Investigating the effects of rurality on stress, subjective well-being, and weight-related outcomes.

Purpose: Rates of obesity are significantly higher for those living in a rural versus urban setting. High levels of stress and low levels of subjective well-being (SWB) have been linked to poor weight-related behaviors and outcomes, but it is unclear if these relationships differ as a function of rurality. This study investigated the extent to which living in a rural versus urban county ("rurality") moderated associations between stress / subjective wellbeing (predictors) and diet quality, dietary intake of added sugars, physical activity, and BMI (outcomes). Methods: Participants were recruited from urban (n = 355) and rural (n = 347) counties in Washington State and self-reported psychological, demographic, and food frequency questionnaires while physical activity behavior was measured objectively. Findings: After controlling for relevant covariates, levels of stress were positively associated with added sugar intake for those living in the urban county while this relationship was non-significant for those residing in the rural county. Similarly, SWB was negatively associated with added sugar intake, but only for urban residents. County of residence was also found to moderate the relationship between SWB and BMI. Higher SWB was inversely associated with BMI for those living in the urban county while no relationship was observed for rural county residents. Conclusions: These findings support the hypothesis that the relationships between stress / SWB and weight function differentially based on the rurality of the residing county. This work adds to the growing body of literature highlighting the role stress and SWB play in the rural obesity disparity.

Associations between neighborhood built environment, residential property values, and adult BMI change: The Seattle Obesity Study III.

Objective: To examine associations between neighborhood built environment (BE) variables, residential property values, and longitudinal 1- and 2-year changes in body mass index (BMI). Methods: The Seattle Obesity Study III was a prospective cohort study of adults with geocoded residential addresses, conducted in King, Pierce, and Yakima Counties in Washington State. Measured heights and weights were obtained at baseline (n = 879), year 1 (n = 727), and year 2 (n = 679). Tax parcel residential property values served as proxies for individual socioeconomic status. Residential unit and road intersection density were captured using Euclidean-based SmartMaps at 800 m buffers. Counts of supermarket (0 versus. 1+) and fast-food restaurant availability (0, 1-3, 4+) were measured using network based SmartMaps at 1600 m buffers. Density measures and residential property values were categorized into tertiles. Linear mixed-effects models tested whether baseline BE variables and property values were associated with differential changes in BMI at year 1 or year 2, adjusting for age, gender, race/ethnicity, education, home ownership, and county of residence. These associations were then tested for potential disparities by age group, gender, race/ethnicity, and education. Results: Road intersection density, access to food sources, and residential property values were inversely associated with BMI at baseline. At year 1, participants in the 3rd tertile of density metrics and with 4+ fast-food restaurants nearby showed less BMI gain compared to those in the 1st tertile or with 0 restaurants. At year 2, higher residential property values were predictive of lower BMI gain. There was evidence of differential associations by age group, gender, and education but not race/ethnicity. Conclusion: Inverse associations between BE metrics and residential property values at baseline demonstrated mixed associations with 1- and 2-year BMI change. More work is needed to understand how individual-level sociodemographic factors moderate associations between the BE, property values, and BMI change.

Insights from Washington State's COVID-19 Response: A Mixed-Methods Evaluation of WIC Remote Services and Expanded Food Options Using the RE-AIM Framework.

BACKGROUND: In response to the COVID-19 pandemic, Washington State's Supplemental Nutrition Program for Women, Infants, and Children (WA WIC) adopted federal waivers to transition to remote service delivery for certification and education appointments. WA WIC also expanded the approved food list without using federal waivers, adding more than 600 new items to offset challenges participants experienced accessing foods in stores. OBJECTIVE: This study aimed to assess the reach and effectiveness of the programmatic changes instituted by WA WIC during the COVID-19 pandemic; the processes, facilitators, and challenges involved in their implementation; and considerations for their continuation in the future. DESIGN: A mixed-methods design, guided by the RE-AIM framework, including virtual, semi-structured focus groups and interviews with WA WIC staff and participants, and quantitative programmatic data from WIC agencies across the state. PARTICIPANTS/SETTING: This study included data from 52 state and local WIC staff and 40 WIC participants across the state of Washington and from various WA WIC programmatic records (2017-2021). The research team collected data and conducted analyses between January 2021 and August 2021. ANALYSIS: An inductive thematic analysis approach with Dedoose software was used to code qualitative data, generate themes, and interpret qualitative data. Descriptive statistics were calculated for quantitative programmatic data, including total participant count, percent increase and decrease in participation, percent of food benefits redeemed monthly, and appointment completion rates. RESULTS: All WA WIC participants (n = 125,279 in May 2020) experienced the programmatic changes. Participation increased by 2% from March to December 2020 after WA WIC adopted programmatic changes in response to the COVID-19 pandemic. Certification and nutrition education completion rates increased by 5% and 18% in a comparison of June 2019 with June 2020. Food benefit redemption also increased immediately after the food list was expanded in April 2020. Staff and participants were highly satisfied with remote service delivery, predominantly via the phone, and participants appreciated the expanded food options. Staff and participants want a remote service option to continue and suggested various changes to improve service quality. CONCLUSIONS: Participation in WIC and appointment completion rates increased after WA WIC implemented service changes in response to the COVID-19 pandemic. Staff and participants were highly satisfied with remote services, and both desire a continued hybrid model of remote and in-person WIC appointments. Some of the suggested changes to WIC, especially the continuation of remote services, would require federal policy change, and others could be implemented under existing federal regulations.

Some Ultra-Processed Foods Are Needed for Nutrient Adequate Diets: Linear Programming Analyses of the Seattle Obesity Study.

Typical diets include an assortment of unprocessed, processed, and ultra-processed foods, along with culinary ingredients. Linear programming (LP) can be used to generate nutritionally adequate food patterns that meet pre-defined nutrient guidelines. The present LP models were set to satisfy 22 nutrient standards, while minimizing deviation from the mean observed diet of the Seattle Obesity Study (SOS III) sample. Component foods from the Fred Hutch food frequency questionnaire comprised the market basket. LP models generated optimized 2000 kcal food patterns by selecting from all foods, unprocessed foods only, ultra-processed foods only, or some other combination. Optimized patterns created using all foods contained less fat, sugar, and salt, and more vegetables compared to the SOS III mean. Ultra-processed foods were the main sources of added sugar, saturated fat and sodium. Ultra-processed foods also contributed most vitamin E, thiamin, niacin, folate, and calcium, and were the main sources of plant protein. LP models failed to create optimal diets using unprocessed foods only and ultra-processed foods only: no mathematical solution was obtained. Relaxing the vitamin D criterion led to optimized diets based on unprocessed or ultra-processed foods only. However, food patterns created using unprocessed foods were significantly more expensive compared to those created using foods in the ultra-processed category. This work demonstrates that foods from all NOVA categories can contribute to a nutritionally adequate diet.

Deep learning provides high accuracy in automated chondrocyte viability assessment in articular cartilage using nonlinear optical microscopy.

Chondrocyte viability is a crucial factor in evaluating cartilage health. Most cell viability assays rely on dyes and are not applicable for in vivo or longitudinal studies. We previously demonstrated that two-photon excited autofluorescence and second harmonic generation microscopy provided high-resolution images of cells and collagen structure; those images allowed us to distinguish live from dead chondrocytes by visual assessment or by the normalized autofluorescence ratio. However, both methods require human involvement and have low throughputs. Methods for automated cell-based image processing can improve throughput. Conventional image processing algorithms do not perform well on autofluorescence images acquired by nonlinear microscopes due to low image contrast. In this study, we compared conventional, machine learning, and deep learning methods in chondrocyte segmentation and classification. We demonstrated that deep learning significantly improved the outcome of the chondrocyte segmentation and classification. With appropriate training, the deep learning method can achieve 90% accuracy in chondrocyte viability measurement. The significance of this work is that automated imaging analysis is possible and should not become a major hurdle for the use of nonlinear optical imaging methods in biological or clinical studies.

Inedible Food Waste Linked to Diet Quality and Food Spending in the Seattle Obesity Study SOS III.

Americans waste about a pound of food per day. Some of this is represented by inedible food waste at the household level. Our objective was to estimate inedible food waste in relation to diet quality and participant socio-economic status (SES). Seattle Obesity Study III participants (n = 747) completed the Fred Hutch Food Frequency Questionnaire (FFQ) and socio-demographic and food expenditure surveys. Education and geo-coded tax-parcel residential property values were measures of SES. Inedible food waste was calculated from diet records. Retail prices of FFQ component foods (n = 378) were used to estimate individual-level diet costs. The NOVA classification was used to identify ultra-processed foods. Multivariable linear regressions tested associations between inedible food waste, SES, food spending, Nutrient Rich Food (NRF9.3) and Healthy Eating Index (HEI-2015) scores. Inedible food waste was estimated at 78.7 g/d, mostly from unprocessed vegetables (32.8 g), fruit (30.5 g) and meat, poultry, and fish (15.4 g). Greater inedible food waste was associated with higher HEI-2015 and NRF9.3 scores, higher food expenditures and lower percent energy from ultra-processed foods. In multivariable models, more inedible food waste was associated with higher food expenditures, education and residential property values. Higher consumption of unprocessed foods were associated with more inedible food waste and higher diet costs. Geo-located estimates of inedible food waste can provide a proxy index of neighborhood diet quality.

Characterising percentage energy from ultra-processed foods by participant demographics, diet quality and diet cost: findings from the Seattle Obesity Study (SOS) III.

Higher consumption of 'ultra-processed' (UP) foods has been linked to adverse health outcomes. The present paper aims to characterise percentage energy from UP foods by participant socio-economic status (SES), diet quality, self-reported food expenditure and energy-adjusted diet cost. Participants in the population-based Seattle Obesity Study III (n 755) conducted in WA in 2016-2017 completed socio-demographic and food expenditure surveys and the FFQ. Education and residential property values were measures of SES. Retail prices of FFQ component foods (n 378) were used to estimate individual-level diet cost. Healthy Eating Index (HEI-2015) and Nutrient Rich Food Index 9.3 (NRF9.3) were measures of diet quality. UP foods were identified following NOVA classification. Multivariable linear regressions were used to test associations between UP foods energy, socio-demographics, two estimates of food spending and diet quality measures. Higher percentage energy from UP foods was associated with higher energy density, lower HEI-2015 and NRF9.3 scores. The bottom decile of diet cost ($216·4/month) was associated with 67·5 % energy from UP foods; the top decile ($369·9/month) was associated with only 48·7 % energy from UP foods. Percentage energy from UP foods was inversely linked to lower food expenditures and diet cost. In multivariate analysis, percentage energy from UP foods was predicted by lower food expenditures, diet cost and education, adjusting for covariates. Percentage energy from UP foods was linked to lower food spending and lower SES. Efforts to reduce UP foods consumption, an increasingly common policy measure, need to take affordability, food expenditures and diet costs into account.

A cross-sectional analysis of physical activity and weight misreporting in diverse populations: The Seattle Obesity Study III.

BACKGROUND: In-person assessments of physical activity (PA) and body weight can be burdensome for participants and cost prohibitive for researchers. This study examined self-reported PA and weight accuracy and identified patterns of misreporting in a diverse sample. METHODS: King, Pierce and Yakima county residents, aged 21-59 years (n = 728), self-reported their moderate-to-vigorous PA (MVPA) and weight, in kilograms. Self-reports were compared with minutes of bout-level MVPA, from 3 days of accelerometer data, and measured weights. Regression models examined characteristics associated with underreporting and overreporting of MVPA and weight, the potential bias introduced using each measure and the relation between perceived and measured PA and weight. RESULTS: MVPA underreporting was higher among males and college educated participants; however, there was no differential MVPA overreporting. Weight underreporting was higher among males, those age 40-49 years and persons with obesity. Weight overreporting was higher among Hispanic participants and those reporting stress, unhappiness and fair or poor health. The estimated PA-obesity relation was similar using measured and self-reported PA but not self-reported weight. Perceived PA and weight predicted measured values. CONCLUSION: Self-reported PA and weight may be useful should objective measurement be infeasible; however, though population-specific adjustment for differential reporting should be considered.

Small increments in diet cost can improve compliance with the Dietary Guidelines for Americans.

Adherence to the Dietary Guidelines for Americans (DGA) may involve higher diet costs. This study assessed the relation between two measures of food spending and diet quality among adult participants (N = 768) in the Seattle Obesity Study (SOS III). All participants completed socio-demographic and food expenditure surveys and the Fred Hutch food frequency questionnaire. Dietary intakes were joined with local supermarket prices to estimate individual-level diet costs. Healthy Eating Index (HEI- 2015) scores measured compliance with DGA. Multiple linear regressions using Generalized Estimating Equations with robust standard errors showed that lower food spending was associated with younger age, Hispanic ethnicity, and lower socioeconomic status. Even though higher HEI-2015 scores were associated with higher diet costs per 2000 kcal, much individual variability was observed. A positive curvilinear relationship was observed in adjusted models. At lower cost diets, a $100/month increase in cost (from $150 to $250) was associated with a 20.6% increase in HEI-2015. For higher levels of diet cost (from $350 to $450) there were diminishing returns (2.8% increase in HEI- 2015). These findings indicate that increases in food spending at the lower end of the range have the most potential to improve diet quality.

Obesity and the Built Environment: A Reappraisal.

The built environment (BE) has been viewed as an important determinant of health. Numerous studies have linked BE exposure, captured using a variety of methods, to diet quality and to area prevalence of obesity, diabetes, and cardiovascular disease. First-generation studies defined the neighborhood BE as the area around the home. Second-generation studies turned from home-centric to person-centric BE measures, capturing an individual's movements in space and time. Those studies made effective uses of global positioning system tracking devices and mobile phones, sometimes coupled with accelerometers and remote sensors. Activity space metrics explored travel paths, modes, and destinations to assess BE exposure that was both person and context specific. However, as measures of the contextual exposome have become ever more fine-grained and increasingly complex, connections to long-term chronic diseases with complex etiologies, such as obesity, are in danger of being lost. Furthermore, few studies on obesity and the BE have included intermediate energy balance behaviors, such as diet and physical activity, or explored the potential roles of social interactions or psychosocial pathways. Emerging survey-based applications that identify habitual destinations and associated travel patterns may become the third generation of tools to capture health-relevant BE exposures in the long term.

Consumption Patterns of Milk and 100% Juice in Relation to Diet Quality and Body Weight Among United States Children: Analyses of NHANES 2011-16 Data.

Background: The American Academy of Pediatrics (AAP) has recommended placing limits on the consumption of milk and 100% juice by children. Methods: Consumption data for 9,069 children aged 2-19 years came from three cycles of the nationally representative National Health and Nutrition Examination Survey (NHANES 2011-2016). Beverages were classified into 100% juices, milk (whole, reduced fat, and skim), caloric sugar sweetened beverages (SSB), low calorie beverages (LCB), and drinking water. The Healthy Eating Index 2015 and Nutrient Rich Food Index NRF9.3 were two measures of diet quality. Analyses examined consumption patterns for milk and 100% juice in relation to diet quality, AAP recommendations, and BMI z-scores across time and for different age groups. Results: Intakes of milk and 100% juice declined sharply with age, whereas SSB and water increased. Top quartiles of HEI 2015 and NRF9.3 diet quality scores were associated with higher intakes of water, milk, and 100% juice and with lower intakes of SSB. Lower-income groups drank less skim milk and water and more whole milk and SSB. Only 30% of the children consumed any 100% juice. There was no association between the consumption of milk or 100% juice and BMI z-scores for any age group. Conclusions: Top quartiles of diet quality were associated with more milk, 100% juice, and water, and less SSB. Higher quality diets were associated with lower compliance with the AAP 100% juice recommendations. Compliance with the AAP 100% juice recommendations was not associated with lower body weights. Attempts to limit the consumption of milk and 100% juice by children might have the unintended consequence of increasing consumption of SSB and may have limited value for obesity prevention.

Activity space metrics not associated with sociodemographic variables, diet or health outcomes in the Seattle Obesity Study II.

BACKGROUND: Activity spaces (AS), captured using GPS tracking devices, are measures of dynamic exposure to the built environment (BE). METHODS: Seven days of Global Positioning Systems (GPS) tracking data were obtained for 433 adult participants in the Seattle Obesity Study (SOS II). Heights and weights were measured. Dietary intakes from a food frequency questionnaire were used to calculate Healthy Eating Index (HEI 2010) scores. Linear regression analyses examined associations between AS measures: daily route length, convex hull, and radius of gyration, and diet quality and health outcomes, adjusting for covariates. RESULTS: AS measures did not vary by age, gender, race/ethnicity, or socioeconomic status. AS measures were not associated with diet quality or with self-reported obesity or diabetes. One AS measure, route length (in miles), was associated with being employed, living in the suburbs, and with distance and time commuting to work. CONCLUSION: Spatial mobility studies based on GPS tracking of environmental exposure need to demonstrate a link to relevant health outcomes.

Beverage consumption patterns among 4-19 y old children in 2009-14 NHANES show that the milk and 100% juice pattern is associated with better diets.

BACKGROUND: Patterns of beverage consumption among children and adolescents can be indicative of food choices and total diet quality. METHODS: Analyses of beverage consumption patterns among 8119 children aged 4-19 y were based on the first 24-h recall of the National Health and Nutrition Examination Survey (2009-14 NHANES). Four pre-defined beverage patterns were: 1) milk pattern; 2) 100% juice pattern; 3) milk and 100% juice pattern; and 4) other caloric beverages. Food- and nutrient-based diet quality measures included the Healthy Eating Index 2010. RESULTS: Most children drank other caloric beverages, as opposed to milk (17.8%), 100% juice (5.6%), or milk and 100% juice (13.5%). Drinkers of milk and 100% juice had diets that did not differ from each other in total calories, total and added sugars, fiber, or vitamin E. Milk drinkers consumed more dairy and had higher intakes of calcium, potassium, vitamin A and vitamin D as compared to all other patterns. Juice drinkers consumed more total fruit, same amounts of whole fruit, and had higher intakes of vitamin C as compared to the other consumption patterns. Drinkers of both milk and 100% juice had the highest HEI 2010 scores of all the consumption patterns. CONCLUSIONS: Beverage consumption patterns built around milk and/or 100% juice were relatively uncommon. Promoting the drinking of milk and 100% juice, in preference to other caloric beverages, may be an effective strategy to improve children's diet quality. Restricting milk and 100% juice consumption may encourage the selection of other caloric beverages.

Selective Adsorption of Thiols Using Gold Nanoparticles Supported on Metal Oxides.

Selective capture of thiols from a synthetic hydrogen sulfide containing mixture using supported nanogold materials has been explored for the potential removal of thiols from sour gas production fluids. In this research, TiO2-, Al2O3-, SiO2-, and ZnO-supported gold nanoparticles have been studied for their usage as regeneratable adsorbents to capture CH3SH, C2H5SH, and i-C3H7SH. Au/TiO2 and Au/Al2O3 showed promising properties for removing the thiols efficiently from a gas-phase mixture; however, Au/Al2O3 did catalyze some undesirable side reactions, e.g., carbonyl sulfide formation. It was found that a mild temperature of T = 200 °C was sufficient for regeneration of either Au/TiO2 or Au/Al2O3 adsorbent. The metal oxide mesopores played an important role for accommodating gold particles and chemisorption of the thiols, where smaller pore sizes were found to inhibit the agglomeration/growth of gold particles. The nature of thiol adsorption and the impact of multiple adsorption-desorption cycles on the adsorbents have been studied using electron microscopy, XPS, XRD, GC, and physi/chemiadsorption analyses.

Patterns of early dietary exposures have implications for maternal and child weight outcomes.

OBJECTIVE: This article examines relations between patterns of dietary exposures at 9 months and infant and maternal weight status at 1 year postpartum. METHODS: Participants were part of the Infant Feeding Practices Study II and included 1807 mothers participating through the first year postpartum. All data were self-reported monthly by mothers. Latent class analysis was conducted to identify patterns of infant dietary exposures at 9 months. Factors that predicted dietary pattern class membership were examined including infant sleep and parity. Dietary pattern membership was used to predict child and maternal weight outcomes at 1 year postpartum. RESULTS: Five patterns of dietary exposures were identified, characterized by differences in milk-feeding and solid foods at 9 months: "Breastfed Fruits and Vegetables," "Breastfed Low Variety," "Formula-Fed Fruits and Vegetables," "Formula-Fed Low Variety," and "Mixed High Energy Density." Infants in the Mixed High Energy Density dietary pattern were more likely to be overweight at 1 year. CONCLUSIONS: Dietary classes that capture different combinations of several aspects of infant feeding may be more useful than single dietary predictors, for example, breastfeeding, formula-feeding, or early introduction to solids, to describe differences in infants' early dietary experience and risk for overweight.

Breastfeeding outcome comparison by parity.

OBJECTIVE: Anecdotally, breastfeeding experiences differ between those who have previously nursed an infant and those who are primiparous. This analysis contrasted breastfeeding outcomes between primiparous women and those with previous experience spanning from maternity stay through 6 months postpartum. STUDY DESIGN: A secondary analysis was conducted of data collected in a randomized, controlled trial with mothers and "well" newborns ≥34 weeks of gestation comparing two post-hospital discharge care models. Mothers completed an in-person interview during the postpartum stay and phone surveys at 2 weeks, 2 months, and 6 months where questionnaires related to breastfeeding were completed. All participants intended to breastfeed. Chi-squared and Wilcoxon rank sum tests were used to test for differences between parity groups. Breastfeeding duration by parity group was compared using a Kaplan-Meier plot and a logrank test. A Cox proportional hazards model was used to evaluate the relationship between breastfeeding duration and parity after adjusting for covariates. RESULTS: Among 1,099 mothers available for analysis, 542 (49%) were primiparous. Multiparous mothers had a longer intended breastfeeding duration (median, 9 vs. 6 months; p<0.001). Following delivery, primiparous mothers had a longer median time to first breastfeeding attempt (119 vs. 96 minutes; p<0.001) and were more likely to have eight or fewer feeding attempts in the first 24 hours (33% vs. 44%; p<0.001)). More primiparous women reported early breastfeeding problems (35% vs. 20%; p<0.001) and mixed feeding at hospital discharge (39% vs. 23%; p<0.001) despite reporting less breastfeeding-associated pain during the first week (p=0.04). Multiparous women were more likely to breastfeed through 6 months (p<0.001). In a multivariable Cox model for breastfeeding duration, an interaction existed between intended breastfeeding duration and parity (p=0.006); among those intending to breastfeed for 12 months, multiparous mothers had a significantly lower hazard of stopping breastfeeding (hazard ratio=0.66; p=0.03) than primiparous mothers. CONCLUSIONS: Women who have breastfed previously have significantly different breastfeeding experiences than primiparous women. Pre- and postdelivery breastfeeding support should differentially target primiparous women to improve breastfeeding outcomes.

Bottle-feeding practices during early infancy and eating behaviors at 6 years of age.

BACKGROUND: Evidence suggests an association of breastfeeding with a maternal feeding style (MFS) that is less controlling than formula feeding, which, in turn, may improve a child's self-regulation of eating. This study examines associations of bottle-feeding practices during infancy with MFS and children's eating behavior (CEB) at 6 years old. METHODS: We linked data from the Infant Feeding Practices Study II to the Year 6 Follow-Up, which include 8 MFS and CEB measures adapted from previous validated instruments. Bottle-feeding practices during the first 6 months estimated by using the Infant Feeding Practices Study II were bottle-feeding intensity (BFI), mother's encouragement of infant to finish milk in the bottle, and infant finishing all milk in the bottle. Adjusted odds ratios (aORs) for associations of bottle-feeding practices with MFS and CEB at 6 years old were calculated by using multivariable logistic regressions controlling for sociodemographic characteristics and other feeding practices (N = 1117). RESULTS: Frequent bottle emptying encouraged by mothers during infancy increased odds of mothers encouraging their child to eat all the food on their plate (aOR: 2.37; 95% confidence interval [CI]: 1.65-3.41] and making sure their child eats enough (aOR: 1.62; 95% CI: 1.14-2.31) and of children eating all the food on their plate at 6 years old (aOR: 2.01; 95% CI: 1.05-3.83). High BFI during early infancy also increased the odds of mothers being especially careful to ensure their 6-year-old eats enough. CONCLUSIONS: Bottle-feeding practices during infancy may have long-term effects on MFS and CEB. Frequent bottle emptying encouraged by mothers and/or high BFI during early infancy increased the likelihood of mothers pressuring their 6-year-old child to eat and children's low satiety responsiveness.

Expertise and sexual offending: a preliminary empirical model.

Rehabilitation and treatment perspectives and interventions have concentrated efforts on areas where perpetrators of sexual abuse are deficient, neglecting those where offenders actively seek and strategically plan sexual offence situations and scenarios. Whereas sexual offenders may display deficiencies in some aspects of their lives, there are domain-relevant competencies such as the selection and manipulation of victims, decision making and problem solving, and eluding detection, in which some individuals appear to excel. Semistructured interviews are conducted with 47 male child sexual offenders in New Zealand, and data are analyzed using grounded theory to generate a model of offence-specific decision making. The outcome of the research is a descriptive model of expertise-related competency (ERC) of child sexual offending. The model identifies and emphasizes the variability of knowledge and skill acquisition among offenders.