Gender, Age, Hunger, and Body Mass Index as Factors Influencing Portion Size Estimation and Ideal Portion Sizes

Differences in Portion Sizes in Brazil, France, and the USA

Portion size is recognized as a major determinant of food intake, at least over the short term, and could be related to overconsumption and obesity. In this study, we developed and evaluated a new visual measure of portion size (PS), examined whether the PS of chicken, ice cream, and soda varied among people in Brazil, France, and the USA, and tested whether PS was related to gender, body mass index, body weight, and socioeconomic status. We conducted a cross-sectional study using online convenience samples of university students (total N = 1391). Across all three foods, French personal and country PSs were significantly smaller than the other three countries. Estimated country PS was reliably larger than personal PS. Women's personal PSs were smaller than men's, but women's and men's estimates for country PS were similar. French personal and country PSs were the lowest. Some PSs had a weak but significant correlation with SES but were not significantly related to either weight or BMI. The study confirms French-American differences in personal PS and demonstrates that perceived norms correspond to individual PS.

Considerations for a protein-focused screening instrument in clinical nutrition assessment

Physiological stress during injury and surgery negatively impacts protein balance and muscle mass maintenance. Adequate perioperative protein intake may attenuate muscle atrophy to maintain and facilitate functional recovery, particularly in older adults; yet, screening tools routinely used in clinical settings do not specifically assess protein intake when assessing nutrition risk. Although assessing malnutrition is a priority, suboptimal protein intake in non-malnourished patients should also be identified given protein's critical role in muscle health. This opinion paper highlights the potential for using a clinically appropriate protein-focused screener for rapid and efficient characterization of protein intake.

Development and validation of an online tool to assess perceived portion size norms of discretionary foods

BACKGROUND

Perceived portion size norms (typical perception of how much of a given food individuals choose to eat at a single occasion) may have shifted towards larger sizes due to the ubiquity of large serving sizes. However, there is a lack of validated tools to assess such norms for energy-dense and nutrient-poor discretionary foods. This study aimed to develop and validate an online tool to examine the perceived portion size norms of discretionary foods.

METHODS

An online image-series tool of 15 commonly consumed discretionary foods was developed, with eight successive portion size options included for each food. Using a randomised-crossover design, adult consumers (18-65 years) completed the validation study in a laboratory session (April-May 2022) by reporting their perceived portion size norms for each food twice, once based on food images on a computer and another time based on equivalent real food portion size options at food stations in the laboratory. Agreement between methods for each test food was examined using cross-classification and intra-class correlation (ICC).

RESULTS

A sample of 114 subjects were recruited (mean age 24.8 years). Cross-classification indicated >90% of selections were matched in the same or adjacent portion size option. ICC was 0.85 across all foods, demonstrating a good level of agreement.

CONCLUSION

This novel online image-series tool developed to examine perceived portion size norms of discretionary foods showed good agreement with equivalent real food portion size options and may be valuable to investigate perceived portion size norms of common discretionary foods in future studies.