Consumers’ accuracy in estimating energy content of common foods in New Zealand (EIT Food Energy Survey)

Obesity is a serious chronic disease that currently affects 31.3% of adult New Zealanders. Obesity is the result of taking in more food energy than needed, and given the risks that arise from obesity, it is important to understand and investigate the multiple factors that contribute to obesity, such as how do people know how much they have eaten. Thus, the purpose of this study is to investigate consumers’ ability to estimate the energy content of foods commonly consumed in New Zealand and how this estimation ability might be related to their age, gender or BMI. This quantitative study asked the participants to estimate the energy content of 15 foods via images in a SurveyMonkeyTM online questionnaire. Two hundred and fifty-four individuals responded to this survey. The study population had a high proportion of females (75%), was older (58.1 ± 15.2 years), and had lower BMIs (BMI 27.6 ± 6.9) than the New Zealand average population. The proportion of accurately estimated energy contents (with an accuracy threshold of ±20% of the actual value) was 25.3%. The average absolute energy content estimation error was 48.2% (±25.9%), with the prevailing estimation error being underestimates. BMI and age were statistically significant (P=0.003 and P=0.014 respectively) and had a gender-independent effect on the estimation error, while gender was not a main effect on estimation error (P=0.238). Across all participants 87% showed a strong preference for answering in kilocalorie rather than kilojoule. The principal conclusion of this investigation was that, regardless of demographic characteristics, the participants’ ability to estimate the energy content of common foods from images was limited. The finding of this study that increasing BMI levels corresponded with increasing estimation error rates was in disagreement with prior research in this field, which asserted that BMI is not related. Furthermore, the detected effect of age on estimation error was a novel finding. Future interventions, such as health promotions and food label design requirements, should consider raising New Zealanders’ ability to estimate food energy of common foods and guiding individuals towards the use of kilojoule over kilocalorie. The shown effect of BMI on the ability to estimate food energy contents might warrant further investigation, as might the surprisingly high preference rates for the kilocalorie.

Name thesis:degree_name

Master of Health Science

Level thesis:degree_level

Masters

Grantor

Eastern Institute of Technology

Year dc:date.issued

2014

Author dc:creator

• Haas, Robert

• New Zealand
• consumers
• food
• food energy content
• estimation
• obesity
• surveys

Statement dc:rights

• All rights reserved

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10652/6393

OAI identifier oai:identifier

oai:null:10652/6393