2019 Hamilton Award: Proving that dietary sugar increases body weight

Rates of obesity have been soaring in countries worldwide and New Zealand is no exception, with New Zealand now rated as the third most obese nation after the United States and Mexico. Obesity is associated with a large number of health issues from diabetes to heart disease so preventing it is a priority of nutrition policy globally.

Previously it was widely believed that added or freely available sugar in processed food and drinks contributed to weight gain but convincing research evidence was lacking. Population studies often failed to demonstrate a clear link between high consumption of free sugars and obesity. Other research had focussed instead on the metabolic effects of sugar in the diet compared with other macronutrients such as starch or fat rather than focussing on the overall effect of sugar in the diet.

In 2013 Dr Te Morenga published a breakthrough meta-analysis study in the prestigious British Medical Journal that clearly demonstrated a link between free sugars in the diet and the risk of excessive weight gain. By performing a meta-analysis on randomised dietary intervention trials she demonstrated that high sugar intake results in weight gain as a result of promoting excess energy consumption rather through a metabolic effect.

This research was undertaken for the World Health Organisation (WHO), informing its recommendations to limit intake of free sugar in the diet, which gave Lisa an invaluable opportunity to be part of an international evidence review process early in her research career.

Since the release of the recommendations in 2015, many countries have followed the WHO's direction and have introduced new policies to reduce intake of free sugar, with some jurisdictions introducing 'sugar taxes' as an attempt to reduce sugar consumption.

Subsequently, Lisa has led development of methods to estimate free sugar content of New Zealand foods to allow us to better monitor how much sugar New Zealanders are eating.

Lisa also uses her expertise on dietary sugars and health within a number of Māori and Pasifika community-based research collaborations. This work includes examining the relationship between sugar and chronic disease with Ngāti Porou and co-leading a Healthier Lives National Science Challenge project to co-design an mHealth app – OL@-OR@ – to support healthy lifestyles amongst Māori and Pacific whānau.

On receiving this award, Lisa said: “It a great honour to be recognised by Te Apārangi for my research. There are many challenges in being an early career researcher in New Zealand, particularly the lack of long-term job security. This is especially true for Māori researchers who can get stuck in an ongoing cycle of short term research contracts. I am therefore indebted to the Riddet Centre of Research Excellence, who have provided ongoing support, enabling me to sustain my research for the past eight years, as well as my many wonderful colleagues throughout New Zealand.”

Dr Te Morenga is a Senior Lecturer in Māori Health and Nutrition at Victoria University of Wellington. In 2018 she was awarded a prestigious Rutherford Discovery Fellowship by Royal Society Te Apārangi and was on the reference group for the Society's report Sugar and Health. She is an associate investigator with the Riddet Institute Centre of Research Excellence and the Ngā Pae o te Māramatanga Centre of Research Excellence and has been appointed to the New Zealand Health Research Council’s Public Health Committee and the Food Standards Australia and New Zealand Consumer and Public Health Dialogue.

Hamilton Award

For encouraging scientific research in New Zealand by early career researchers.

Citation:

To Lisa Anne Te Morenga for her contribution to international evidence-based nutrition policy stemming from her research examining the impact of dietary sugars on body weight