Dietary energy density in the Australian adult population from national nutrition surveys 1995 to 2012 / Amanda Lee Grech, Anna Rangan, Margaret Allman-Farinelli

Background: It is hypothesized that the observed proliferation of energy-dense, nutrient-poor foods globally is an important contributing factor to the development of the obesity epidemic. However, evidence that the population's dietary energy density has increased is sparse. The World Cancer Research Fund recommends that dietary energy density be <1.25 kcal/g to prevent weight gain. Objective: The aim of this research was to determine whether the dietary energy density of the Australian population has changed between 1995 and 2012. Design: A secondary analysis of two cross-sectional Australian national nutrition surveys from 1995 and 2011/2012 was conducted. Participants/setting: Participants of the surveys included adults aged 18 years and older (1995 n=10,986 and 2011/2012 n=9,435) completing 24-hour dietary recalls, including a second recall for a subset of the population (10.4% in 1995 and 64.6% in 2011/2012). Main outcome measures: Outcome measures included the change in dietary energy density (calculated as energy/weight of food [kcal/g] for food only) between surveys. Statistical analysis: The National Cancer Institute method for "estimating ratios of two dietary components that are consumed nearly every day" was used to determine the usual distribution and the percentage of participants reporting energy density <1.25 kcal/g. Results: The mean (standard deviation) dietary energy density was 1.59 (0.26) kcal/g and 1.64 (0.32) kcal/g (P<0.0001) in 1995 and 2011/2012, respectively, with 13% and 5% (P<0.0001) of the population meeting dietary energy-density recommendations. For those aged 70 years and older, the percentage with energy density <1.25 kcal/g decreased from 22% to 6% (P<0.0001) for men and from 33% to 11% (P<0.0001) for women in 1995 and 2011/2012, respectively. Among those aged 18 to 29 years, 1% of men in both surveys (P=0.8) and 4% of women in 1995 and 2% in 2011/2012 (P=0.01) reported energy density <1.25 kcal/g. Conclusions: Dietary energy density has increased between the two surveys and few people consumed low energy-dense diets in line with recommendations. The change was largely due to increased energy density of older adult's diets, while young adults had high dietary energy density at both time points. These data suggest efforts now focus on the evaluation of the role of modifying energy density of the diet to reduce the risk of weight gain in adults.

Nutrition.