student profile: Ms Amanda Grech


Thesis work

Thesis title: Generational changes in the energy-density and diet quality of Australian diets and the obesity epidemic

Supervisors: Anna RANGAN , Margaret ALLMAN-FARINELLI

Thesis abstract:

The etiology of the global obesity epidemic is multi-factorial and complex, but broadly weight gain is explained by energy imbalance. “Obesogenic” environments are thought to promote energy imbalance through increased dietary energy and sedentary behavior while decreasing physical activity of the population. While there are several commonly held hypotheses about the nutritional changes that have taken place that may be precipitating the obesity epidemic, the actual changes to the population’s diet are still poorly understood. One hypothesis main hypothesis is that the energy density (kJ/g) of the diet has increased over time – as the total volume of food consumed daily remains fairly constant, a diet of high energy density will increase the total consumption of energy and potentially lead to over consumption. Another potential contributing factor to the obesity epidemic is that the diet quality of the population has deteriorated, with reduced intake of nutrient-dense core foods and increased consumption of dicretionary foods high in added sugars, fats and sodium. The aim of this research is to test the hypothesis of energy-density and to assess diet quality, to determine if changes have occurred at a population level. As age-period-cohort analysis of the prevalence of obesity has revealed that although older age groups have the highest prevalence of obesity, younger generations are at greater risk of developing obesity, in addition to temporal dietary changes, age and cohort difference will be also be examined. This will allow for more specific recommendations to be formulated for population subgroups. Data from three Australian national nutrition surveys spanning the past thirty years will be used for this analysis.

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