Article

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.

Back of people walking carry bags down street.

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.

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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.

Factors that cause obesity

Your weight is influenced by many factors. Associate Professor Rachael Taylor, from the University of Otago, is interested in the role of environmental factors including food, sugary drinks and activity level.

Point of interest:
What do you think Rachael means when she talks about the optimist and pessimist view of the role of genetics in obesity

Rights: The University of Waikato

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.

Nature of Science

Different scientists can have different points of view that do not always agree with each other. The study of obesity is a good example of a research area where many scientists hold different opinions, for example, which environmental factors have the biggest impact or whether genes or environmental factors play a bigger role.

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.

Obesity intervention projects

Associate Professor Rachael Taylor, from the University of Otago, is interested in developing programmes that help reduce childhood obesity. In this video, she talks about the APPLE research project that increased physical activity levels in a number of schools. This increase in activity had a positive impact on the weight of children.

Rights: The University of Waikato

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.

Related content

Read this article to find out more about how scientists identify particular gene variations that might increase a person’s susceptibility to a particular disease.

Discover a new approach to obesity treatment – designing foods that influence the body’s control mechanisms on appetite and energy intake.

Explore the issue of sugar in our diets in Sugar on trial and the related article Academics consider case against sugar.

Activity idea

Use the Futures thinking tool to investigate obesity and the impact it has on the health system in the activity Futures thinking about obesity

In Obesity risk factors students participate in a simulation that demonstrates that both genetic make-up and environmental factors influence an individual’s likelihood of becoming obese.

Useful links

Visit the Edgar Diabetes And Obesity Research website to learn more about Rachael and her colleagues’ research.

Visit the Ministry of Health website to learn more about obesity in New Zealand.

Published: 08 June 2011