Dietary assessment and physical activity measurements toolkit

Dietary assessment - Future developments


Technology offers many opportunities for the development of novel methods to collect dietary data and enhancing the quality of this data.  The fundamental methods of dietary assessment, i.e. a retrospective recall / questionnaire, or a prospective record are likely to underpin dietary assessment methodology in the future.  The advent of technology offers exciting possibilities on how dietary data may be collected.  Web-based or computer assisted questionnaires, recalls or diaries are becoming increasingly common.  The use of technology to collect dietary intake data is especially engaging to children, adolescents and younger adults who are familiar with it in their daily lives. However, the use of technology, particularly web-based questionnaires, in an older population with less technical experience may not be as appealing.

There is potential to collect dietary information from a representative sample of school children by using the computing facilities in school. For adults it is important to bear in mind that not all individuals will have access to computers or the internet. In order to obtain a representative sample it may be necessary to provide them with access for the duration of the data collection period.

Web-based assessments
Web-based questionnaires offer many advantages. They are quick, easy and cheap to administer. They include internal checks to flag missing, incomplete or implausible answers.  They allow summarisation of answers and immediate feedback to the respondent.  A number of web-based questionnaires have been assessed and found to be feasible and acceptable to respondents (Boeckner et al, 2005; Balter et al, 2005; Lu et al, 2006;); comparisons of a web–based FFQ and a traditional FFQ to a dairy method yielded similar correlations (Mathyss et al, 2007). 

Moore et al (2007) developed a new web-based piece of software Synchronised Nutrition and Activity Program (SNAPTM) to assess dietary intake and physical activity simultaneously in children. Dietary intake was assessed using ‘counts’ for 21 foods and then compared to dietary data obtained by a 24 hour multiple pass dietary recall. The authors concluded that it provides a quick, accurate, low-burden and cost-effective estimation of dietary intake. Results if a second validation study are due for publication in 2009. Following on from this work, the team at Durham University, Uk have developed a version of the software for use with adult populations - Synchronised Nutrition and Activity Program in Adults (SNAPATM).  

Building on experience of the United States Department of Agriculture (USDA) Automated Multiple Pass Method, Subar et al (2007) have developed a computer-based, self-administered 24-hour dietary recall for use in adults. This development work is particularly interesting because it reports on the formative cognitive and usability testing of two versions of recalling food intake; the ‘quick list’ for remembering foods consumed the previous day and the ‘unstructured’ and ‘meal-based’ approach. The latter was strongly preferred by respondents; this has implications for interviewers undertaking dietary recalls. 

Portion size estimation
There is currently a project at Newcastle University, UK developing a computer program to assist in portion size estimation in children using photographs based on child portions; the tool in use, is known as the Interactive Portion Size Assessment System (IPSAS (Foster et al).  Pilot work showed encouraging results. Three methods, the IPSAS, food photographs and food models were all compared against direct observations of children's intakes. Children were served specific weights of foods and the leftovers were weighed. Estimations using the three methods were then compared with the known quantities. The accuracy and precision of estimates made using the photographs and IPSAS were comparable.

Use of Personal Device Assistants and mobile phones
The future of dietary assessment may lie with the technology available in Personal Device Assistants (PDAs) or mobile phones for examples.  A study in children and adolescents has shown that capturing food intake by PDAs or disposable cameras was preferred to pen and paper methods (Boushey et al). 

Dr Carol Boushey and colleagues from many disciplines at Purdue University in the US are undertaking pioneering work in dietary assessment. The team are developing a computing device which will include digital images, a nutrient database, and image analysis for identification and quantification of food consumption. Mobile computing devices provide a unique vehicle for collecting dietary information that reduces the burden on record keepers.  Using image calibration, acquisition, and image segmentation, methods are being developed to automatically estimate the volume of the foods consumed from images captured with a mobile device (Zhu et al., 2008). The technology is based on that used to estimate the height of mountains in cartography. 

In Japan, the Wellnavi-instrument (Matsushita Electric Works, Ltd, Osaka, Japan) has been developed, in which a camera captures a photo of a meal, the names of the ingredients can be added for clarification, and then a mobile phone card transmits the digital photo to a dietitian who then returns the calculated nutrient intake.  Validation studies on the instrument have been undertaken. In the first study, 20 college students kept a one day weighed diet record whilst sending images to dietitians via the mobile phone card. The mean correlation coefficient for nutrient intakes between the median nutrient intakes calculated by both methods was 0.77 and ranged from 0.46 to 0.93.  Reliability was also assessed and showed good agreement between two Wellnavi instruments (Wang et al 2002).  A second study carried out in 28 college students also indicated good correlations with a one day weighed record and a 24-hour recall obtained the next day; mean correlation coefficient 0.66 (Wang et al 2006).  In this study, over half the individuals found the Wellnavi instrument the least burdensome of these three dietary assessment methods (Wang et al, 2006). 

DietMatePro integrates PDA and web technologies to provide a comprehensive system for monitoring individuals’ dietary intake.  It is based on the USDA Nutrient Database and includes data on approximately 6,600 food items.  Food intake is recorded in real-time and can be transmitted to a health care professional via a palm device or a computer using a web server application.  The system was validated by comparing 3 days continuous recording to 24-hour recalls obtained a day later, and an observed lunch.  Results showed significant correlations between methods (Beasely et al, 2005).

Smart cards
In the UK, the Smart card system was developed, originally as a convenient way to pay for pupil’s meals, although is now also used for monitoring eating behaviours. After registration at the cash register, the card records food details of each transaction and other data including the date and time of purchase. The Smart card technology successfully monitored food choices of over a 1,000 children and demonstrated the potential of the method in such environments (Lambert et al, 2005).

The use of market research data, supermarket loyalty data and receipts are important avenues for the acquisition of food choices data at the household level.

Conclusion
The examples provided in this section indicate the potential technology offers to improve the assessment of dietary intake. 

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