Preschoolers, using stickers, will create two letters each week regarding a food or activity presented in the center-based program that they liked or want to try at home. Letters will be sent by the PM privately to each caregiver via Facebook messenger on two weekdays. Caregivers will be asked to answer two Facebook multiple-choice questions related to the letters each week by Sunday midnight (e.g., what foods listed in the their child's letter did the participant provide? and what activities listed in the their child's letter did the participant's family try?). Caregiver responses to the questions will be summed to indicate caregiver responses to child requests. Each preschooler's letters will be kept in his/her intervention binder with other intervention materials to present to his/her caregiver at Meeting 3. Weekly preschooler activities, with pictures or videos, will be shared with caregivers via the Facebook private group every week.

Built on previous research, preschoolers will receive weekly, age-appropriate, participatory learning co-delivered by teachers and MSU student educators. Session duration will be 20 minutes because children's normal attention span is 3-5 minutes per year of age, and 20 min/session is recommended for preschoolers. The already developed "Eat & Walk My ABCs" curriculum will be implemented. The curriculum includes four components: healthy eating learning, taste-testing activities, movement skill training, and fun physical activity.

Preschoolers' screen time will be assessed by two questions from the National Health and Nutrition Examination Survey (NHANES)-Physical Activity and Physical Fitness Survey. The two questions ask caregivers about the number of hours per day their preschooler watches television or videos and uses a computer or plays games. The scale has good reliability with coefficients ranging from 0.63 to 0.84. The sum score of the two questions (min-max: 0-24 hours/day) will be used to describe preschoolers' screen time, with a higher score indicating more screen time. Caregivers will complete the survey.

Data collectors will measure each preschooler (bulky clothing, shoes, and things in pockets removed) in a private room. In accordance with NHANES measurement protocol, height without shoes will be measured to the nearest 0.1 cm. with a Shorr Board (Weigh and Measure, LLC, Olney, MD), and weight in kg. will be measured to the nearest 0.1 kg. using a Seca model 874 portable electronic scale (Seca Corp., Columbia, MD). Two measurements will be taken for height and weight. If the two differ by < 0.5 cm. and < 0.5 kg., they will be averaged to determine the final height and weight, respectively. If the two measurements differ by ≥ 0.5 cm. or by ≥ 0.5 kg, a third one will be taken. If the 3rd measurement is ≥ 0.5 cm or ≥ 0.5 kg. different from the previous two measurements, process will be repeated and another data collector will measure. BMI percentile and BMI z-score for age and sex will be determined via SAS program for CDC Growth Charts.

The ten-item Block Fruit-Vegetable-Fiber Screener will assess the caregivers' fruit/vegetable intake (servings/day). This survey provides estimates for intake of food groups including total fruit/vegetable servings, dietary fiber (mg), Vitamin C (mg), magnesium (mg), and potassium (mg). The scale is significantly correlated with the full Block survey (r = 0.71). The established scoring equation will be used to calculate the number of servings of fruit/vegetable each participant consumes per day.

Caregivers' screen time will also be assessed by two questions from the National Health and Nutrition Examination Survey (NHANES)-Physical Activity and Physical Fitness Survey. The sum of the two questions (min-max: 0-24 hours/day) will be used to describe preschoolers' screen time, with a higher score indicating more screen time.

BMI will be calculated based on weight (kg)/height (m2) and used to determine caregivers' weight status. Data collection procedures for caregivers will be similar to those employed for preschoolers.

The 25-item Parental Knowledge Scale will be used to assess parental knowledge on preschoolers' dietary intake and physical activity. The 2-point Likert scale has been used with low-income parents. It has two subscales: nutrition knowledge (score range 0-10), and physical activity knowledge (score range 0-15), with a higher sum score indicating greater knowledge on healthy eating or physical activity.

Parent feeding practice skill will be assessed by the 33-item Child Feeding Questionnaire. The Child Feeding Questionnaire was developed to evaluate parental beliefs, attitudes, and practices regarding child feeding, with a focus on obesity proneness in children aged 2-11 years old. The 5-point Likert questionnaire, with good reliability and validity, includes seven factors: perceived responsibility, perceived caregiver weight, perceived child weight, concerns about child weight, pressure to eat, restriction, and monitoring. The mean score of the items for each factor, with a range from 1 to 5, will be calculated, with a higher mean score indicating greater perceived responsibility, perceived caregiver weight, perceived child weight, concerns about child weight, pressure to eat, restriction, and monitoring, respectively.

The 20-item Parental Self-Efficacy Scale, measuring caregivers' confidence to support their preschoolers' healthy eating and physical activity, will assess caregiver self-efficacy. The 10-point Likert scale has shown good reliability with Cronbach's alphas ranging from 0.72 to 0.94. It has two subscales: nutrition self-efficacy (12 items) and physical activity self-efficacy (8 items). The mean score, with a range from 0 to 10, will be calculated for each subscale, with a higher mean score indicating greater self-efficacy.

The 12-item Parental Support Scale for Eating Habits and Physical Activity will measure support for the child. The 6-point Likert scale has very good reliability with Cronbach's alphas ranging from 0.83 to 0.87. It has two subscales: nutrition support (7 items) and physical activity support (5 items). The mean score, with a range from 1 to 6, will be calculated for each subscale, with a higher mean score indicating greater parental support.

The 32-item Parenting Style and Dimensions Questionnaire will measure parenting practices. The 5-point Likert questionnaire is assessing three parenting styles: authoritative, authoritarian, and permissive. The questionnaire has good reliability with Cronbach's alphas ranging from 0.64 to 0.91. The mean score of items for each parenting style, with a range from 1 to 5, will be calculated, with a higher mean score indicating greater authoritative, authoritarian, or permissive parenting style, respectively.

The 20-item Family Nutrition and Physical Activity (FNPA) screening tool will assess the home environment. This 4-point Likert screening tool is used to assess home obesogenic environments and practices, including family meals, family eating practices, food choices, beverage choices, restriction/reward, screen time, healthy environment, family activity, child activity, and family schedule/sleep routine. It has two subscales: eating environment (10 items) and physical activity environment (10 items). The sum score of the 10 items, with a range from 20 to 40, will be calculated for each subscale, with a higher sum score indicating a healthier home environment.

Control group will receive usual Head Start activities during intervention period. After post-intervention data collection, each control caregiver will receive all intervention supplies and a mini program including a face-to-face or virtual caregiver meeting and 1-week preschooler program. The caregiver meeting will cover contents on alternative cooking ingredients, food labels, and portion sizes.

Total of all reporting groups

Data from caregivers and preschoolers were analyzed separately. Caregivers could select more than one choice and one caregivers selected both "female" and "male."

Data from caregivers and preschoolers were analyzed separately. Participants could select more than one choice making the Rows not mutually exclusive.

Control group will receive usual Head Start activities during intervention period. After post-intervention data collection, each control caregiver will receive all intervention supplies and a mini program including a face-to-face or virtual caregiver meeting and 1-week preschooler program. The caregiver meeting will cover contents on alternative cooking ingredients, food labels, and portion sizes.

Preschoolers' fruit/vegetable intake (servings/day) at home will be assessed by three non-consecutive 24-hour dietary recalls (one weekend day; two weekdays; randomly selected) with their caregivers over 2-3 weeks. The Project Manager will be trained at the University of Minnesota Nutrition Coordinating Center for two days and certified. The Project Manager will train interviewers to collect data individually from each caregiver via telephone. To aid in assessment of portion sizes, two-dimensional food models and measuring guides will be provided to caregivers at Head Start centers. Preschoolers' dietary intake at the Head Start center will be assessed by the dietary observation system on snacks and lunch on two selected weekdays (similar to the two weekdays selected for the 24-hour recall). The observed diet data will be entered into the Minnesota Nutrition Data System for Research for analysis.

Preschoolers' screen time will be assessed by two questions from the National Health and Nutrition Examination Survey (NHANES)-Physical Activity and Physical Fitness Survey. The two questions ask caregivers about the number of hours per day their preschooler watches television or videos and uses a computer or plays games. The scale has good reliability with coefficients ranging from 0.63 to 0.84. The sum score of the two questions (min-max: 0-24 hours/day) will be used to describe preschoolers' screen time, with a higher score indicating more screen time. Caregivers will complete the survey.

Data collectors will measure each preschooler (bulky clothing, shoes, and things in pockets removed) in a private room. In accordance with NHANES measurement protocol, height without shoes will be measured to the nearest 0.1 cm. with a Shorr Board (Weigh and Measure, LLC, Olney, MD), and weight in kg. will be measured to the nearest 0.1 kg. using a Seca model 874 portable electronic scale (Seca Corp., Columbia, MD). Two measurements will be taken for height and weight. If the two differ by < 0.5 cm. and < 0.5 kg., they will be averaged to determine the final height and weight, respectively. If the two measurements differ by ≥ 0.5 cm. or by ≥ 0.5 kg, a third one will be taken. If the 3rd measurement is ≥ 0.5 cm or ≥ 0.5 kg. different from the previous two measurements, process will be repeated and another data collector will measure. BMI percentile and BMI z-score for age and sex will be determined via SAS program for CDC Growth Charts.

The ActiGraph GT3X-plus accelerometer (www.theactigraph.com) will record acceleration counts from which minutes of MVPA per day will be estimated (analysis software available). Data collection procedure for caregivers will be similar to those employed for preschoolers, but different count thresholds will be used: moderate (2690-6166 counts/60 seconds) and vigorous PA (≥ 6167 counts/60 seconds). Sixty-second increments with counts ≥ 2690 will be summed to determine minutes of MVPA.

The ten-item Block Fruit-Vegetable-Fiber Screener will assess the caregivers' fruit/vegetable intake (servings/day). This survey provides estimates for intake of food groups including total fruit/vegetable servings, dietary fiber (mg), Vitamin C (mg), magnesium (mg), and potassium (mg). The scale is significantly correlated with the full Block survey (r = 0.71). The established scoring equation will be used to calculate the number of servings of fruit/vegetable each participant consumes per day.

Caregivers' screen time will also be assessed by two questions from the National Health and Nutrition Examination Survey (NHANES)-Physical Activity and Physical Fitness Survey. The sum of the two questions (min-max: 0-24 hours/day) will be used to describe preschoolers' screen time, with a higher score indicating more screen time.

BMI will be calculated based on weight (kg)/height (m2) and used to determine caregivers' weight status. Data collection procedures for caregivers will be similar to those employed for preschoolers.

The 25-item Parental Knowledge Scale will be used to assess parental knowledge on preschoolers' dietary intake and physical activity. The 2-point Likert scale has been used with low-income parents. It has two subscales: nutrition knowledge (score range 0-10), and physical activity knowledge (score range 0-15), with a higher sum score indicating greater knowledge on healthy eating or physical activity.

Parent feeding practice skill will be assessed by the 33-item Child Feeding Questionnaire. The Child Feeding Questionnaire was developed to evaluate parental beliefs, attitudes, and practices regarding child feeding, with a focus on obesity proneness in children aged 2-11 years old. The 5-point Likert questionnaire, with good reliability and validity, includes seven factors: perceived responsibility, perceived caregiver weight, perceived child weight, concerns about child weight, pressure to eat, restriction, and monitoring. The mean score of the items for each factor, with a range from 1 to 5, will be calculated, with a higher mean score indicating greater perceived responsibility, perceived caregiver weight, perceived child weight, concerns about child weight, pressure to eat, restriction, and monitoring, respectively.

The 20-item Parental Self-Efficacy Scale, measuring caregivers' confidence to support their preschoolers' healthy eating and physical activity, will assess caregiver self-efficacy. The 10-point Likert scale has shown good reliability with Cronbach's alphas ranging from 0.72 to 0.94. It has two subscales: nutrition self-efficacy (12 items) and physical activity self-efficacy (8 items). The mean score, with a range from 0 to 10, will be calculated for each subscale, with a higher mean score indicating greater self-efficacy.

The 12-item Parental Support Scale for Eating Habits and Physical Activity will measure support for the child. The 6-point Likert scale has very good reliability with Cronbach's alphas ranging from 0.83 to 0.87. It has two subscales: nutrition support (7 items) and physical activity support (5 items). The mean score, with a range from 1 to 6, will be calculated for each subscale, with a higher mean score indicating greater parental support.

The 32-item Parenting Style and Dimensions Questionnaire will measure parenting practices. The 5-point Likert questionnaire is assessing three parenting styles: authoritative, authoritarian, and permissive. The questionnaire has good reliability with Cronbach's alphas ranging from 0.64 to 0.91. The mean score of items for each parenting style, with a range from 1 to 5, will be calculated, with a higher mean score indicating greater authoritative, authoritarian, or permissive parenting style, respectively.

The 20-item Family Nutrition and Physical Activity (FNPA) screening tool will assess the home environment. This 4-point Likert screening tool is used to assess home obesogenic environments and practices, including family meals, family eating practices, food choices, beverage choices, restriction/reward, screen time, healthy environment, family activity, child activity, and family schedule/sleep routine. It has two subscales: eating environment (10 items) and physical activity environment (10 items). The sum score of the 10 items, with a range from 20 to 40, will be calculated for each subscale, with a higher sum score indicating a healthier home environment.

Control group will receive usual Head Start activities during intervention period. After post-intervention data collection, each control caregiver will receive all intervention supplies and a mini program including a face-to-face or virtual caregiver meeting and 1-week preschooler program. The caregiver meeting will cover contents on alternative cooking ingredients, food labels, and portion sizes.

The 16-week intervention includes three components:

1. Caregiver Component. Facebook-based program including four new habit-formation tasks/week, and 3 face-to-face or virtual caregiver meetings: MSU research staff will lead the meetings at Head Start centers (weeks 1, 8, & 16) to connect caregivers to each other, offer health information, and discuss behavioral change strategies.
2. Caregiver-Preschooler Learning. Preschoolers, using stickers, will create two letters each week regarding a food or activity presented in the center-based program that they liked or want to try at home. Letters will be sent privately to each caregiver , and caregivers will be asked to respond to the letters.
3. Center-based Preschooler Component. Built on previous research, preschoolers will receive weekly, age-appropriate, participatory learning co-delivered by teachers and MSU student educators.

Control group will receive usual Head Start activities during intervention period. After post-intervention data collection, each control caregiver will receive all intervention supplies and a mini program including a face-to-face or virtual caregiver meeting and 1-week preschooler program. The caregiver meeting will cover contents on alternative cooking ingredients, food labels, and portion sizes.