Obesity: genetic or environmental?

Rachael Taylor is a Research Associate Professor based at the Edgar National Centre for Diabetes Research, University of Otago. Her research focuses on the environmental factors that contribute to obesity.

Rachael is one of the investigators of several large projects aimed at determining different ways of effectively preventing children from becoming overweight or helping them to reduce their weight in an appropriate way. Her work is primarily concerned with human development post-birth.

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Obesity

Obesity is simply defined as having too much body fat for your particular weight or height. An average figure from the relevant research estimates that obesity is about 40% genetic and 60% due to environmental factors.

Environmental factors and obesity

Obesity is simply defined as having too much body fat for your particular weight or height. It is usually measured by an internationally recognised system known as body mass index (BMI). BMI is calculated by comparing your height to your weight. It’s quite simple in adults, but in children, the measurement is commonly adjusted depending on age and sex.

There are many different factors that contribute to obesity. An average figure from research studies estimates that obesity is about 40% genetic and 60% due to environmental factors, but there is a lot of variation in the scientific literature.

Environmental factors refer to things like the types of food you eat, how much food you eat, amounts of sugary drinks consumed, fruit and vegetable consumption, physical activity level, television viewing, computer use, the type of job you have and the sports you play. The impact of these factors is different for everyone.

For some people, the most effective technique to prevent or reduce obesity might be to reduce food portion size. For others, it might be to cut out sugary drinks or increase physical activity. This makes it difficult to manage obesity on a population or country level, as some initiatives might help some and do nothing for others.

Obesity intervention projects

Obesity has some serious implications for our mental and physical health. These range from self-esteem issues through to high cholesterol, high blood pressure, diabetes and heart disease. Although some of these issues don’t directly affect children, being overweight as a child dramatically increases your risk of being overweight as an adult, so it’s critical to address obesity from a young age.

The goal of the research by Rachael and her colleagues is to reduce the burden of childhood obesity by developing programmes that reduce both the number of children who are overweight or become overweight, as well as help children who are currently overweight.

The obesity intervention research projects that Rachel is involved with are all based on the best evidence available. This includes information about what works and what doesn’t from past projects in New Zealand and around the world. However, research is also about developing and trialling new ideas, and this is an important element of Rachael’s work.

The projects are many and varied and target individuals at many different stages of development. For example, some focus on pregnant women and mothers with small babies, and others target those in early childhood settings or primary schools.

You can’t change your genes

A key message from Rachael’s research is that there is no one quick fix or easy answer to the problem of obesity. Genetics is part of the equation, and some people definitely find it more difficult to maintain a healthy weight than others. However, although you can’t change your genes, you can focus on the environmental factors and make lifestyle changes that have a positive impact on your weight and overall health.

Obesity intervention projects can provide valuable data on the most effective means to manage environmental factors.