Journal of The American Dietetic Association最新文献

Background

There is no consensus as to whether low dietary intakes of saturated fat or cholesterol, or high intakes of dietary fiber are related to a lower prevalence of metabolic syndrome (MetS) in adolescent children.

Objective

To determine whether a fiber-rich diet as measured by a fiber index (grams fiber/1,000 kcal) is associated with lower rates of MetS among adolescents vs a diet low in saturated fat or cholesterol as measured by a saturated fat index (grams saturated fat/1,000 kcal) and a cholesterol index (milligrams cholesterol/1,000 kcal), respectively.

Design/participants/setting

Cross-sectional analysis of 12- to 19-year-old boys and girls (N=2,128) who participated in the National Health and Nutrition Examination Survey 1999-2002.

Outcomes and statistical analyses

The prevalence of MetS (abnormal values of three or more of the following: waist circumference, blood pressure, fasting serum high-density lipoprotein cholesterol, triglycerides, and glucose) was compared across quintiles of the dietary indexes (fiber index, saturated fat index, and cholesterol index) derived from 24-hour recalls. χ² tests determined the prevalence across dietary quintiles, and multivariate logistic regression evaluated the association of the dietary indexes with MetS. Weighted analyses were used controlling for sex, age, ethnicity, and family income. Significance was set at P≤0.05.

Results

The overall prevalence of MetS was 6.4% (n=138). There was a graded inverse association between the fiber index and MetS (P<0.001) with a threefold difference between the lowest and highest quintiles (9.2% vs 3.1%). Each quintile increase in the fiber index was associated with a ∼20% decrease in MetS (adjusted odds ratio 0.83, 95% confidence interval 0.68-1.00; P≤0.043). Neither the saturated fat index (P=0.87) nor the cholesterol index (P=0.22) was significantly associated with MetS.

Conclusions

Higher intakes of dietary fiber, but not low intakes of saturated fat or cholesterol are related to the MetS in adolescents. These findings suggest that to reduce the risks for MetS in adolescents, it is more important to emphasize a paradigm that promotes the inclusion of fiber-rich, nutrient-dense, plant-based foods vs what foods to restrict or exclude as is commonly done when the focus is on total fat, cholesterol, or saturated fat intake.

Background

Nutrition Facts labels can keep consumers better informed about their diets' nutritional composition, however, consumers currently do not understand these labels well or use them often. Thus, modifying existing labels may benefit public health.

Objective

The present study tracked the visual attention of individuals making simulated food-purchasing decisions to assess Nutrition Facts label viewing. Primary research questions were how self-reported viewing of Nutrition Facts labels and their components relates to measured viewing and whether locations of labels and specific label components relate to viewing.

Design

The study involved a simulated grocery shopping exercise conducted on a computer equipped with an eye-tracking camera. A post-task survey assessed self-reported nutrition information viewing, health behaviors, and demographics.

Subjects/setting

Individuals 18 years old and older and capable of reading English words on a computer (n=203) completed the 1-hour protocol at the University of Minnesota during Spring 2010.

Statistical analyses

Primary analyses included χ², analysis of variance, and t tests comparing self-reported and measured viewing of label components in different presentation configurations.

Results

Self-reported viewing of Nutrition Facts label components was higher than objectively measured viewing. Label components at the top of the label were viewed more than those at the bottom, and labels positioned in the center of the screen were viewed more than those located on the sides.

Conclusions

Nutrition Facts label position within a viewing area and position of specific components on a label relate to viewing. Eye tracking is a valuable technology for evaluating consumers' attention to nutrition information, informing nutrition labeling policy (eg, front-of-pack labels), and designing labels that best support healthy dietary decisions.

Obesity disproportionately affects low-income and minority individuals and has been linked with food insecurity, particularly among women. More research is needed to examine potential mechanisms linking obesity and food insecurity. Therefore, this study's purpose was to examine cross-sectional associations between food insecurity, Supplemental Nutrition Assistance Program (SNAP) benefits per household member, perceived stress, and body mass index (BMI) among female SNAP participants in eastern North Carolina (n=202). Women were recruited from the Pitt County Department of Social Services between October 2009 and April 2010. Household food insecurity was measured using the validated US Department of Agriculture 18-item food security survey module. Perceived stress was measured using the 14-item Cohen's Perceived Stress Scale. SNAP benefits and number of children in the household were self-reported and used to calculate benefits per household member. BMI was calculated from measured height and weight (as kg/m²). Multivariate linear regression was used to examine associations between BMI, SNAP benefits, stress, and food insecurity while adjusting for age and physical activity. In adjusted linear regression analyses, perceived stress was positively related to food insecurity (P<0.0001), even when SNAP benefits were included in the model. BMI was positively associated with food insecurity (P=0.04). Mean BMI was significantly greater among women receiving <$150 in SNAP benefits per household member vs those receiving ≥$150 in benefits per household member (35.8 vs 33.1; P=0.04). Results suggest that provision of adequate SNAP benefits per household member might partially ameliorate the negative effects of food insecurity on BMI.

Eating frequency has been negatively related to body mass index (BMI). The relationship between eating frequency and weight loss maintenance is unknown. This secondary analysis examined eating frequency (self-reported meals and snacks consumed per day) in weight loss maintainers (WLM) who had reduced from overweight/obese to normal weight, normal weight (NW) individuals, and overweight (OW) individuals. Data collected July 2006 to March 2007 in Providence, RI, included three 24-hour dietary recalls (2 weekdays, 1 weekend day) analyzed using Nutrient Data System for Research software from 257 adults (WLM n=96, 83.3% women aged 50.0±11.8 years with BMI 22.1±1.7; NW n=80, 95.0% women aged 46.1±11.5 years with BMI 21.1±1.4; OW n=81, 53.1% women aged 51.4±9.0 years with BMI 34.2±4.1) with plausible intakes. Participant-defined meals and snacks were ≥50 kcal and separated by more than 1 hour. Self-reported physical activity was highest in WLM followed by NW, and then OW (3,097±2,572 kcal/week, 2,062±1,286 kcal/week, and 785±901 kcal/week, respectively; P<0.001). Number of daily snacks consumed was highest in NW, followed by WLM, and then OW (2.3±1.1 snacks/day, 1.9±1.1 snacks/day, and 1.5±1.3 snacks/day, respectively; P<0.001). No significant group differences were observed in mean number of meals consumed (2.7±0.4 meals/day). Eating frequency, particularly in regard to a pattern of three meals and two snacks per day, may be important in weight loss maintenance.

Despite interventions designed to change behavior, many adolescents continue to consume unhealthy foods. Dietary patterns are important for disease prevention, making it necessary to understand the reasons for these poor choices. This cross-sectional study explored the relationship between perception of dietary practices and dietary behaviors among adolescents. Participants (n=15,283; mean age=15 years; 50.7% female) completed the 2004-2005 Texas School Physical Activity and Nutrition survey. Perception of dietary practices included fat content of foods usually eaten and healthiness of usual eating habits. Dietary behavior was measured by self-report of foods eaten the day before survey administration. Composite scores of unhealthy and healthy eating were created. Regression analyses examined whether perception of dietary practices was consistent with actual dietary behavior, controlling for sex, grade, and race/ethnicity, and accounting for the complex sampling design. Higher perceived fat content was associated with increased consumption of unhealthy foods, while higher perceived healthiness of eating was associated with increased consumption of healthy foods. For perceived fat content, the difference in the Healthy Eating Index between extreme categories was 26% (P<0.001), while the difference in the Unhealthy Eating Index between extreme categories was 81% (P<0.001). For perceived healthiness, the difference in the Healthy Eating Index between extreme categories was 23% (P<0.001), while the difference for the Unhealthy Eating Index was 44% (P<0.001). Self-perceptions of dietary practices were significantly associated with dietary behaviors, indicating awareness about the relative nutrient content of foods consumed. Interventions that move beyond dietary knowledge and create changes in the social and physical environment are needed.