Outcome
Type |
Measure |
Description |
Time frame |
Safety issue |
Primary |
Objective 1 Primary Outcome: Change in minutes of sedentary behavior |
Physical activity and sedentary behavior will be measured by a triaxial accelerometer (Actigraph GT3X+, Actigraph of Ft. Walton Beach, FL). The participant will be instructed to wear the accelerometer on an elasticized belt, on the left mid-axillary line. The Actigraph is one of the most common accelerometers used for scientific purposes. Participants will be encouraged to wear the accelerometer 24-hours per day for at least 7-days (plus an initial familiarization day and the morning of the final day), including 2 weekend days. Participants will also complete a Lifestyle survey to collect information including diet and physical activity habits. |
Year 0 and Year 2 |
|
Primary |
Objective 2 Primary Outcome: Relationship between total fat accumulation and change in sedentary behavior. |
Body composition will be determined by DXA and MRI. With DXA, total body fat and trunk fat will be measured by whole-body DXA using a GE iDXA scanner (GE Medical Systems, Milwaukee, WI) to quantify total and regional body fat (including trunk fat). MRI - Visceral fat, i.e. visceral adipose tissue, will be measured by water-fat shifting MRI using the General Electric Discovery 750w 3.0 Tesla (GE Medical Systems, Milwaukee, WI). IDEAL-IQ imaging technique will be used to generate water-only, fat-only, in-phase, and out-of-phase echoes in a single acquisition with a 20-second breath-hold. Sedentary behavior will be measured by a a triaxial accelerometer as described in outcome 1. Participants will also complete a Lifestyle survey to collect information including physical activity habits. |
Year 0 and Year 2 |
|
Primary |
Objective 3 Primary Outcome: Relationship between BMIz and the environmental (or socio-emotional) factors. |
BMIz will be calculated based on the participant's age, height, and weight using the CDC 2000 growth charts. To identify where physical activity occurs, children will wear the QStarz BT Q1000XT data logger for 7 days concurrent with the ActiGraph GT3X+. In regards to the environmental factors, parents of participants will complete the Neighborhood Impact on Kids (NIK) survey, and participants will complete a neighborhood perceptions survey. In regards to socio-emotional factors, participants will complete the Body Image Assessment for Preadolescents, the Mood and Feelings Questionnaire, the Health-Related Quality of Life, the Personal Experiences Checklist related to stress, and the Food Craving Inventory. Further, participants will record negative and positive affect during a 7-day period by responding to prompts on a mobile phone-based app, using ecological momentary assessment. |
Year 0 and Year 2 |
|
Secondary |
Objective 1 Secondary Analysis: Change in daily moderate to vigorous physical activity (MVPA) minutes between years. |
MVPA measured by a triaxial accelerometer (Actigraph GT3X+, Actigraph of Ft. Walton Beach, FL) as described in outcome 1. Participants will also complete a Lifestyle survey to collect information including physical activity habits. |
Year 0 and Year 2 |
|
Secondary |
Objective 1 Secondary Analysis: Change in days/week of physical activity between years. |
MVPA measured by a triaxial accelerometer (Actigraph GT3X+, Actigraph of Ft. Walton Beach, FL) as described in outcome 1. Participants will also complete a Lifestyle survey to collect information including physical activity habits. |
Year 0 and Year 2 |
|
Secondary |
Objective 2 Secondary Analysis: Relationship between fat mass accumulation and change in physical activity. |
Body composition will be determined by DXA and MRI. With DXA, total body fat and trunk fat will be measured by whole-body DXA using a GE iDXA scanner (GE Medical Systems, Milwaukee, WI) to quantify total and regional body fat (including trunk fat). MRI - Visceral fat, i.e. visceral adipose tissue, will be measured by water-fat shifting MRI using the General Electric Discovery 750w 3.0 Tesla (GE Medical Systems, Milwaukee, WI). IDEAL-IQ imaging technique will be used to generate water-only, fat-only, in-phase, and out-of-phase echoes in a single acquisition with a 20-second breath-hold. Physical Activity will be measured by a triaxial accelerometer as described in outcome 1. Participants will also complete a Lifestyle survey to collect information including physical activity habits. |
Year 0 and Year 2 |
|