Youth Lifestyle Intervention With Food and Exercise (MYLIFE)

Rationale: Childhood obesity is an increasingly major health care problem in Canada. Not only are approximately 30% of Canadian children overweight/obese, but they are developing significant sequelae including insulin resistance, hyperinsulinemia, hyperlipidemia, hypertension, and diabetes mellitus. Additionally obese children have lower bone mass, lower 25(OH)D concentrations and fracture more frequently. Canadian children on average do not meet the recommended intakes for vegetables and fruit and only half of those < 8 years old meet the recommended intakes for milk. Obese children are more likely to be inactive and spend more screen-time during their free time. There is promising childhood evidence that diets with 3 to 4 servings of milk support healthier body composition (lean mass and height) and improved insulin sensitivity in the short term and bone mass in the longer term. Family based interventions are effective in weight reduction in children. To date, a combined assessment of the benefits of improved intakes of milk plus active lifestyles in obese children on body composition, bone and blood biochemistry in a family intervention is lacking.

Objectives and Hypotheses:

1. To determine if a 1-year lifestyle intervention with planning sessions designed to improve diet and activity within the context of the family environment will reduce adiposity and elevate lean mass while supporting bone mass in obese children compared to a control group and if augmented intake of milk to 4 daily servings will result in superior changes. The primary outcome will be change in body mass index (BMI) Z-score along with waist circumference for assessment of adiposity; selected for ease of use in larger studies or clinics where body composition assessment is not feasible.

   Hypothesis: the lifestyle intervention will yield modest changes to adiposity and lean mass accompanied by no reductions in bone mass, but that the augmented milk intervention will yield superior reductions in adiposity and elevations in lean and bone mass and height growth. It is hypothesized that bone mass will be low and that maintenance of bone mass in the standard intervention will thereby be judged as inadequate.

2. To explain the hypothesized benefits of these interventions on lean, adipose and bone masses by measuring indicators of glucose metabolism, satiety and related gut hormones along with novel biomarkers of skeletal metabolism including osteocalcin, adiponectin and vitamin D.

   Hypothesis: high milk intake will associate with lower glucose, insulin, ghrelin and 1,25(OH)2D accompanied by higher 25(OH)D, osteocalcin, peptide YY and glucagon-like peptide 1.

3. Test if the intervention with higher milk servings is linked to changes in child eating behavior and satiety using the Child Eating Behavior Questionnaire to reflect eating in the child's normal environment.

Hypothesis: children randomized to the high milk intervention group will demonstrate improved scores on the satiety responsiveness component of the survey.

METHODS - Randomized Controlled Trial Ethics: This study was approved by the McGill University Institutional Review Board of the Faculty of Medicine in October 2010 and will also be conducted in compliance with the Tri-Council Policy Statement 2005 and in compliance with local regulation and laws governing research involving human subjects. Otherwise healthy obese children (6 to 12 years of age) will be recruited following informed consent. Upon completion, the control group will be offered the counseling (5 visits) intervention adjusted for age (i.e. counseling + basic anthropometric measurements only).

Population and Recruitment: Obese children (n=150) from West-Island Montreal and surrounding off island areas within 50 km of the Macdonald Campus of McGill University. Our approach to recruitment is to use mailings through Canada Post. This service is excellent and the result is that for a particular area (predominantly West Island Montreal and off island areas towards Ottawa) each household receives a brochure on the study inviting them to attend if they have a child who has a body mass index (BMI) in our range. A graph will be provided to guide the parents and they will be invited to call us for more information. Obesity will be defined on the basis of body mass index > 95th percentile for age according to the World Health Organization. In total 150 children 6 to 12 years of age will be recruited over a 6-month window. Those meeting entrance criteria will be randomized into 3 groups:

1. a control group with information only (counseling after 12 months for 6-8 year olds and after 6 months for 9-12 year olds);
2. a lifestyle intervention (planning/counseling to improve diet and activity)(6-8 year olds only);
3. the same lifestyle intervention augmented with a total of 4 servings of milk/milk products daily (6-12 year olds).

Study Protocol: Participants will be screened for entrance criteria at a visit 2 weeks prior to beginning the 1-year program. Upon confirmation of meeting inclusion criteria, families will be telephoned to confirm participation and then 6-8 year olds will be randomized into the 3 groups stratified for sex and the 9-12 year olds will be randomized into the 2 groups stratified by sex. They (parents & child) will be asked to complete a 3-day diary of food the week prior to the baseline visit and at the visit complete questionnaires (activity, eating behavior, demographics etc.). These will be used as baseline measures for all groups and for the lifestyle intervention groups to guide interventions regarding food choices and activity preferences. At the baseline visit, blood sampling, dual energy x-ray absorptiometry (DXA) and anthropometric measurements will be completed. All groups will receive simple education at the baseline visit regarding Canada's Food Guide and Canada's Activity Guide and given a 3-day diary to document their food. A registered dietitian will go through the content with them to explain how to use the guides and food-diary. Then each group will be seen at 3, 6, 9 and 12 months of study to obtain new diaries, and perform anthropometric measurements and blood biochemistry. Surveys (activity, satiety) will be taken at these visits. Body composition and bone mass will be measured at baseline, 6 and 12 months. The intervention groups will have lifestyle counseling visits at the end of months 1 through 5 to enable individualized family-child counseling (intensive phase) followed by every 3 months (establishing phase 9 months plus all receive debriefing at 12 months by a study coordinator). Intervention families will receive a monthly telephone call for any outstanding issue or to reinforce lifestyle change.

Details of Family-Child counseling at end of months 1 through 5 plus 9 mo (1.5 h visits): Intervention groups will have planning/counseling sessions for a total of 9 hours based on 5 x 1.5 h visits at the end of months 1 through 5. An additional visit at 9 mo (1.5 h) will be used to determine if new diet and activity intervention strategies are necessary over time as the child grows/matures and due to season. Counseling visits at end of months 2, 5 and 9 overlap with regular study visits and will be conducted after study data is collected to limit leading and bias (same day if need be to limit travel). All intervention planning visits will be with a registered dietitian. Both intervention groups will be instructed in detail how to use Canada's Food Guide and Activity Guide (which includes reducing screen time) and asked to set goals under the family-based behavioral intervention model of Epstein; while considering the environmental and developmental frameworks to arrive at suitable planning in the family/near environment plus suitable for the child's developmental age. The model of Epstein is grounded in the social learning theory in view of the choices, planning and reinforcement, but adapted for children/families resources and environment with reinforcement of positive behaviors. Children and families need to change together as a whole but also in support of the child being able to make decisions while away from home. This has been applied in an intervention to improve asthma control in children at and away from home.

Canada's food guide servings for Milk and Alternatives (these include for example 250 ml fluid milk, 250 ml soy beverage, 175 g yogurt, 175 kefir, 50 g cheese) is 2 per day for children 4 to 8 years of age and servings of vegetables and fruits is 5 per day. The augmented intervention group will be instructed to consume 4 servings of milk or milk products daily (these include for example 250 ml fluid milk, 175 g yogurt, 50 g cheese). The 4 servings of milk aligns with the recommended servings for 9 to 14 year old children; the age at the end of the study or soon thereafter. This intervention approach is both ethical and forward-looking. It would be unethical to counsel children and parents to not achieve the recommended 2 servings of milk and alternative products for an 8 year old. Upon completion of the study the investigators will survey families regarding sustainability of intakes at 4 servings a day - for children turning 9 years old this is the recommendation.

The intervention groups will also have counseling on other food groups to result in a healthy diet overall. Meal planning at each visit for both interventions will use Canada's Food Guide and include age appropriate serving sizes, approaches to combining foods to enhance satiety, how to incorporate snacks and fun foods, cooking methods, hidden energy, and how to specifically increase vegetables, fruit and milk intakes for the family. The examples of servings listed previously are only a few. Within each family food preferences and availability will be used to counsel towards achieving 2 or 4 servings of milk and milk products a day. Similar family-based dietary interventions have been successfully used in overweight and obese children 6 years of age and higher. The intervention groups will also actively plan to increase activity according to the Activity Guide which includes increasing activity to 90 minutes daily and decrease in non-active time by 90 minutes over 5 months (hence the visits at end of months 1 through 5). The new My Food Guide on-line at Health Canada offers a convenient tool for planning of both diet and activity that can be used over the course of the study in conjunction with the full Health Canada educational tool for planning the 5-month increase in activity and reduction in screen time. Planning with parents and children together within the context of their environment, developmental stage and food and activity preferences is anticipated to improve the program's success. A focus on fun yet feasible activities will assist both children and parents in adhering to the program. Expert researchers and health care professionals have designed both of these Health Canada tools. In fact these tools are used in the Montreal Children's Hospital obesity clinics. The activity guide has been successfully used in a 4 week family program to enhance activity.