student profile: Mrs Heidi Louise Morahan


Thesis work

Thesis title: Metabolic and behavioural effects of prenatal exposure to highly sweetened diets

Supervisors: Lisa BERO , Kieron ROONEY , Robert BOAKES

Thesis abstract:

This research aims to explore the role of maternal diets high in sugar or non-nutritive sweeteners in rodent models and subsequent metabolic and/or behavioural impacts on offspring. The understanding of 'developmental programming' has been greatly advanced by the use of animal models, where maternal under and over-nutrition have produced offspring with altered phenotypes through dysregulated gene expression. Yet, there is a paucity of maternal animal studies investigating high sugar or non-nutritive sweetener diets to elicit potential transmission of risk for non-communicable diseases.

With the rise in global sugar consumption and associated links to obesity and comorbidities, sweeping recommendations to limit the intake of added sugar has led to a cultutral shift towards increased non-nutritive sweetener (NNS) consumption in food and beverages. Yet paradoxically, NNS has been linked with obesity, impaired glucose response, poor appetite control and altered gut microbiota, although there is limited and conflicting evidence in both animal and human studies. Large prospective human cohort studies reveal NNS consumption during pregnancy has an association with increased childhood BMI and risk of obesity, however results are limited by the inability to show causation.

Therefore the general aims of this research are:

  • Evaluate the current body of evidence through systematic reviews in animal studies for maternal NNS consumption and maternal high sugar consumption to clarify outcome measures in offspring
  • Assess the quality of studies using internal and external validity tools to provide descriptive analysis on outcomes
  • Determine ecologically valid models of non-nutritive sweetened beverage consumption in rodents to enhance translational capacity
  • Investigate if in utero exposure to a sweet diet without excess energy intake elicits similar metabolic affects to a sweet diet with excess energy content.

Note: This profile is for a student at the University of Sydney. Views presented here are not necessarily those of the University.