Validation of Sedentary Behavior Record Instrument as a Measure of Contextual Information of Sedentary Behavior

Background: To establish evidence for the validity of the Sedentary Behavior Record (SBR) instrument using a criterion measure through a proxy of direct observation. Methods: A total of 27 study participants (aged ≥18 y; 15 male) participated in this study. Throughout a 4-day measurement period, each participant recorded their sedentary behavior using the SBR in 10-minute blocks every night. During the measurement period, participants also wore wearable Autographer cameras as a proxy for direct observation. Autographer data were aggregated into 10-minute intervals. To establish evidence of validity, contingency (C) and Kappa (K) coefficients were calculated between the SBR and the Autographer data. For C and K, agreements were determined between 2 measures every cell. The coefficient C was compared across domains, types, and time of day, and K was compared across types of day and times of day. Results: Overall, the coefficients C and K were acceptable (C = .70) and substantial (K = .64), respectively. Among all domains, the highest C was reported for work-related sitting (C = .87). Values of C ranged from .49 to .91 among all activities; the highest accuracy was for work-related, screen-based sitting. Conclusions: This study suggests that the SBR is an acceptable self-report measure of sedentary behavior in adults.

Trends in Ultra-Processed Food Purchases from 1984 to 2016 in Mexican Households

Global trade agreements have shaped the food system in ways that alter the availability, accessibility, affordability, and desirability of ready-to-eat foods. We assessed the time trends of ultra-processed foods purchases in Mexican households from 1984 to 2016. Cross-sectional data from 15 rounds of the National Income and Expenditure Survey (1984, 1989, 1992, 1994, 1996, 1998, 2000, 2002, 2004, 2006, 2008, 2010, 2012, 2014 and 2016) were analyzed. Food and beverage purchases collected in a daily record instrument (over seven days) were classified according to their degree of processing according to the NOVA food framework: (1) Unprocessed or minimally processed foods; (2) processed culinary ingredients; (3) processed foods; and (4) ultra-processed foods. From 1984 to 2016, the total daily energy purchased decreased from 2428.8 to 1875.4 kcal/Adult Equivalent/day, there was a decrease of unprocessed or minimally processed foods (from 69.8% to 61.4% kcal) and processed culinary ingredients (from 14.0% to 9.0% kcal), and an increase of processed foods (from 5.7% to 6.5% kcal) and ultra-processed foods (from 10.5% to 23.1% kcal). Given that ultra-processed foods purchases have doubled in the last three decades and unprocessed or minimally processed foods purchased have gradually declined, future strategies should promote the consumption of unprocessed or minimally processed foods, and discourage ultra-processed foods availability and accessibility in Mexico.

An Examiner-Induced Visual Vigilance Apparatus

A film/record instrument is described that could measure attending behavior, distractibiliry, hyperkinetic movement, and selected aspects of visual perception by recording the subject's response to significant visual stimuli.