Assessing the influence of fasted and postprandial states on day-to-day variability of appetite and food preferences.

Introduction: Ratings of subjective appetite and food hedonics provide valuable information about energy and macronutrient intake. Ensuring reproducibility of measures of subjective appetite, and food liking and wanting is essential for accurate understanding about their implementation in intervention studies.

Methods: Nineteen participants participated in two separate 10-h test days consisting of 6 test meals. Subjective appetite was measured in the fasted state and periodically across the test day in a postprandial state. Liking and wanting were measured using the Leeds Food Preferences Questionnaire (LFPQ) immediately before and after breakfast, immediately before the second meal, and at the end of the test day.

Results: Reproducibility of appetite scores was similar to those previously reported in males, however females tended to have consistently higher CVs, wider CRs and wider 95% CIs. Variability in food hedonics was of a similar magnitude to subjective appetite with CVs for fasting explicit liking and wanting between 15.3 and 33.4%, correlations for both implicit and explicit liking and wanting between 0.18 and 0.87 and CRs indicating 95% of between-day changes for any given individual should fall within ±43.4 mm of the mean change. Averages of food hedonics during the test day reduced CVs, improved correlations and reduced CRs. Despite no mean change in preceding energy and nutrient intake, individual changes in prior energy and macronutrient intake appeared to influence individual between-day changes in appetite and food hedonics, and appetite and food hedonics were intricately linked.

Conclusions: Larger subject numbers may be required for appetite studies with female participants due to greater appetite variability. The LFPQ as a tool for measuring implicit and explicit liking and wanting is sufficiently reproducible and improved by averaging multiple measures across a day.