The FLAME Study (Family, Lifestyle, Activity, Movement, and Eating)

Indentifying Risk Factors in Obesity

Professor Barry Taylor

Department of Women’s and Children’s Health

University of Otago

Background to Research

The annual cost of obesity to the New Zealand healthcare system was estimated at $135 million in 1996, but conservatively excludes the downstream cost of chronic disease resulting from obesity.  Diabetes and coronary heart disease alone could increase the financial burden by as much as $747 million/year.

New Zealand has been inadequately prepared for the worldwide epidemic in obesity.  Worldwide, 22 million children under the age of five are estimated to be overweight.  Obesity is increasing in prevalence, becoming established earlier in life and overweight children are becoming heavier.  In New Zealand in 2002, a disturbing 27% of five to six- year-olds were identified as overweight or obese.  Using growth charts recently published by the World Health Organisation, we found that in 2004, an alarming 50% of our sample of Dunedin three-year-olds were overweight or obese.

Without prevention or early intervention, overweight children carry with them into adulthood, adverse risk for cardiovascular disease, hypertension, stroke, type 2 diabetes, certain forms of cancer, and psychosocial problems.  There is also now good evidence that an overweight child who becomes an overweight adult, has a much greater risk of cardiovascular problems than someone who becomes overweight during adulthood.

What are your research objectives?

We are following 240 families with three-year-old children, over a four-year period until their children turn seven, to determine which family lifestyle factors, related to physical activity, sedentary behaviour and eating habits predict childhood obesity.  By identifying associations between the development of obesity and behaviour in the preceding pre-school years, the FLAME study will have implications for a time in life when intervention may still have preventative potential.

How will you conduct your research?

Since 2004, our sample of 240 three-year-olds have been receiving six-monthly measurements of height, weight, waist circumference, and body composition (fat and lean tissue mass) using a simple bioelectrical test.  From these measures we derive estimates of the children’s body composition, which are validated at age five by an x-ray scan (DXA scan).

Children’s dietary intakes and families’ eating habits are annually assessed by questionnaire and by three-day food diaries which record each child’s intake of specific foods, food groups, and beverages relevant to obesity.  Parents’ control and concern regarding their child’s diet, the structure of family meal times, and the frequencies of missed meals, TV meals, and takeaways are also assessed by questionnaire.

A unique feature of our study is the use of a recent technological innovation to provide objective measures of physical activity.  The accelerometer is a small unobtrusive device, which measures movement in three dimensions.  Parents and children in our study wear a waist-mounted accelerometer for seven consecutive days and repeat measures are obtained from children once a year.

Are there others in your field in NZ or globally conducting similar research?

Although a considerable amount of research is being conducted to address the worldwide problem of obesity, few longitudinal studies have investigated obesity- promoting family lifestyle factors in the pre-school age group.

What is innovative about the approach you are taking?

The FLAME study offers a unique contribution to existing research for the following reasons:

Following children over a four year period, rather than taking a cross-sectional snapshot at a particular age, identifies specific lifestyles that are more likely to be the causal determinants of children’s obesity.

Obtaining information from both parents and child provides a comprehensive assessment of obesity-promoting lifestyles within the whole family environment.

Investigating the pre-school and early childhood years focuses on an important, but previously under-researched period in the development of childhood obesity.  Since the weight status of a child, as young as seven years, is a reliable predictor of their weight status as an adult, an effective prevention strategy needs to be founded on age-appropriate research.

Using the accelerometer to provide an unambiguous, objective measure of physical activity will help clarify the subjective, often proxy-reports of physical activity that previous studies have derived from questionnaires.

If you achieve your objectives what will that mean to those suffering from the disease or to the knowledge advancement of this disease?

The development of an obesity-prevention strategy will clearly benefit from knowing the obesity-promoting family lifestyles of contemporary pre-schoolers.  From the outcome of the FLAME Study, we will be able to identify pre-schoolers who are at risk of becoming overweight, and we will have important implications for interventions designed to alter their growth trajectory.

Is there national or international collaboration on your research project?

A precise measure of children’s percentage body fat has been obtained by x-ray scan (DXA-scan) in conjunction with Professor Ailsa Goulding (University of Otago, Dunedin).  Dr Leigh Ward (University of Queensland) has extensive experience with the bioelectrical test we use to measure body composition and will assist in validating this procedure with our three to seven year-old children.