Identifying Causal Effects of the Built Environment on Physical Activity, Diet and Obesity among Children

Principal Investigator:

Gilliland, Jason (University of Western Ontario)


Shrubsole, Dan (University of Western Ontario); Ryan, Loretta; Branscombe, Nancy; Kennedy, Jim (London Development Institute); St. John, Cynthia; Stanford, Jay; Beath, Lynn; Livingstone, Lynne; Pollet, Graham (Middlesex London Health Unit); Fair, Ross; McMahon, Sue; Charuk, Darlene; Wilk, Piotr; Speechly, Kathy; Prapavessis, Harry (University of Western Ontario); Hess, Paul (University of Toronto); Gobert, Colleen (Brescia University College); Fleming, John; Avison, William (University of Western Ontario)   

1. The Health Problem/Issue 

Obesity is a critical public health problem. One out of every three children in Canada is overweight or obese. Children who are overweight are more likely to become obese adults. Serious health problems have been associated with being overweight or obese, such as heart disease and hypertension. Predictors of obesity include the number of calories consumed and the number of calories burned through physical activity. Some researchers believe that the built environment in which we live, play, shop, work, and go to school, influences obesity levels by making it hard or easy to be physically active and eat healthy foods. More research is needed to better identify how the built environment influences obesity. 

2. The Objectives 

Our overall objective is to assess how the built environment impacts physical activity and eating behaviours. This study focuses on children in grade 6 and 7 in Southwestern Ontario. One of our specific objectives is to map all the environmental features that are believed to be barriers or enablers for physical activity and healthy diets (such as parks and fast food restaurants). We will map and analyze features for the entire study region. Another objective is to discover how these barriers and enablers are actually used by different groups of children, and if they have an effect on obesity levels. We will also develop a software program that can be used by planners, developers, and policy makers for studying existing and proposed developments. The software will be distributed for free. Our ultimate goal is to provide information to guide policymakers and planners in making health-promoting changes in the built environment. 

3. The Approach 

We use a combination of approaches in this study. We use a computer mapping program called a ‘geographic information system’ to study potential barriers and enablers for physical activity and healthy food consumption in our study area. We then use surveys, diaries, and portable monitoring equipment to gather information about the physical activities and eating habits of children. We will use a tiny device called an ‘accelerometer’ to measure children’s physical activity levels. To monitor where activities take place in the region, subjects will also wear a small GPS (‘global positioning system’) device. Subjects will use these devices for seven days. Children will be studied in grade 6 and again in grade 7so that we can gather information about their behaviours before and after they experience a possible change in school environments. This study design helps us figure out the influence of the environment. The project draws on the expertise of all team members. The team is represented by experts in geography, planning, sociology, statistics, and the health sciences. Policy-makers and community leaders are also included on the team to ensure the work will be useful to the community. We believe this study will provide a model for future studies. 

4. The Unique Factors 

The first innovation relates to context. We know of no other study that focuses on the full range of environments: urban, suburban, small town, and rural. Most previous studies deal only with very large cities. There is a general lack of Canadian studies, especially at the County level. The most innovative aspect of this project is the study design. We use ‘quasi-experiments’ to compare obesity indicators and related behaviours among study populations before and after a major environmental change. For students, we use innovative combination of tools (administered one year apart) to compare how behaviours change among a group of students who change school neighbourhood, versus a group who do not. We know of no other study which combines GIS, GPS, accelerometers, and diaries to examine obesity-related activities over time and space. These methods allow us to answer questions about where, when, what, and how much activity takes place. Furthermore, we are examining a population which has received little attention in previous studies. Most work in this field focuses on middle-aged adults.  

5. How the project is relevant to the objectives of the initiative 

Our research is directly relevant to all four objectives of this HSFC initiative:  
a. Our study of how changes to children’s everyday environments influences their physical activity, diet and obesity levels has the potential to provide the information needed for making policy and environmental changes that can tackle childhood obesity at the population level. 
b. Our project will build research capacity by: a) improving methodologies for studying the impact of the built environment and environmental interventions on population health; b) generating high quality information on obesity levels and related behaviours for a large region of Ontario; and c) engaging new researchers and trainees to study the problem of childhood obesity. 
c. Our project encourages collaboration among a diverse network of experts. Our team includes researchers from the fields of geography, planning, sociology, epidemiology, paediatrics, nutrition, and exercise science. Our collaborators include influential policymakers and professionals from planning departments, public health units, school boards, non-profit agencies, and the development industry. 
d. Our project plan maximizes opportunities for effective exchange of information between researchers and knowledge users. In addition to writing reports and making public presentations, we have formed a ‘local expert advisory panel’ which will help us to effectively translate findings into changes in policy and practice aimed at creating healthier environments.