Appendix.

Question wording for diet quality measures in the National Health and Nutrition Examination Survey (NHANES)

Measure	Question wording in NHANES
Meals not prepared at home	‘How many meals did you get that were prepared away from home in places such as restaurants, fast food places, food stands, grocery stores, or from vending machines?’
Fast food	‘How many of those meals did you get from a fast-food or pizza place?’
Ready-to-eat meals	‘During the past 30 days, how often did you eat “ready to eat” foods from the grocery store?’
Frozen meals	‘During the past 30 days, how often did you eat frozen meals or frozen pizzas?’