Discussion

The present study is the first to evaluate the extent of competitive food reformulation in response to the implementation of new competitive food standards in middle schools and high schools. The results of the study indicate that product reformulation did play a role in helping schools make nutritional improvements after the competitive foods standards were passed. These product reformulations occurred after and perhaps in response to the competitive food regulations in Massachusetts, as well as potentially in anticipation of the national Smart Snacks law. Reformulation was uncommon among beverages, but a higher percentage of beverages were compliant with state nutrition standards at baseline⁽ Reference Gorski, Cohen and Hoffman ^{12 )}, and since skimmed milk, 100 % juice and plain water were available at baseline these products were not considered reformulated. There were no reformulations of sports drinks and sugar-sweetened beverages, which categorically would not be allowed for sale under the law.

A previous simulation study estimated that reformulating a competitive prepared food could improve students’ diet quality, but it did not measure actual nutritional changes in available foods⁽ Reference Hur, Marquart and Reicks ^{16 )}. Another simulated estimate among adults found that food reformulation may reduce disease-related mortality by up to 5·5 %, indicating its potential to improve the public’s health if used on a broad scale⁽ Reference Leroy, Requillart and Soler ^{17 )}. Reformulated meals have had a positive impact on healthy food consumption for children⁽ Reference Tritt, Reicks and Marquart ^{18 )}, which indicates that this may be one promising strategy for schools trying to increase their compliance with the standards.

Of the foods that were reformulated, 15 % were look-alike versions that were compliant with the standards but were not currently available for sale outside schools. This indicates that food manufacturers were able to successfully respond to strict state nutrition standards by changing the nutrient profile of foods within a short time frame, but these foods were not yet available on the wider market. A recent study found that parents and students cannot distinguish between healthier look-alike items and store versions of the same brands in terms of expected taste or healthfulness, and they have a similar intent to purchase⁽ Reference Harris, Hyary and Schwartz ^{15 )}. Manufacturers of look-alike foods and non-compliant foods are thus able to market to children in schools, potentially encouraging them to establish brand preferences for unhealthy products sold outside school with consumers’ expectations that they would have the same nutritional qualities as the snacks available at schools⁽ Reference Cornwell, McAlister and Polmear-Swendris ^{19 ,} Reference Terry-McElrath, Turner and Sandoval ^{20 )}. Although it is possible that brand preferences established outside school may lead children to purchase the reformulated look-alike versions in school, it is also possible that having these brands available may hurt schools’ credibility when teaching nutrition and wellness because of their association with less healthy versions⁽ Reference Harris, Hyary and Schwartz ^{15 )}. This issue would be avoided if schools sold only new, compliant products or if reformulated versions had clearly different packaging.

Changes to package sizes also helped school districts improve the nutritional quality of competitive foods. Package sizes decreased overall (with nutrient density remaining unchanged); the size of chip bags decreased by 0·13 ounces (3·7 g) between 2012 and 2014. The present data indicate that some foods were repackaged (8·3 % by 2014) to meet the competitive food standards. Many smaller package sizes were available at baseline but became more widely used after the standards were implemented, and these items were thus not counted as repackaged. The decrease in observed package size for beverages demonstrates that this component of the law was effectively implemented (8 fluid ounces (237 ml) for milk and 4 fluid ounces (118 ml) for juice).

Among this sample of Massachusetts schools, the implementation of nutrition standards for competitive foods and beverages was associated with improvements to the nutrient profile of foods and beverages, due in part to food manufacturers reformulating and repackaging products. The findings of this analysis support existing evidence that setting strict nutrition standards can positively impact the nutritional profile of school food⁽ Reference Taber, Chriqui and Chaloupka ^{21 –} Reference Chriqui, Pickel and Story ^{23 )}. This nutritional information expands upon previous research that showed schools had on average 60 % of foods and 78 % of beverages compliant with the nutritional guidelines two years after implementation of the standards⁽ Reference Gorski, Cohen and Hoffman ^{12 )}. Therefore, the nutritional improvements observed in the present study suggest that even imperfect compliance with the law positively impacted the nutritional quality of competitive foods and beverages.

The strengths of the present study include data collection from both pre- and post-implementation of the competitive food law and its two-year follow-up to observe immediate and ongoing response to the policy. The study also has limitations that are important to identify. First, schools in the study may not be racially/ethnically or economically representative of all schools in Massachusetts, and schools in Massachusetts may not be generalizable to the rest of the country. However, in a sensitivity analysis among the few school districts in the study sample that met or exceeded the state percentage of racial/ethnic minority students or students eligible for free/reduced-priced lunch, results for changes in nutritional profile of foods were similar to those in the full sample. The study also did not capture non-packaged competitive food items such as fresh fruits and vegetables because they were served in non-standardized portions. These unpackaged foods were typically sold as part of the school meal programme and were not usually intended to be sold as competitive foods. We also did not capture competitive foods that were sold in the morning for breakfast, although we were able to document competitive foods sold in vending machines that would be available throughout the day. The present study did not analyse data on individual consumption or purchasing behaviour. Previous analyses using NOURISH study data did find decreases in schools’ competitive foods sales. However, students compensated for decreased competitive food purchases by selecting the healthier school meals, which overall is beneficial to both children and schools⁽ Reference Cohen, Gorski and Hoffman ^{13 )}. Future NOURISH studies will examine how product reformulation impacts individual student consumption as well. Lastly, the present study’s estimate of product reformulation is an underestimate of total reformulation, as it only assessed reformulation between 2012 and 2014. It is likely that products were reformulated prior to 2012, especially in light of Massachusetts previously considering competitive foods nutrition standards^{( 10 )}.

Given that the national Smart Snacks standards are very similar to the Massachusetts competitive foods standards, national brands that reformulated products in this sample may reformulate more products to fit national standards. Thus, results of the present study suggest the Smart Snacks in School standards may have a similar impact on the nutritional profile of competitive foods nationwide. Because frequently packaging for reformulated versions of products is very similar to less healthy versions, researchers and state governments should continue to monitor the nutritional quality of competitive foods to ensure that they comply with the competitive foods standards. More broadly, it will also be important to investigate the contribution of competitive foods to children’s overall diet quality, as well as nutritional reforms to other food environments.