino, and Native Americans are the most at-risk for child hood obesity. Which are also the minorities most likely to be enrolled with the NSLP to receive free or reduced –priced school lunches. Michelle states “if we work together and each do our part, I'm confident that we can give our children the opportunities they need to succeed, and the energy, strength and endurance to seize those opportunities.”(Obama 11). Furthermore with any new bill or solution there is always going to be controversy.
In 2013 Von Diaz wrote an article called “What Ever Happened to Michelle Obama’s School Lunch Program?” about the controversy over Michelle Obama’s new school lunch program. Von talks about some of the students and schools who have protested or ridiculed Michelle Obama’s program, and who have even dropped the program. He explains that what he has come to find is that most of the school districts that have discriminated against the program were majority Caucasian, who majority of the students are not served by the NSLP (Nation School Lunch Program). That in the new lunch program the majority of students receiving free or reduced priced lunch served by the NSLP are of color. The school districts with diversity Von has come to find that there positive voices about the new program are not being heard. Those districts support the program and believe It will make a change. Von interviewed Sal Valenze of the West New York District and he states in Von’s article ““If you look at it, taking a kid who’s a senior in high school, and changing his eating habits in one year—there’s going to be resistance there. But we’re raising the kids through this program. It becomes the culture of the way they eat, and they will be healthier in the long run.””(Diaz 15).
Belkin, Lisa “The School-Lunch Test” The New York Times. 20 August 2006. Web. 30 October 2013A couple years ago Lisa Belkin wrote the article “The School-Lunch Test” in the The New York Times. Even though her article is a little bit out of date (about seven years ago) it still holds relevance if one wishes to find information on the attempts to make school-lunches in the United States more healthy for students. Most of her article Belkin summarizes the ideas tested by multiple groups within the United States that essentially all have the same motive of solving the school-lunch issue (1
The first group she mentions is HOPS (Healthier Options for Public Schoolchildren) which was started by Dr. Arthur Agatston who founded the “South Beach Diet”. This program essentially uses the foods that Dr. Agatston produce in his diet plans and places them in selected school districts for studying purposes (1). The main goal being to figure out if there is solution to the school-lunch problem. Another group that Belkin mentions is HOPE (Healthy Options for People through Extensions). Its main goals are to make nutrition through the education processes at the schools that have this program (2).
The main problems that these two groups have when fixing the problem of school-lunches are also covered by Belkin. She mentions that staff at schools are hard to ease into the solution due their current relationships with food (8). She also goes on to say parents are to blame as well, some wondered “why their children were being put on the South Beach Diet” (8). Both groups propose solutions to help with the problems holding them back from producing healthy foods in schools. One solution is to “persuade donors and school boards and governments and entities that better food is worth the cost” (10). And to back this up she goes on to state that “the overweight rate in the HOPS schools in fact declined during the 2005-6 school year” (11). Belkin writes about a good topic and quotes and sites a lot of people and statistics that really make the reader feel like this proposed solution could actually have very beneficial effects for the American youth.
Obama, Michelle. “Food Bill We Need” The Washington Post. 2 August, 2012.WebMichelle Obama wrote the article “The Bill We Need” published in the Washington Post, to essentially gain support from our country on passing The Child Nutrition Bill. She starts off the article describing how 5th grade students from a new by school came to the White House to help start the very first garden for the kitchen. She mentions the enlighten conversation she had with those students on how big of a role food plays in with living healthy lives. That conversations was essentially her inspiration to make a change, and to form The Child Nutrition Bill. She informs her readers how for years the nation has struggled with the epidemic of obesity, and the highest obesity statistics are among African American, Hispanic, and Native Americans. She states “We've seen the cost to our economy -- how we're spending almost $150 billion every year to treat obesity-related conditions. And we know that if we don't act now, those costs will just keep rising.”(2).
Michelle explains that with our nations concern on childhood obesity a nationwide campaign “Lets Move” was formed. She explains that with this campaign it helps parents and communities get the information they need for a healthy life style. She states that even with the support of parents leading a healthy life style at home, she need the schools to lead the healthy life style also. She mentions “The last thing parents need or want is to see the progress they're making at home lost during the school day.”(5). with that she proclaims with the pass of this bill our country has an opportunity to make a change to significantly better the health of kids.
Michelle goes on to explain what this bill has the power to bring the change everyone wants. With this bill it will bring fundamental change to schools to allow for more healthy food options. It will set high nutrition standard or schools to meet by requiring more fruits, vegetables, and whole grains. Which will overall reduce fat and salt intake. With this bill Michelle explains it will eliminate junk food from vending machines, and a la carte lines. Kids enrolled in the National School Lunch Program will get the nutrition they need to exceed. She explains all the community leaders, stakeholders, parents, teachers, school board members, and principals she has met with on this issue, and how they all know how important it is for this nutritional change. Michelle pleads how important it is for congress to pass this bill. At the end of her article she says “if we work together and each do our part, I'm confident that we can give our children the opportunities they need to succeed, and the energy, strength and endurance to seize those opportunities.”(11).
Diaz,Von. “What Ever Happened to Michelle Obama’s School Lunch Program?”Colorlines.com. 9 September 2013In This Latest “What Ever Happened to Michelle Obama’s School Lunch Program?” article Von goes to explain since the congressional majority passed Michelle Obama’s program it has undergone some serious discrimination. Some individual students have protested the new school lunched by making various videos. School districts in some states such as California, New York, Texas have dropped the program simply because students were not eating or purchasing the healthier foods; causing schools to lose money. Von states that the vast majority of the school lunch eaters served by the NSLP (Nation School Lunch Program) voices are not being heard. He explains that the majority of the kids on the NSLP receiving free or reduced school lunches are African American, Latino, or Native American children wish are most at risk of childhood obesity. Von states “Schools that serve children of color, who are at much higher risk of childhood obesity than white children, have been conspicuously missing from the debate and experts say the opposition could negatively impact the NSLP in the long run.”(4).
Von has come to find that most school districts that have dropped the program have predominantly white population of students, and very low percent of students receiving free or reduced- price lunches. The GAO (Government Accountability Office) showed a recent study that some students don’t like the new healthy, and smaller proportion lunches stopped purchasing them, which led to some schools losing food funding. The producer of the study Kay Brown stated in this article “I think it’s fair to say in the sites where more kids are paying full lunch price, there is a probably a greater risk that they may take issue with the changes.” Brown says.”(10).
Von explains in depth how children of color are demographic served by the NSLP, and how there the most at risk. He states that the NSLP is important for children that come from low income. That most school districts with diversity who serve a high population of free or produced- prices lunches don’t complain. Have actually had positive feedback from the students about the new healthy food. Sal Valenze of the West New York School District sates in this article ““Over time, these changes are going to have a change on the youth of America,” Valenza says. “If you look at it, taking a kid who’s a senior in high school, and changing his eating habits in one year—there’s going to be resistance there. But we’re raising the kids through this program. It becomes the culture of the way they eat, and they will be healthier in the long run.””(15). Von suggest at the end of his article that the colored population that is most served by the NSLP should have the largest role in shaping the future of this program.