Body Size Measurements Grouped Independently of Common Clinical Measures of Metabolic Health: An Exploratory Factor Analysis.

BACKGROUND: Obesity is commonly aggregated with indices of metabolic health. Proponents of body positivity approaches question whether body size is a determinant of health and well-being. Our objective was to conduct an exploratory factor analysis (EFA) to determine if body size measurements factor load with or independent of metabolic health measures. METHODS: The EFA was conducted on n= 249 adults using baseline data from four weight loss trials (Sample 1: n = 40; Sample 2: n = 52; Sample 3: n = 53; Sample 4: n = 104). An EFA of nine items (systolic blood pressure [SBP], diastolic blood pressure [DBP], hemoglobin A1c [HbA1c], HDL-cholesterol [HDL], LDL-cholesterol [LDL], total cholesterol [TC], body mass index [BMI], body fat percent BF%], and waist circumference [WC]) was conducted with oblique rotation. RESULTS: Three factors were retained, which produced a model explaining 87.5% of the variance. Six items loaded strongly (>0.8) under three components and were selected for retention (Factor 1: LDL and TC; Factor 2: BMI and WC; Factor 3: SBP and DBP). CONCLUSION: Body size measures loaded separately from measures of metabolic health and metabolic health were further split into lipid- and blood pressure-focused factors. These results support weight-neutral interventions to improve overall health and well-being.

Evaluation of socioecological factors on health behaviors and weight change during major life event: A cross-sectional study using data collected during the COVID-19 pandemic.

Background: Socioecological factors are associated with key health behaviors that are critical for weight management, and major life events may disrupt engagement in these behaviors. However, the influence of socioecological factors on health behaviors in the midst of major life events is not clear and is difficult to study due to the random and sporadic nature of their occurrence. The COVID-19 pandemic provided a unique opportunity to study a major life event and its impacts on diet, physical activity, and body weight. Objective: This cross-sectional study aimed to investigate associations between socioecological factors (environmental, interpersonal, and individual) and self-reported weight change during a major life event using data collected during the COVID-19 pandemic, and whether the associations were mediated through self-reported changes in eating and physical activity behaviors. Methods: Participants self-reported socioecological factors, weight change, and changes in eating behaviors (EB) and physical activity (PA) via online questionnaires between December 2020 and October 2021. Changes in EB and PA were measured using scales with higher scores reflecting more positive changes during the COVID-19 pandemic. Results: Participants (n = 1283) were mostly female (84.9%) with age 52.1 ± 14.1 years (mean ± SD) and BMI of 32.9 ± 8.2 kg/m2. Stronger healthy eater and exercise identities (individual factors) were associated with higher EB scores (EBS) and PA scores (PAS), respectively (p's < 0.00001). Less discouragement for healthy eating by family/friends (interpersonal factor) was associated with higher EBS (p = 0.002). Higher EBS and PAS were associated with weight loss. The indirect effect of healthy eater identity (-0.72; 95% CI: -0.90, -0.55) and discouragement for diet (0.07; 95% CI: 0.03, 0.12) on weight change through EBS were significant, as was the indirect effect of exercise identity (-0.25; 95% CI: -0.35, -0.15) on weight change through PAS. Conclusions: Stronger identities and less discouragement from family/friends may support health promoting behaviors and weight loss during a major life event, as well as identify additional behavioral targets for lifestyle interventions. Clinical Trial Registration: IWCR was registered at ClinicalTrials.gov (NCT04907396).

Psychometric validation of four-item exercise identity and healthy-eater identity scales and applications in weight loss maintenance.

BACKGROUND: Identifying as someone who engages in health promoting behaviors like healthy eating and exercising may be associated with sustained engagement in those behaviors, but reliable and valid instruments are needed to improve the rigor of this research. Two studies were conducted to (1) examine the psychometric properties of a four-item exerciser identity measure (4-EI) and an adapted healthy-eater identity measure (4-HEI) and (2) examine differences in identity strengths across categories of weight loss success. METHODS: Data from 1,709 community dwelling adults in the International Weight Control Registry (IWCR) were used. A random half of the sample was used to assess the proposed unidimensional factor structure of the 4-EI and 4-HEI and examine convergent and discriminant validity using Spearman rank-order correlations. One-way ANOVA was used in the other random half of the sample to compare 4-EI and 4-HEI scores (-3 to + 3) across three self-defined weight loss categories ('Successful', 'Regain', and 'Unsuccessful') and those maintaining ≥ 5% weight loss for > 1 year vs. not. RESULTS: Results support the unidimensional factor structure with all four items (eigenvalue scores > 2.89) as well as convergent and discriminant validity for both measures. Exercise identity was strongly correlated with self-reported physical activity (r (735) = 0.52, p <.001) and measures of autonomous motivation. Healthy eating identity was moderately correlated with cognitive restraint in eating (r (744) = 0.42, p <.001) and other measures predictive of eating behavior. 4-EI and 4-HEI are stronger in Successful (4-EI: M = 0.90, SD = 1.77; 4-HEI: M = 1.56 SD = 1.37) vs. Regain (4-EI: M=-0.18, SD = 1.68; 4-HEI: M =.57, SD = 1.48) and Unsuccessful (4-EI:M=-0.28, SD = 1.62; 4-HEI: M = 0.51, SD = 1.33) and those maintaining ≥ 5% weight loss (4-EI:M = 0.47, SD = 1.78; 4-HEI: M = 1.13, SD = 1.49) vs. not (4-EI:M=-0.27, SD = 1.66; 4-HEI: M = 0.53, SD = 1.47), p's < 0.001. CONCLUSIONS: The 4-EI and 4-HEI have acceptable psychometric properties and can advance understanding of the role of identity in exercise and dietary behaviors and weight loss maintenance. TRIAL REGISTRATION: The parent observational study, International Weight Control Registry (IWCR), for these sub-studies is registered in ClinicalTrials.gov (NCT04907396).

Weight history of individuals with and without physical disability in the International Weight Control Registry.

Background: People with physical disabilities (PWD) have an increased risk of obesity and related comorbidities compared with people without physical disabilities (PWoD). Previously identified contributors to weight loss maintenance pose challenges to PWD. However, it is not known if PWD experience less success in weight management. Methods: Six hundred and nine participants in the International Weight Control Registry (IWCR) were eligible for this analysis (PWD, n = 174; PWoD, n = 435). Self-reported weight history metrics were compared using general linear models. Perceived weight history category was compared using Chi-squared tests. Importance of diet and physical activity strategies for weight management were compared using Wilcoxon rank-signed tests. Results: PWD reported higher current body mass index (BMI) (36.1 ± 0.7 vs. 31.0 ± 0.5; p < 0.0001) and more weight loss attempts (9.1 ± 0.7 vs. 7.1 ± 0.4; p = 0.01) than PWoD. Current weight loss percentage (PWD 13.0 ± 1.0; PWoD, 13.0 ± 0.6; p = 0.97) and weight loss category (χ 2 [3, N = 609] = 2.9057, p = 0.41) did not differ between the groups. There were no differences in any weight strategy between PWD who were successful and those who regained. Conclusions: PWD and PWoD in the IWCR achieved similar levels of weight maintenance success. However, higher BMI and more weight loss attempts suggest that PWD may face challenges with weight management. More research is needed to identify strategies leading to success for PWD.

Reliability and Validity of the International Physical Activity Questionnaire Adapted to Include Adults With Physical Disability.

BACKGROUND: People with physical disabilities (PWD) participate in less physical activity than people without physical disabilities (PWoD), which increases the risk for several negative health consequences. Comparing physical activity between PWD and PWoD remains a challenge since no reliable and valid survey exists to measure physical activity in both populations. The International Physical Activity Questionnaire (IPAQ) was adapted to be inclusive of PWD using a recently developed survey adaption framework; however, the adapted IPAQ has not been assessed for reliability and validity. The objective of this study was to assess the reliability and validity of the adapted IPAQ. METHODS: To assess test-retest reliability, the adapted IPAQ was completed twice within a 72-hour period by 172 individuals (PWD: n = 102, PWoD: n = 70) and compared using intraclass correlation coefficients. Using Spearman rho, convergent validity and construct validity were assessed in 62 individuals by comparing the adapted IPAQ against the original instrument and activity monitor measured step count, respectively. RESULTS: The adapted IPAQ demonstrated moderate test-retest reliability, with intraclass correlation coefficients of total scores for the total sample of .690 (95% confidence interval [CI] .581-.770) and among subgroup analysis (PWD, .640, 95% CI, .457-.761; PWoD, .758, 95% CI, .610-.850). Correlation coefficients were also good for the assessment of convergent validity of total score (.727; 95% CI, .579-.829; P < .001). Construct validity assessment yielded moderate coefficient (.406; 95% CI, .166-.596; P = .001). CONCLUSIONS: The adapted IPAQ demonstrated acceptable reliability and validity and is appropriate for use in PWD and PWoD.

The Data Behind Popular Diets for Weight Loss.

Both scientific evidence and popular diet trends have sought to identify the ideal diet for weight loss with strategies focused on either restricting carbohydrates or fat. While there is a strong physiologic rationale for either carbohydrate restriction or fat restriction to achieve a calorie deficit needed for weight loss, evidence from randomized controlled trials suggest either type of diet is effective for weight loss. The level of adherence, rather than macronutrient content, is the driver of successful weight loss.

Validating an automated image identification process of a passive image-assisted dietary assessment method: proof of concept.

OBJECTIVE: To validate an automated food image identification system, DietCam, which has not been validated, in identifying foods with different shapes and complexities from passively taken digital images. DESIGN: Participants wore Sony SmartEyeglass that automatically took three images per second, while two meals containing four foods, representing regular- (i.e., cookies) and irregular-shaped (i.e., chips) foods and single (i.e., grapes) and complex (i.e., chicken and rice) foods, were consumed. Non-blurry images from the meals' first 5 min were coded by human raters and compared with DietCam results. Comparisons produced four outcomes: true positive (rater/DietCam reports yes for food), false positive (rater reports no food; DietCam reports food), true negative (rater/DietCam reports no food) or false negative (rater reports food; DietCam reports no food). SETTING: Laboratory meal. PARTICIPANTS: Thirty men and women (25·1 ± 6·6 years, 22·7 ± 1·6 kg/m2, 46·7 % White). RESULTS: Identification accuracy was 81·2 and 79·7 % in meals A and B, respectively (food and non-food images) and 78·7 and 77·5 % in meals A and B, respectively (food images only). For food images only, no effect of food shape or complexity was found. When different types of images, such as 100 % food in the image and on the plate, <100 % food in the image and on the plate and food not on the plate, were analysed separately, images with food on the plate had a slightly higher accuracy. CONCLUSIONS: DietCam shows promise in automated food image identification, and DietCam is most accurate when images show food on the plate.