Advancing dietary assessment through technology and biomarkers
The inherent complexity and error associated with self-report dietary assessment methods have interfered with establishing the presumed relationships between diet and disease. Current technology including mobile devices with integrated cameras and biomarkers of dietary intakes provide unique means for addressing errors in dietary assessment. The mobile telephone food record (mpFR) is a unique dietary assessment tool in development. The user records foods and beverages in images taken before and after eating. The images can be used for automated food identification and portion size estimation. Using advanced technologies, there is an opportunity to improve estimates of dietary intake. However, the outcomes of mpFR use may be influenced by the interaction of the participant. Thus, the purpose of the studies described in this dissertation is to evaluate the reactivity among adolescents and adults using the mpFR. The objectives of these studies were to: 1) evaluate adolescents' abilities to identify foods and estimate the portion size of foods consumed; 2) investigate the influence of mpFR use among adolescents in a laboratory setting on expected energy intake for individual meals and 24-hour dietary intake; 3) compare reported energy intake from 3 non-consecutive days of mpFR use to estimated energy requirements among adults. Participants included adolescents (n= 78, ages 11-18 y) and adults (n=12, ages 20-58 y) who were recruited from the local community. Data were collected during studies taking place in the laboratory setting for adolescents, and the community dwelling environment for adults. All foods and beverages of known composition and quantity were provided to all participants. Although portion size estimation was a challenge, adolescents were able to correctly identify foods at the time of consumption and when prompted with an image of their meal 14 hours post-prandial. Among adolescents, there was no evidence that use of the mpFR contributed to undereating in the laboratory setting. Furthermore, reported energy intakes of the adults using the mpFR for 3 non-consecutive days were not significantly different from estimated energy requirements. These studies inform the continuing development of the mpFR and suggest that reactivity among users of the mpFR is limited. ^ The development of objective biomarkers will also help improve assessment of dietary intake. Urinary sucrose and fructose, an indicator biomarker of total sugar intake, may help stratify low, medium, and high adolescent consumers of total sugar intakes. The objective of this study was to compare estimates of total sugar intakes to 24-hour urinary sucrose and fructose. Fifteen adolescents (ages 11-18y) were provided 3 meals and ad libitum sweet snacks over a 24-hour period. Gram weights of served foods and plate waste was recorded and nutrient composition was estimated. Urinary sucrose and fructose were significantly correlated with total sugar intakes among these adolescents (r = 0.642; p=0.013; r = 0.579; p= 0.030, respectively). The results of this analysis support urinary sucrose and fructose as indicator biomarkers for stratification of total sugar intakes among adolescents. Together, improvements in dietary assessment methodology along with the use of biomarkers to objectively assess dietary intakes, will lead to a better understanding diet's effect on disease risk and health outcomes.^
Richard Mattes, Purdue University.
Health Sciences, Nutrition
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