Addressing Challenges with the Categorization of Foods Processed at Home: A Pilot Methodology to Inform Consumer-Facing Guidance

The degree of food processing contributes to sugar intakes in families with preschool-aged children

BACKGROUND AND AIMS

Evidence implicates ultra-processed food intake as a major contributor of excess dietary sugars. However, little research exists on the relationship between the degree of food processing and sugar intake in families with young children. We investigated associations between the degree of food processing and sugar intake (total and free sugars) in Canadian preschool-aged children and parents.

METHODS

This cross-sectional study of 242 families included preschool-aged children (n = 267) and parents (n = 365) participating in the Guelph Family Health Study. Dietary intake was assessed via the web-based Automated Self-Administered 24-h Dietary Assessment Tool (ASA24-Canada-2016) and classified according to the NOVA Food Classification System including, unprocessed or minimally processed foods, processed culinary ingredients, processed foods and ultra-processed foods. Linear regression models with generalized estimating equations were used to examine associations between the energy contribution of each NOVA classification category and sugar intake (% kcal of total and free sugars). Pearson correlation coefficient estimates were used to assess dietary relationships between parents and children.

RESULTS

Ultra-processed foods were the greatest source of energy (44.3%) and energy from total (8.7%) and free sugars (7.3%) in the parents' diets, and the greatest source of energy (41.3%) and energy from free sugars (7.6%) in the children's diet. Ultra-processed food intake was positively associated with sugar intake in parents (total sugars: B = 0.05, 95% CI: 0.02-0.09, p = 0.01; free sugars: B = 0.11, 95% CI: 0.08-0.15, p < 0.001) and children (total sugars: B = 0.10, 95% CI: 0.04-0.16, p = 0.001; free sugars: B = 0.16, 95% CI: 0.12-0.21, p < 0.001). Unprocessed or minimally processed food intake was negatively associated with free sugar intake in parents (B = -0.08, 95% CI: -0.12 to -0.05, p < 0.001) and children (B = -0.15, 95% CI: -0.19 to -0.10, p < 0.001). Weak correlations were found between parents and children for processed culinary ingredients and ultra-processed processed food intake (p < 0.001).

CONCLUSIONS

This study highlights the associations between degree of food processing and sugar intake in parents and children, whereby ultra-processed foods were positively, and unprocessed or minimally processed foods were negatively, associated with sugar intake. These are important considerations in the development of policy and recommendations for foods to potentially promote or limit.

Consumption of highly processed foods in relation to overall diet quality among Japanese adults: a nationwide study

OBJECTIVE

To (i) examine the consumption of highly processed foods (HPF) in relation to diet quality among Japanese adults and (ii) compare the results when dishes prepared away home are disaggregated into food ingredients before classification by processing levels and the results when they are not.

DESIGN

Cross-sectional analysis using 4-day dietary record data. Foods were categorised by level of processing using the framework developed by the University of North Carolina at Chapel Hill. Specifically, dishes prepared away from home were classified at both the food level (classified after disaggregation into ingredients) and dish level (classified without disaggregation). Diet quality was assessed using the Healthy Eating Index-2015 and Nutrient-Rich Food Index 9·3.

SETTING

Twenty areas in Japan.

PARTICIPANTS

Adults aged 20-69 years (n 388).

RESULTS

Energy contribution of HPF was higher when dishes prepared away from home were classified at dish level than food level (48·3 % v. 32·9 %, P < 0·0001). Regardless of the classification method, cereals and starchy foods were the top food groups contributing to total energy intake from HPF. After adjusting for potential confounders, participants in higher tertiles of the energy contribution of HPF had lower total scores for Healthy Eating Index-2015 and Nutrient-Rich Food Index 9·3 (P for trend ≤ 0·007 for all), irrespective of the food- or dish-level classification.

CONCLUSIONS

HPF accounted for at least one-third of energy intake of Japanese adults. Regardless of the classification methods for dishes prepared away from home, higher consumption of HPF was associated with lower diet quality.

Highly Processed Food Consumption and Its Association with Anthropometric, Sociodemographic, and Behavioral Characteristics in a Nationwide Sample of 2742 Japanese Adults: An Analysis Based on 8-Day Weighed Dietary Records

This cross-sectional study assessed highly processed food (HPF) consumption and its association with individual characteristics in a nationwide sample of Japanese adults. Eight-day weighed dietary records were obtained from 2742 free-living adults aged 18-79 years across Japan. HPFs were identified based on a classification method developed by researchers at the University of North Carolina at Chapel Hill. The basic characteristics of the participants were assessed using a questionnaire. On average, HPF contributed to 27.9% of daily energy intake. The contribution of HPF to the daily intake of 31 nutrients ranged from 5.7% for vitamin C to 99.8% for alcohol (median, 19.9%). Cereals and starchy foods were the main food groups that contributed to the total energy intake of HPF. Multiple regression analysis showed that the older group (60-79 years) had a lower HPF energy contribution than the younger group (18-39 y) (regression coefficient (β) = -3.55, p < 0.0001). Compared to current smokers, past and never-smokers had lower HPF energy contributions (β = -1.41, p < 0.02; and -4.20, p < 0.0001, respectively). In conclusion, HPFs account for approximately one-third of energy intake in Japan. Younger age and current smoking status should be considered in future intervention strategies to reduce HPF consumption.

The degree of food processing is associated with anthropometric measures of obesity in Canadian families with preschool-aged children

Adopting a healthy diet remains central for the prevention of obesity. In adults, higher intake of ultra-processed food is associated with a greater risk of overweight and obesity. However, little is known about the degree of food processing and its association with anthropometric measures in families with preschool-aged children, a critical period for the development of dietary patterns. This cross-sectional study included preschool-aged children (n = 267) between 1.5 and 5 years of age and their parents (n = 365) from 242 families enrolled in the Guelph Family Health Study. Dietary assessment was completed using ASA24-Canada-2016. Foods and beverages were classified based on their degree of food processing using the NOVA Classification (unprocessed or minimally processed foods, processed culinary ingredients, processed foods, and ultra-processed foods). Associations between the energy contribution (% kcal) of each NOVA category and anthropometric measures were examined using linear regression models with generalized estimating equations, adjusted for sociodemographic variables. The energy contribution of ultra-processed foods was the highest relative to the other NOVA categories among parents (44.3%) and children (41.3%). The energy contribution of unprocessed or minimally processed foods was 29.1% for parents and 35.3% for children, processed foods was 24.0% for parents and 21.3% for children, and processed culinary ingredients was 2.6% for parents and 2.1% for children. Ultra-processed foods (% kcal) were positively associated with BMI (β = 0.04, 95% CI: 0.01–0.07, P = 0.02), waist circumference (β = 0.11, 95% CI: 0.03–0.18, P = 0.008) and body weight (β = 0.13, 95% CI: 0.03–0.22, P = 0.01) in parents, but not children. Unprocessed foods (% kcal) were negatively associated with waist circumference in parents (β = −0.09, 95% CI: 0.18–0.01, P = 0.03) and children (β = −0.03, 95% CI: 0.05–0.01, P = 0.01), as well as body weight (β = −0.12, 95% CI: 0.23–0.00, P = 0.04) in parents. The degree of food processing primarily influenced anthropometric outcomes in parents. Nevertheless, diets of children were similar, suggesting that such exposure in families may eventually lead to outcomes observed in parents.

Definitions and Assessment Methods of ‘Home Cooking’ in Studies with Dietary Variables: A Scoping Review

Home cooking is a complex idea that involves multiple skills and behaviors and can be interpreted differently. Using six databases (two of which were Japanese), this scoping review examined the definitions and methods used in studies investigating the relationship between home cooking and dietary variables. Of the 40 studies (2 in Japanese) included in this review, 8 provided definitions but did not specify the extent or level that convenience foods can be allowed in food preparation. The methods were classified into two categories, namely, perception-dependent (n = 29) if using a self-reported instrument, or perception-independent (n = 11) if based on investigators’ classification. Subsequently, indicators of home cooking were classified based on survey attributes (e.g., frequency, location). All but five studies used single indicators, primarily the preparation frequency (n = 18). Quality of analysis was also evaluated. Studies that used multiple indicators or perception-independent methods showed high or moderate overall quality. In contrast, studies that used single indicators based on perception-dependent methods tended to have a low overall quality. The consistency of the relationship between home cooking and dietary variables depended on study quality. In conclusion, the definitions of home cooking were inconsistent across studies, and lacked consensus for examining the association between dietary outcomes.