BACKGROUND AND PURPOSE:

• As of 2018, US policy requires food retailers to add calorie labels to prepared, ready-to-eat meals
• Petimar et al. (JAMA Internal Medicine, 2022) estimated changes in calories purchased from prepared foods and potential packaged substitutes compared with control foods after calorie labeling of prepared foods in supermarkets 

METHODS:

• Controlled interrupted time series
  • Data came from a supermarket chain
  • Locations: Maine | Massachusetts | New Hampshire | New York | Vermont
• Exposures
  • Pre-labelling policy: April 2015 to April 2017 (2 years)
  • Post-labelling policy: May 2017 to December 2017 (7 months)
• Study design
  • Purchased items were classified as
    • Prepared foods
    • Potential packaged substitutes for prepared foods
    • All other foods (controls)
  • Analyses of prepared and packaged foods were stratified by food category (bakery, entrées and sides, or deli meats and cheeses)
• Primary outcome
  • Mean weekly calories per transaction purchased from prepared foods
• Secondary outcome
  • Mean weekly calories per transaction purchased from similar packaged items (for substitution analyses)

RESULTS:

• 173 supermarkets
• Calorie labeling was associated with mean decreases in prepared bakery and deli items vs control foods
  • Prepared bakery items: –5.1% (95% CI, −5.8 to −4.4)
  • Prepared deli items: –11.0% (95% CI, −11.9 to −10.1)
• No changes seen in calories per transaction with labeling for prepared entrées and sides
  • Mean change 0.3% (95% CI, −2.5 to 3.0)
• Labeling was also associated with mean decreased calories per transaction purchased from packaged foods
  • Packaged bakery items: −3.9% (95% CI, −4.3 to −3.6)
  • Packaged entrées and sides: −1.2% (95% CI, −1.4 to −0.9)
  • Packaged deli items: −2.1% (95% CI, −2.4 to −1.7)
• Absolute decreases in calories purchased
  • Prepared bakery: Approximately 10 calories per transaction
  • Deli items: Approximately 18 calories per transaction
• Results similar regardless of socioeconomic status of supermarket neighborhoods

CONCLUSION:

• Adding calorie labels to prepared foods in supermarkets was associated with small to moderate decreases in calories purchased from prepared bakery and deli items but not entrées or sides
• The prepared items were not replaced with similar packaged items by the customer
• The authors state

To our knowledge, this is the first study to estimate associations of calorie labeling with prepared food purchases in supermarkets

The exploratory analyses suggest that the declines in calories per transaction from prepared bakery and deli items may have been explained by customers purchasing fewer prepared items, rather than switching to lower-calorie items, a pattern also observed in restaurants

These declines may lead to population-level health benefits if they translate to similar changes in consumption

Learn More – Primary Sources:

Assessment of Calories Purchased After Calorie Labeling of Prepared Foods in a Large Supermarket Chain

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