BACKGROUND: Cooking at home has been promoted as a strategy to improve diet quality; however, the association between cooking behavior and ultra-processed food intake is unknown.
OBJECTIVE: The objective of this study was to examine associations between frequency of cooking dinner at home and time spent cooking dinner with ultra-processed food intake.
DESIGN: Cross-sectional, nationally representative data from the 2007-2010 National Health and Nutrition Examination Survey were analyzed.
PARTICIPANTS/SETTING: Participants were 9,491 adults (20 years and older) in the United States.
MAIN OUTCOME MEASURES: The main outcome measure was the proportion of energy intake (averaged from two 24-hour dietary recalls) from the following 4 Nova food-processing groups: (1) unprocessed or minimally processed foods, (2) processed culinary ingredients, (3) processed foods, and (4) ultra-processed foods.
STATISTICAL ANALYSES PERFORMED: Separate linear regression models examined associations between cooking frequency and time spent cooking dinner and proportion of energy intake from the 4 Nova food-processing groups, adjusting for sociodemographic characteristics and total energy intake.
RESULTS: Ultra-processed foods comprised >50% of energy consumed independent of cooking frequency or time spent cooking. Higher household frequency of cooking dinner and greater time spent cooking dinner were both associated with lower intake of ultra-processed foods (P trends < .001) and higher intake of unprocessed or minimally processed foods (P trends < .001) in a dose-response manner. Compared with cooking 0 to 2 times/wk, adults who cooked dinner 7 times/wk consumed a mean of 6.30% (95% CI -7.96% to -4.64%; P < .001) less energy from ultra-processed foods. Adults who spent more than 90 minutes cooking dinner consumed 4.28% less energy from ultra-processed foods (95% CI -6.08% to -2.49%; P < .001) compared with those who spent 0 to 45 minutes cooking dinner.
CONCLUSIONS: Cooking at home is associated with lower consumption of ultra-processed foods and higher consumption of unprocessed or minimally processed foods. However, ultra-processed food intake is high among US adults regardless of cooking frequency.
