Journal of The American Dietetic Association最新文献

Background

Dietary components effective in weight maintenance efforts have not been adequately identified.

Objective

To determine the effects of changes in dietary consumption on weight loss and maintenance during the Weight Loss Maintenance clinical trial.

Design

Weight Loss Maintenance was a randomized controlled trial. Successful weight loss participants who completed Phase I of the trial and lost 4 kg were randomized to one of three maintenance intervention arms in Phase II and followed for an additional 30 months.

Participants/setting

The multicenter trial was conducted from 2003 through 2007. This substudy included 828 successful weight loss participants.

Methods

The Block Food Frequency Questionnaire (FFQ) was used to assess nutrient intake levels and food group servings. Carbohydrates, proteins, fats, dietary fiber, fruit/vegetable, and dairy servings were utilized as predictor variables. The FFQ was collected on all participants at study entry (beginning of Phase I). Those randomized to Phase II completed the FFQ at three additional time points: randomization (beginning of Phase II), 12 months, and 30 months.

Intervention

The main intervention focused on long-term maintenance of weight loss using the Dietary Approaches to Hypertension diet. This substudy examined if changes to specific dietary variables were associated with weight loss and maintenance.

Statistical analyses performed

Linear regression models that adjusted for change in total energy examined the relationship between changes in dietary intake and weight for each time period. Site, age, race, sex, and a race–sex interaction were included as covariates.

Results

Participants who substituted protein for fat lost, on average, 0.33 kg per 6 months during Phase I (P<0.0001) and 0.07 kg per 6 months during Phase II (P<0.0001) per 1% increase in protein. Increased intake of fruits and vegetables was associated with weight loss in Phases I and II: 0.29 kg per 6 months (P<0.0001) and 0.04 kg per 6 months (P=0.0062), respectively, per 1-serving increase. Substitution of carbohydrates for fat and protein for carbohydrates were associated with weight loss during both phases. Increasing dairy intake was associated with significant weight loss during Phase II (−0.17 kg per 6 months per 1-serving increase, P=0.0002), but not during Phase I. Dietary fiber revealed no significant findings.

Conclusions

Increasing fruits, vegetables, and low-fat dairy may help achieve weight loss and maintenance.

Background

Evidence suggests that adequate vitamin D status in infancy plays a role in improving bone health and preventing disease, including type 1 diabetes, infections, and asthma. The objective of this study was to provide newborn hospitalized infants with American Academy of Pediatrics recommendations of 400 IU/day vitamin D-3 and measure the effect on serum 25(OH)D levels.

Design

This trial was conducted August 2009 to June 2010. Infants were randomized to a control were measured from cord blood, every 7 days, and at discharge. Intact parathyroid hormone was measured at discharge.

Participants/setting

Fifty-two infants <32 weeks gestational age who received formula feedings during their neonatal intensive care unit hospitalization.

Statistical analysis

Patient characteristics for each treatment group were summarized using descriptive statistics. The Mann-Whitney test was used to compare continuous variables, and categorical variables were compared using the χ² test or Fisher's exact test. The Pearson correlation coefficient was used to look at associations between continuous variables.

Results

The mean cord blood level for all participants was 17.6±7.0 ng/mL. White infants had significantly higher 25(OH)D levels than non-white infants (P=0.0003). The mean 25(OH)D level at discharge of the supplemented group was 23.1±7.0 ng/mL (57.66±17.47 nmol/L), the mean 25(OH)D level of the unsupplemented group was 17.8±4.7 ng/mL (44.43±11.3 nmol/L), (P=0.007). Serum 25(OH)D showed a positive correlation with serum calcium in the first week of life (r=0.44, P=0.003) and negative correlation with parathyroid hormone levels at discharge (r=−0.35, P=0.02).

Conclusions

In newborn hospitalized infants, vitamin D-3 supplementation of 400 IU/day increased mean 25(OH)D levels from 17 ng/mL at birth to 23.1 ng/mL at discharge. Lower 25(OH)D levels were correlated with hypocalcemia during the first week of life, and elevated parathyroid hormone levels at discharge.

Background

Cancer survivors are at increased risk for secondary cancers and other diseases. Healthy dietary practices may improve cancer survivors' health and well-being.

Objective

The durability of the effects of the FRESH START intervention, a program of sequentially tailored mailed materials, and standardized mailed materials (for controls) on cancer survivors' dietary outcomes was assessed over a 2-year period. Greater dietary gains were expected for FRESH START participants relative to controls.

Design

Participants were randomized to receive tailored vs standardized 10-month mailed print interventions promoting diet and exercise behaviors. Data were collected at baseline and 1- and 2-year follow-ups.

Participants/setting

Breast and prostate cancer survivors (n=543) were recruited from 39 states and two provinces within North America. A total of 489 participants completed the 2-year follow-up assessment (10% attrition).

Intervention

Participants were randomly assigned to either a 10-month program of tailored mailed print materials promoting fruit and vegetable consumption, reduced total and saturated fat intake, and/or increased exercise or to a 10-month program of publicly available mailed materials on diet and exercise.

Main outcome measures

Telephone surveys (supported with blood biomarkers) assessed dietary habits at baseline and 1- and 2-year follow-ups.

Statistical analyses performed

Paired-samples t tests were conducted to examine the durability of the intervention's effects on dietary outcomes within each study arm. Arm differences in follow-up outcomes were then tested with the general linear model, controlling for the baseline value of the outcomes.

Results

Both arms reported decreased saturated fat intake, increased servings of fruits and vegetables, and better overall diet quality at year 2 relative to baseline. However, FRESH START participants reported better overall diet quality and lower total and saturated fat intake compared to controls at the 2-year follow-up.

Conclusions

Results suggest that mailed material interventions, especially those that are tailored, can produce long-term dietary improvement among cancer survivors.

Fortification can help individuals achieve adequate nutritional intake. Foods may be fortified with soy flour as a source of protein for individuals limiting their intake of animal products, either due to personal dietary preference or to reduce their intake of saturated fat, a known risk factor for heart disease. This study determined the feasibility of fortifying peanut butter graham crackers by substituting soy flour for all-purpose wheat flour at 25%, 50%, 75%, or 100% weight/weight. Graham crackers fortified with soy flour were compared to similarly prepared nonfortified peanut butter graham crackers. Moisture contents of all graham crackers were similar. Consumers (n=102) evaluated each graham cracker using a hedonic scale and reported liking the color, smell, and texture of all products. However, unlike peanut butter graham crackers fortified with lower levels of soy, graham crackers fortified with 100% weight/weight soy flour had less than desirable flavor, aftertaste, and overall acceptability. Overall, this study shows that fortification of peanut butter graham crackers up to 75% weight/weight with soy flour for all-purpose wheat flour is acceptable.