Faculty Bibliography

The authors compared effects of macronutrients on self-reported appetite and selected fasting hormone levels. The Optimal Macronutrient Intake Trial to Prevent Heart Disease (OMNI-Heart) (2003-2005) was a randomized, 3-period, crossover feeding trial (n = 164) comparing the effects of 3 diets, each rich in a different macronutrient. Percentages of kilocalories of carbohydrate, fat, and protein were 48, 27, and 25, respectively, for the protein-rich diet; 58, 27, and 15, for the carbohydrate-rich diet; and 48, 37, and 15 for the diet rich in unsaturated fat. Food and drink were provided for each isocaloric 6-week period. Appetite was measured by visual analog scales. Pairwise differences between diets were estimated using generalized estimating equations. Compared with the protein diet, premeal appetite was 14% higher on the carbohydrate (P = 0.01) and unsaturated-fat (P = 0.003) diets. Geometric mean leptin was 8% lower on the protein diet than on the carbohydrate diet (P = 0.003). Obestatin levels were 7% and 6% lower on the protein diet than on the carbohydrate (P = 0.02) and unsaturated-fat (P = 0.004) diets, respectively. There were no between-diet differences for ghrelin. A diet rich in protein from lean meat and vegetables reduces self-reported appetite compared with diets rich in carbohydrate and unsaturated fat and can be recommended in a weight-stable setting. The observed pattern of hormone changes does not explain the inverse association between protein intake and appetite.

OBJECTIVE: To develop and evaluate a pictorial, web-based version of the NCI diet history questionnaire (Web-PDHQ). DESIGN: The Web-PDHQ and paper version of the DHQ (Paper-DHQ) were administered 4 weeks apart with 218 participants randomised to order. Dietary data from the Web-PDHQ and Paper-DHQ were validated using a randomly selected 4 d food record recording period (including a weekend day) and two randomly selected 24 h dietary recalls during the 4 weeks intervening between these two diet history administrations. SETTING: Research office in Reston, VA, USA. PARTICIPANTS: Computer-literate men and women recruited through newspaper advertisements. RESULTS: Mean correlation of energy and the twenty-five examined nutrients between the Web-PDHQ and Paper-DHQ was 0.71 and 0.51, unadjusted and energy-adjusted by the residual method, respectively. Moderate mean correlations (unadjusted 0.41 and 0.38; energy-adjusted 0.41 and 0.34) were obtained between both the Web-PDHQ and Paper-DHQ with the 4 d food record on energy and nutrients, but the correlations between the Web-PDHQ and Paper-DHQ with the 24 h recalls were modest (unadjusted 0.31 and 0.29; energy-adjusted 0.37 and 0.26). A subset of participants (n 48) completing the Web-PDHQ at the initial visit performed a retest on the same questionnaire 1 week later to determine repeatability, and the unadjusted mean correlation was 0.82. CONCLUSIONS: These data indicate that the Web-PDHQ has comparable repeatability and validity to the Paper-DHQ but did not improve the relationship of the DHQ to other food intake measures (e.g. food records, 24 h recall).

OBJECTIVE: To evaluate the capability of DietMatePro, a PDA-based dietary assessment program, to monitor dietary intake and to improve adherence to a dietary regimen. DESIGN: Randomized controlled trial. SUBJECTS: Overweight and obese (Body Mass Index (BMI) 25-40) participants without dietary restrictions. INTERVENTION: Participants (n = 174) were randomized to record usual dietary intake using either DietMatePro or a paper food diary for one week to compare concordance with 24-hr recall. At the week 1 visit, participants were individually counseled to follow the diet recommendations of the Ornish Prevention Diet for three weeks and continue monitoring food intake using the assigned method to estimate adherence to the intervention by monitoring condition. OUTCOME MEASURES: Spearman correlations between week 1 24-hr recall and the assigned recording method were compared to assess validity. Mean pre-post changes in intake measured by 24-hr recall were compared according to monitoring condition to measure adherence to the Ornish diet. RESULTS: Correlations of energy and nutrient values reported on the food label ranged from 0.41 to 0.71 for the DietMatePro condition versus 0.63 to 0.83 for the paper-based diary. Diet adherence was higher among DietMatePro (43%) compared to the paper diary (28%) group (p = 0.039). CONCLUSIONS/APPLICATIONS: DietMatePro does not appear to produce more valid data than paper-based approaches. DietMatePro may improve adherence to dietary regimens compared to paper-based methods.

CONTEXT: Recent developments in genetic testing allow us to detect individuals with inherited susceptibility to some cancers. Genetic testing to identify carriers of cancer-related mutations may help lower risk by encouraging preventive behaviors and surveillance. This study assessed willingness of colon cancer cases and relatives to receive genetic information that may indicate an increased risk for cancer, to whom they would disclose genetic information, and whether receiving genetic test results may influence future prevention behaviors among individuals enrolled in the Seattle Colorectal Cancer Family Registry. METHODS: Incident invasive colorectal cancer cases were identified from the Puget Sound Surveillance Epidemiology and End Results (SEER) registry. In 2007, a sequential sample of cases and relatives (n = 147) were asked to respond to a questionnaire addressing study aims. The questionnaire was administered during a baseline or 5-year follow-up interview. RESULTS: Patterns of response to each statement were similar between colorectal cancer cases and relatives. Both colorectal cases (95%) and relatives (95%) reported willingness to receive genetic information. Nearly all participants would tell their doctor the results of a genetic test (99% of cases; 98% of relatives), and all married participants would tell their spouses. Cases (96%) anticipated being slightly more likely than relatives (90%) to change their cancer screening behavior, but this difference was not statistically significant (p = 0.33). CONCLUSIONS: A high percentage of both colorectal cancer cases and relatives sampled from the Seattle Colorectal Cancer Family Registry are interested in identifying their genetic status, discussing their genetic status with their family and doctor, and adopting behavioral changes that may reduce cancer risk.

OBJECTIVE: Assess the effects of a prototype computerized food portion tutorial (CFPT). DESIGN: Participants were randomly assigned to estimate portion sizes for selected food items either prior to or following CFPT training (between groups), and those estimating before CFPT training re-estimated portions after training (within groups). SETTING: Research offices. PARTICIPANTS: Seventy-six adult participants without dietary restrictions. INTERVENTION: The CFPT is a Web-based food portion training program that displays varied portions of 23 food items with user-controllable reference objects and viewing angles. MAIN OUTCOME MEASURES: Estimated vs. weighed portions of food items selected for a meal. ANALYSIS: Nonparametric tests were performed on estimated vs. weighed portion differences and on accuracy ratios between and within groups. RESULTS: A significant difference was found between conditions, both within and between groups, on the discrepancy between estimated and weighed portions for a number of the food items. Training exposure, however, resulted primarily in a shift from underestimation to overestimation, not more accurate estimation. IMPLICATIONS FOR RESEARCH AND PRACTICE: The CFPT produced a significant impact on food portion estimation but appeared to sensitize participants to underestimation errors, leading to overestimation errors. Computerization of food portion training programs holds promise for providing cost-efficient portion estimation training but requires further development and evaluation before being considered for clinical use.

OBJECTIVE: Study objectives were to assess the accuracy of a food record delivered on a personal digital assistant (PDA) and to examine sources of error from the PDA-based food record. METHODS: Thirty-nine adults recruited with a newspaper advertisement were trained to record food intake using DietMatePro, a dietary assessment program delivered on a PDA. After 3 d of use, subjects returned for a follow-up visit in which a 24-h recall was conducted. Subjects also were timed while recording an observed, weighed lunch. Recalled and actual food intakes were compared with estimates recorded by the subjects when using the PDA. Paired sample t tests and Pearson's correlations assessed means and measurements of association between DietMatePro data compared with the 24-h recall data and observed meal data. Bland-Altman plots were used to assess bias in food recording. Sources of error were quantified by using calories as the unit for comparison. RESULTS: There were no significant differences in daily totals for calories and macronutrients between DietMatePro data and comparison measurements. Pearson's correlations of associations between DietMatePro data and the comparison measurement ranged from 0.505 to 0.797 (P < 0.005, n = 28) for the 24-h recall and from 0.419 to 0.786 (P < 0.005, n = 33) for the observed lunch, depending on the nutrient measured. The largest source of absolute error in caloric estimation was attributable to portion size estimation error (49%). CONCLUSIONS: DietMatePro, a PDA-based dietary assessment program, provides a method of assessing energy and macronutrient intakes comparable to the 24-h recall in samples lacking dietary restrictions.