Assessment of Dietary Intake Using Food Photography and Video Recording in Free-Living Young Adults: A Comparative Study.

BACKGROUND: Conventional methods of dietary assessment are prone to recall bias and place burden on participants. OBJECTIVE: Our aim was to compare the performance of image-based dietary assessment (IBDA), including food photography (FP) and video recording (VR), with the criterion of weighed food records (WFR). DESIGN: In this comparative study, participants captured meals using FP and VR before and after consumption, over 2 days. Food type and portion size were assessed using the images and videos. Energy and nutrient intakes (mean of 2 days) were compared against WFR. PARTICIPANTS/SETTINGS: Eighty-four healthy adults (mean [standard deviation] age = 29 [8] years), recruited through advertisement in Glasgow, UK, between January and August 2016 were enrolled in the study. Eighty participants (95%) (mean [standard deviation] age = 28 [7] years) completed the study and were included in the analysis. MAIN OUTCOME MEASURES: Agreement in estimated energy and nutrient intake between WFR and IBDA. The IBDA method feasibility was evaluated using a questionnaire. Inter-rater and intra-rater reliability were assessed. STATISTICAL ANALYSIS PERFORMED: The performance of the IBDA methods against WFR and their inter and intra-rater reliability were tested with Bland-Altman plots and Spearman correlations. Intra-class agreement between methods was assessed using κ statistics. RESULTS: Inter-rater reliability was strong for both IBDA methods in estimating energy intake (ρ-coefficients: FP = 0.80; VR = 0.81). There was no difference in the agreement between the 2 assessors. Intra-rater reliability was high. FP and VR underestimated energy intake by a mean (95% agreement limits) of -13.3% (-56.4% and 29.7%) and -4.5% (-45.5% and 36.4%), respectively. IBDA demonstrated moderate-to-strong correlations in nutrient intake ranking, median ρ-coefficients for all nutrients: FP = 0.73 (interquartile range, 0.09) and VR = 0.82 (interquartile range, 0.02). Inter-class agreement of IBDA methods was moderate compared with the WFR in energy intake estimation. IBDA was more practical and enjoyable than WFR. CONCLUSIONS: IBDA and VR in particular demonstrated a moderate-to-strong ability to rank participants' dietary intake, and considerable group and inter-class agreement compared with the WFR. However, IBDA was found to be unsuitable for assessment in individuals.

Agreement in participant-coded and investigator-coded food-record analysis in overweight research participants: an examination of interpretation bias.

Validation studies support the use of self-administered computerized methods for reporting energy intake; however, the degree of interpretation bias with these methods is unknown. This research compared nutrient intake for food records that were both participant coded (using the National Cancer Institute's Automated Self-Administered 24-hour recall [ASA24] online program) and investigator-coded (a single investigator coded all food records using the ESHA Food Processor diet analysis program). Participants (n=28; mean age=41±11 years; mean body mass index=31±6) were participants in an 8-week trial (conducted between March 2011 and June 2011 in Phoenix, AZ) investigating the impact of meal preloads on satiety. Food records were collected on four occasions during the trial and, of the food records available for this investigation (n=161), 88% were completed on a weekday. Intra-class correlation coefficients were computed for selected nutrients and ranged from 0.65 to 0.81 for the macronutrients and from 0.50 to 0.66 for the micronutrients (overall mean=0.67). Overall mean coefficient improved to 0.77 when the data from three or more food records per participant were averaged, as is commonly done in nutrition research. All intra-class correlation coefficients were significant (P<0.020) and were not impacted by the day of week that food was recorded. For energy, macronutrients, and minerals, the percent median differences between coders were <±17%; however, percent median differences were large for vitamin C (+27%) and beta carotene (+294%). Findings from this study suggest that self-administered dietary assessment has merit as a research tool. Pretrial training for research participants is suggested to reduce interpretation bias.

The effect of peanut and grain bar preloads on postmeal satiety, glycemia, and weight loss in healthy individuals: an acute and a chronic randomized intervention trial.

BACKGROUND: Peanut consumption favorably influences satiety. This study examined the acute effect of peanut versus grain bar preloads on postmeal satiety and glycemia in healthy adults and the long-term effect of these meal preloads on body mass in healthy overweight adults. METHODS: In the acute crossover trial (n = 15; 28.4 ± 2.9 y; 23.1 ± 0.9 kg/m2), the preload (isoenergetic peanut or grain bar with water, or water alone) was followed after 60 min with ingestion of a standardized glycemic test meal. Satiety and blood glucose were assessed immediately prior to the preload and to the test meal, and for two hours postmeal at 30-min intervals. In the parallel-arm, randomized trial (n = 44; 40.5 ± 1.6 y, 31.8 ± 0.9 kg/m2), the peanut or grain bar preload was consumed one hour prior to the evening meal for eight weeks. Body mass was measured at 2-week intervals, and secondary endpoints included blood hemoglobin A1c and energy intake as assessed by 3-d diet records collected at pre-trial and trial weeks 1 and 8. RESULTS: Satiety was elevated in the postprandial period following grain bar ingestion in comparison to peanut or water ingestion (p = 0.001, repeated-measures ANOVA). Blood glucose was elevated one hour after ingestion of the grain bar as compared to the peanut or water treatments; yet, total glycemia did not vary between treatments in the two hour postprandial period. In the 8-week trial, body mass was reduced for the grain bar versus peanut groups after eight weeks (-1.3 ± 0.4 kg versus -0.2 ± 0.3 kg, p = 0.033, analysis of covariance). Energy intake was reduced by 458 kcal/d in the first week of the trial for the grain bar group as compared to the peanut group (p = 0.118). Hemoglobin A1c changed significantly between groups during the trial (-0.25 ± 0.07% and -0.18 ± 0.12% for the grain bar and peanut groups respectively, p = 0.001). CONCLUSIONS: Compared to an isoenergetic peanut preload, consumption of a grain bar preload one hour prior to a standardized meal significantly raised postmeal satiety. Moreover, consumption of the grain bar prior to the evening meal was associated with significant weight loss over time suggesting that glycemic carbohydrate ingestion prior to meals may be a weight management strategy.