Dietary misreporting: a comparative study of recalls vs energy expenditure and energy intake by doubly-labeled water in older adults with overweight or obesity

Abstract

Background: Self-report methods are widely used to assess energy intake but are prone to measurement errors. We aimed to identify under-reported, over-reported, and plausible self-reported energy intake by dietary recalls (rEI) using a standard method (Method 1) that calculates the rEI ratio against measured energy expenditure (mEE) by doubly-labeled water (DLW), and compare it to a novel method (Method 2), which calculates the rEI ratio against measured energy intake (mEI) by the principle of energy balance (EB = mEE + changes in energy stores).

Methods: The rEI:mEE and rEI:mEI ratios were assessed for each subject. Group cut-offs were calculated for both methods, using the coefficient of variations of rEI, mEE, and mEI. Entries within ± 1SD of the cutoffs were categorized as plausible, < 1SD as under-reported, and > 1SD as over-reported. Kappa statistics was calculated to assess the agreement between both methods. Percentage bias (bβ) was estimated by linear regression. Remaining bias (dβ) was calculated after applying each method cutoffs.

Results: The percentage of under-reporting was 50% using both methods. Using Method 1, 40.3% of recalls were categorized as plausible, and 10.2% as over-reported. With Method 2, 26.3% and 23.7% recalls were plausible and over-reported, respectively. There was a significant positive relationship between mEI with weight (ß = 21.7, p < 0.01) and BMI (ß = 48.8, p = 0.04), but not between rEI with weight (ß = 13.1, p = 0.06) and BMI (ß = 41.8, p = 0.11). The rEI relationships were significant when only plausible entries were included using Method 1 (weight: ß = 17.4, p < 0.01, remaining bias = 49.5%; BMI: ß = 44.6, p = 0.01, remaining bias = 60.2%) and Method 2 (weight: ß = 19.5, p < 0.01, remaining bias = 24.9%; BMI: ß = 44.8, p = 0.03, remaining bias = 56.9%).

Conclusions: The choice of method significantly impacts plausible and over-reported classification, with the novel method identifying more over-reported entries. While rEI showed no relationships with anthropometric measurements, applying both methods reduced bias. The novel method showed greater bias reduction, suggesting that it may have superior performance when identifying plausible rEI.

Clinical trials registration: NCT04465721.

Keywords: Bias; Dietary misreporting; Dietary recall; Doubly labeled water; Energy intake; Goldberg cutoff; Nutrition assessment; Self-report.

Fig. 1

Box plots of measured energy expenditure (mEE), measured energy intake (mEI), and average reported energy intake (rEI). The median value is indicated by the horizontal line, and the mean value is marked with an “x” within each box. The whiskers represent the minimum and maximum values excluding outliers. Outliers are shown as individual points outside of the boxes. The sign test was used to compare non-parametric paired variables

Fig. 2

Bland–Altman plot of ratios correlation. Bland–Altman plot of ratio comparing Method 1 and Method 2 ratios. The x-axis represents the average of the measurements of the Method 1 and Method 2 ratios, and the y-axis represents the difference between the measurements. The mean difference between both methods was 0.089, and the 95% limits of agreement were − 0.25 and 0.424, suggesting that 95% of the differences between the two methods fell within this range. The plot exhibited a heteroscedastic pattern, suggesting lower agreement between the two methods at higher ratio values, consistent with differing identification of over-reporting. Abbreviations: SD, standard deviation

Fig. 3

Measured energy intake (mEI) and average reported energy intake (rEI) data before and after the Method 1 and Method 2 application. Linear regression models with mEI and rEI data before and after the Method 1 and Method 2 were applied in the entire group, males and females. Abbreviations: BMI, body mass index; cm, centimeters; FM, fat mass; kg, kilograms; mEI, measured energy intake; rEI, reported energy intake