SMART 2.0: Social Mobile Approaches to Reducing weighT in Young Adults

Objectively measured weight in kilograms.

Weight and height will be combined to report BMI in kg/m^2.

Percent change in weight from baseline.

Percentage of participants who lost at least 3% of their weight from baseline.

Percentage of participants who lost at least 5% of their weight from baseline.

Objectively measured in centimeters.

Waist and hip circumference will be combined to report waist-to-hip ratio in cm/cm.

Total body and regional (arms, legs, trunk, and abdomen) body composition (fat mass, including an estimate of visceral adipose tissue, and lean mass) measured with Dual-energy X-ray Absorptiometry (DXA).

Bone mineral density of anterior-posterior spine (L1 - L4), hip, forearm, and total body measured with Dual-energy X-ray Absorptiometry (DXA).

Systolic blood pressure in mmHg.

Diastolic blood pressure in mmHg.

Three-minute step test.

Sit and reach test.

Grip strength of the right and left hands in kilograms with a dynamometer.

Measured using Fitbit.

Measured using a waist-worn tri-axial accelerometer.

Assessed through self-report using the Global Physical Activity Questionnaire. The questionnaire is comprised of 16 questions related to physical activity in three settings that include activity at work, travel to and from places, and recreational activities, in addition to sedentary behavior. Metabolic Equivalent (MET) values are assigned to time variables according to intensity of activity, moderate or vigorous, reported in each of the settings. MET values are then used to calculate total physical activity.

Measured using Fitbit.

Assessed through self-report using an 8 item self-report questionnaire. Participants respond to questions related to sleep duration and how often they have difficulty falling asleep and staying awake, do not get enough rest.

Measured using Fitbit.

Measured by research assistant.

Measured using Fitbit.

Measured using a waist-worn tri-axial accelerometer.

Assessed through self-report using 5 items from the Canadian Fitness Survey and 10 items from the Past-day Adults' Sedentary Time Questionnaire. Participants respond to items from the Canadian Fitness Survey related to how much time participants spend doing sedentary activities on a 5-point response scale ranging from "Almost all of the time" to "Almost none of the time". Participants respond to items from the Past-day Adults' Sedentary Time Questionnaire related to how much time spent sitting while doing activities including working, transportation, etc. using 2 digit entry for hours and minutes. For all items, less time reported doing sedentary activities or sitting represents less sedentary behavior.

The Diet History Questionnaire III contains 135 food and beverage items and 26 dietary supplement items to assess diet consumption for past month. The questionnaire includes additional embedded questions for some items to assess frequency and portion size.

Assessed through self-report using a 3-item questionnaire. Participants respond to items related to which behaviors they have engaged in in the past 30 days to lose weight, how often they weigh themselves using a 6 point response scale ranging from "Never" to "More than once a day", and whether they have access to a scale at home.

Strategies for Weight Management Questionnaire consists of 35 items that assess how often participants use of behavioral strategies for reducing energy intake and increasing energy expenditure on a 5-point response scale ranging from "Never or hardly ever" to "Always or almost always". Values which indicate a higher frequency of strategies, "Much of the time" and "Always or almost always", show improved weight management.

Assessment of Eating Behaviors survey consists of 8 items that assess sugar sweetened beverage consumption and frequency of eating away from home on a 9-point response scale ranging from "Never or rarely" to "3 or more times per day".

Assessed through self-report using a 7-item questionnaire. Participants respond to items related to how often they eat meals and snacks in a typical week using a 5-point response scale ranging from "0 times" to "7 times".

Healthy Eating: Change Strategies survey consists of 15-items that assess how often participants engage in strategies that help them change their dietary habits in the past month using a 5-point response scale ranging from "Never" to "Many times".

Physical Activity: Change Strategies survey consists of 15-items that assess how often participants engage in strategies that help them change their physical activity in the past month using a 5-point response scale ranging from "Never" to "Many times".

Physical Activity Neighborhood Environment survey consists of 17-items that assess the environmental factors for walking and bicycling in various neighborhoods. Higher values from the scale indicate greater environmental support for physical activity.

Social Support for Diet survey consists of 10-items that assess perceived social support specific to health-related eating behaviors from family and friends, respectively. Each item uses a 8-point response scale that includes "does not apply" and ranges from "none" to "very often".

Assessed using the Physical Activity and Social Support Scale which consists of 20-items scale based in five forms of social support - companionship, emotional, instrumental, informational, and validation for physical activity. Participants respond to items on a 7-point Likert scale ranging from "never" to "always", or "not applicable".

Assessed using the Center for Epidemiologic Studies depression scale which consists of 10-items. Participants respond to items related to how they feel and behave on a 5-point response scale ranging from "Rarely or none of the time" to "All of the time". A score equal to or above 10 is considered depressed.

Assessed using the short-form of the state scale of the Spielberger State Trait Anxiety Inventory which consists of 6 items. Participants respond to items related to how they feel on a 4-point response scale ranging from "Not at all" to "Very much".

Assessed using the Rosenberg Self-esteem Scale which consists of 10-items. Participants respond to items related to items related to global self-worth on a 4-point Likert scale ranging from "strongly agree" to "strongly disagree". Higher scores indicate higher self-esteem.

Assessed using the Quality of Well-being survey, self-administered version which consists of 71 items. Participants respond to items related to health status and overall well-being over the previous 3 days. Scores are translated to quality-adjusted life years.

Assessed using the Eating Disorder Inventory, Body Dissatisfaction sub scale which consists of 9-items. Participants respond to items related to their body image on a 6-point response scale ranging from "Never" to "Always".