The National Cancer Institute diet history questionnaire: validation of pyramid food servings.
ABSTRACT The performance of the National Cancer Institute's food frequency questionnaire, the Diet History Questionnaire (DHQ), in estimating servings of 30 US Department of Agriculture Food Guide Pyramid food groups was evaluated in the Eating at America's Table Study (1997-1998), a nationally representative sample of men and women aged 20-79 years. Participants who completed four nonconsecutive, telephone-administered 24-hour dietary recalls (n = 1,301) were mailed a DHQ; 965 respondents completed both the 24-hour dietary recalls and the DHQ. The US Department of Agriculture's Pyramid Servings Database was used to estimate intakes of pyramid servings for both diet assessment tools. The correlation (rho) between DHQ-reported intake and true intake and the attenuation factor (lambda) were estimated using a measurement error model with repeat 24-hour dietary recalls as the reference instrument. Correlations for energy-adjusted pyramid servings of foods ranged from 0.43 (other starchy vegetables) to 0.84 (milk) among women and from 0.42 (eggs) to 0.80 (total dairy food) among men. The mean rho and lambda after energy adjustment were 0.62 and 0.60 for women and 0.63 and 0.66 for men, respectively. This food frequency questionnaire validation study of foods measured in pyramid servings allowed for a measure of food intake consistent with national dietary guidance.
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ABSTRACT: Observational evidence from behavioral weight control trials and community studies suggests that greater frequency of weighing oneself, or tracking weight, is associated with better weight outcomes. Conversely, it has also been suggested that frequent weight tracking may have a negative impact on mental health and outcomes during weight loss, but there are minimal experimental data that address this concern in the context of an active weight loss program. To achieve the long-term goal of strengthening behavioral weight loss programs, the purpose of this randomized controlled trial (the Tracking Study) is to test variations on frequency of self-weighing during a behavioral weight loss program, and to examine psychosocial and mental health correlates of weight tracking and weight loss outcomes. Three hundred thirty-nine overweight and obese adults were recruited and randomized to one of three variations on weight tracking frequency during a 12-month weight loss program with a 12-month follow-up: daily weight tracking, weekly weight tracking, or no weight tracking. The primary outcome is weight in kilograms at 24months. The weight loss program integrates each weight tracking instruction with standard behavioral weight loss techniques (goal setting, self-monitoring, stimulus control, dietary and physical activity enhancements, lifestyle modifications); participants in weight tracking conditions were provided with wireless Internet technology (Wi-Fi-enabled digital scales and touchscreen personal devices) to facilitate weight tracking during the study. This paper describes the study design, intervention features, recruitment, and baseline characteristics of participants enrolled in the Tracking Study. Copyright © 2014 Elsevier Inc. All rights reserved.Contemporary Clinical Trials 12/2014; · 1.99 Impact Factor
- American Journal of Clinical Nutrition 11/2014; 100(5):1399-400. · 6.50 Impact Factor
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ABSTRACT: The objective of this study was to compare the usefulness of two methods to evaluate diet quality in young people in Southern Spain: a new Mediterranean Diet Pattern (MDP) and a modification of the Diet Quality Index-International (DQI-I) for the Mediterranean area. The study population was 3190 schoolchildren aged 8-15 yrs. The questionnaires used were first validated (Bland-Altman plot and Wilcoxon tests) in a randomized sample. The DQI gives a more detailed evaluation of food components, whereas the MDS gives global information on food groups but includes foods characteristically consumed in the Mediterranean region. Highly similar results were obtained using the MDP and the adapted DQI-I, which appear to be equally useful to evaluate diet quality in a Mediterranean population. The fact that we selected the same types of food for both indices may explain the similar overall evaluations. According to these results, both methods appear to be equally appropriate for evaluating diet quality in a Mediterranean population.Nutricion hospitalaria: organo oficial de la Sociedad Espanola de Nutricion Parenteral y Enteral 12/2010; 25(6):1006-1013. · 1.25 Impact Factor