Background

The United States Department of Agriculture’s Supplemental Nutrition Assistance Program (SNAP) is the country’s largest nutrition assistance program for low-income populations. Although SNAP has been shown to reduce food insecurity, research findings on the diet quality of program participants are inconsistent.

Objective

This study evaluated whether the community food environment is a potential moderator of the association between SNAP participation and eating behaviors.

Design

This cross-sectional study used participant data from a telephone survey of 2,211 households in four cities in New Jersey. Data were collected from two cross-sectional panels from 2009 to 2010 and 2014. Food outlet data were purchased from commercial sources and classified as supermarkets, small grocery stores, convenience stores, or limited service restaurants.

Participants/setting

Analysis is limited to 983 respondents (588 SNAP participants) with household incomes below 130% of the federal poverty level.

Main outcome measures

Eating behaviors were assessed as frequency of consumption of fruit, vegetables, salad, and sugar-sweetened beverages.

Statistical analyses performed

Interaction and stratified analyses using gamma regression determined the differences in the association between SNAP participation and eating behaviors by the presence or absence of food outlets adjusted for covariates.

Results

SNAP participation was associated with a higher frequency of consuming sugar-sweetened beverages (P<0.05) when respondents lived within ¼ to ½ mile of a small grocery store, supermarket, and limited service restaurant. SNAP participants who did not live close to a convenience store reported a lower frequency of sugar-sweetened beverage consumption (P=0.01), and those living more than ½ mile away from a supermarket reported a lower frequency of fruit consumption (P=0.03).

Conclusions

The findings from this study suggest that the community food environment may play a role in moderating the association between SNAP participation and eating behaviors. Although SNAP participation is associated with some unhealthy behaviors, this association may only hold true when respondents live in certain food environments.

Features of the built environment (BE) are related to a wide range of health factors, including leisure-time physical activity (PA) and active forms of transportation. For working adults, worksite neighborhood is likely an important BE to better understand the impact of various factors on PA patterns. Compared to home neighborhood walkability research, worksite walkability has received relatively less attention. The objective of this project was to identify if worksite walkability was significantly associated with PA behavior.

Aims: to evaluate 1) the PA variation explained by work walkability, 2) the moderating effects of person-level characteristics to the relationship between PA and work walkability, and 3) the differences in the rate of change in PA over time by worksite walkability.

Methods: self-report and accelerometer measured PA at baseline (aim 1, 2); longitudinal accelerometer PA during the initial 56 days of a behavioral intervention (aim 3). Adults were generally healthy and reported part- or full-time employment with a geocodeable address outside the home. Geographic Information Systems (GIS) measured walkability followed established techniques (i.e., residential, intersection, and transit densities, and land-use-mix).

Results: On average, worksite walkability did not show direct relationships with PA (aim 1); yet certain person-level characteristics moderated the relationships: sex, race, and not having young children in the household (aim 2). During 56 days of intervention, the PA rate of change over time showed no evidence of a moderating effect by worksite walkability.

Discussion: Worksite walkability was generally not shown to relate to the overall PA. However, specific subgroups (women, those without young children) appeared more responsive to their worksite neighborhood walkability. Prior literature shows certain demographics respond differently with various BE exposures, and this study adds a potentially novel moderator of interest regarding young children at home. Understanding who benefits from access to walkable BE may inform targeted interventions and policy to improve PA levels and foster health equity.

Through three investigations, this dissertation examined properties of the family and early care and education center (ECEC) environments related to preschool-aged children’s cardiovascular fitness (CVF) and gross locomotor skills (GLS). Investigation one used a systematic review and meta-analysis to synthesize the effectiveness of school-based interventions at improving CVF, in preschool-aged children. For investigations two and three product- and process-based measures of GLS were collected from children in ECECs (n=16), using the progressive aerobic cardiovascular endurance run (PACER; n=144) and the CHAMPS motor skill protocol (CMSP; n=91), respectively. Investigation two and three examined family factors and ECEC factors for associations with measures of GLS, respectively.

Investigation one revealed a moderate-to-large effect size for school-based interventions (n=10) increasing CVF (g=0.75; 95%CI [0.40-1.11]). Multi-level interventions (g=.79 [0.34-1.25]) were more effective than interventions focused on the individual (g=0.67 [0.12-1.22]). In investigations two and three children (78.3% Hispanic; mean ± SD age 53.2±4.5 months) completed a mean ± SD 3.7±2.3 PACER laps and 19.0±5.5 CSMP criteria. Individual and family factors associated with PACER laps included child sex (B=-0.96, p=0.03) and age (B=0.17, p<0.01), parents’ promotion of inactivity (B=0.66, p=0.08) and screen time (B=0.65, p=0.05), and parents’ concern for child’s safety during physical activity (B=-0.36, p=0.09). Child age (B=0.47, p<0.01) and parent employment (B=2.29, p=0.07) were associated with CMSP criteria. At the ECEC level, policy environment quality (B=-0.17; p=0.01) was significantly associated with number of PACER laps completed. Outdoor play environment quality (B=0.18; p=0.03), outdoor play equipment total (B=0.32; p<0.01) and screen time environment quality (B=0.60; p=0.02) were significantly associated with CMSP criteria. Researchers, ECEC teachers and policy makers should promote positive environmental changes to preschool-aged children’s family and ECEC environments, as these environments have the potential to improve CVF and GLS more than programs focused on the child alone.

Having accurate measurements of sedentary behaviors is important to understand relationships between sedentary behaviors and health outcomes and to evaluate changes in interventions and health promotion programs designed to reduce sedentary behaviors. This dissertation included three projects that examined measurement properties of wearable monitors used to measure sedentary behaviors. Project one examined the validity of three monitors: the ActiGraph GT3X+, activPAL™, and SenseWear 2. None of the monitors were equivalent with the criterion measure of oxygen uptake to estimate the energy cost of sedentary and light-intensity activities. The ActivPAL™ had the best accuracy as compared with the other monitors. In project two, the accuracy of ActiGraph GT3X+and GENEActiv cut-points used to assess sedentary behavior were compared with direct observation during free-living conditions. New vector magnitude cut-points also were developed to classify time spent in sedentary- and stationary behaviors during free-living conditions. The cut-points tested had modest overall accuracy to classify sedentary time as compared to direct observation. New ActiGraph 1-minute vector cut-points increased overall accuracy for classifying sedentary time. Project 3 examined the accuracy of the sedentary sphere by testing various arm elevation- and movement-count configurations using GENEActiv and ActiGraph GT3X+ data obtained during free-living conditions. None of the configurations were equivalent to the criterion measure of direct observation. The best configuration of the GENEActiv was: worn on the dominant wrist at 15 degrees below the horizontal plane with a cut-point <489 for each 15-second interval. The best configuration for the ActiGraph was: worn on the non-dominant wrist at 5° below the horizontal plane with a cut-point of <489 counts for each 15-second interval. Collectively, these findings indicate that the wearable monitors and methods examined in this study are limited in their ability to assess sedentary behaviors and light intensity physical activity. Additional research is needed to further understand the scope and limitations of wearable monitors and methods used to assess sedentary behaviors and light intensity physical activity.

Background: Stroke is a leading cause of long-term disability in the United States (US). Assisted Cycling Therapy (ACT) incorporates the use of an electric motor to enhance the rotations per minute (rpm). ACT of about 80 rpm, has been associated with improvements in motor, cognitive, and clinical function. The acute effects of ACT on motor and cognitive function of persons with stroke induced deficits have not been investigated.

Purpose: To compare the acute effects of ACT, voluntary cycling (VC), and no cycling (NC) on upper and lower extremity motor function and executive function in adults with chronic stroke (age: 60 ± 16 years; months since stroke: 96 ± 85).

Methods: Twenty-two participants (gender: female = 6, male = 16; types: ischemic = 12, hemorrhagic = 10; sides: left lesion = 15, right lesion = 7) completed one session of ACT, one session of VC and one session of NC on separate days using a 3 x 3 crossover design.

Results: ACT lead to greater improvements in lower and upper extremity function on the paretic and non-paretic side than VC or NC (all p < 0.05), except in the non-paretic lower extremity where ACT and VC produced similar improvement (both p < 0.05). ACT and VC, but not NC, were associated with improvements in inhibition (p < 0.05). A positive relationship between cadence and motor function (P < 0.05) was found. Ratings of perceived exertion shared an inverted-U shaped relationship with measures of processing speed (p < 0.05) and a negative linear relationship with measures of executive function (p < 0.05).

Conclusion: ACT appears to benefit paretic and non-paretic motor function globally whereas the benefits of VC are more task specific. Faster cycling cadence was associated with greater improvements in global motor function. ACT and VC seem to carry similar acute benefits in inhibition.

Background and purpose: Regular physical activity (PA) provides benefits for cognitive health and helps to improve or maintain quality of life among older adults. Objective PA measures have been increasingly used to overcome limitations of self-report measures. The purpose of this study was to investigate the association of objectively measured PA and sedentary time with cognitive function among older adults.

Methods: Participants were recruited from the parent REasons for Geographic and Racial Differences in Stroke (REGARDS) Study. ActicalTM accelerometers provided estimates of PA variables, including moderate-to-vigorous PA (MVPA), high light PA (HLPA), low light PA (LLPA) and sedentary time, for 4-7 consecutive days. Prevalence and incidence of cognitive impairment were defined by the Six-Item Screener. Letter fluency, animal fluency, word list learning and Montreal Cognitive Assessment (orientation and recall) were conducted to assess executive function and memory.

Results: Of the 7,339 participants who provided accelerometer wear data > 4 days (70.1 ± 8.6 yr, 54.2% women, 31.7% African American), 320 participants exhibited impaired cognition. In cross-sectional analysis, participants in the highest MVPA% quartile had 39% lower odds of cognitive impairment than those in the lowest quartile (OR: 0.61, 95% C.I.: 0.39-0.95) after full adjustment. Further analysis shows most quartiles of MVPA% and HLPA% were significantly associated with executive function and memory (P<0.01). During 2.7 ± 0.5 years of follow-up, 3,385 participants were included in the longitudinal analysis, with 157 incident cases of cognitive impairment. After adjustments, participants in the highest MVPA% quartile had 51% lower hazards of cognitive impairment (HR: 0.49, 95% C.I.: 0.28-0.86). Additionally, MVPA% was inversely associated with change in memory z-scores (P<0.01), while the highest quartile of HLPA% was inversely associated with change in executive function and memory z-scores (P<0.01).

Conclusion: Higher levels of objectively measured MVPA% were independently associated with lower prevalence and incidence of cognitive impairment, and better memory and executive function in older adults. Higher levels of HLPA% were also independently associated with better memory and executive function. The amount of MVPA associated with lower risk of cognitive impairment (259 min/week) is >70% higher than the minimal amount of MVPA recommended by PA guidelines.