Can individuals meet multiple physical activity and dietary behavior goals?

OBJECTIVES: To examine whether participants with the most behavioral goals to achieve were more likely to meet more goals than those given fewer goals. METHODS: Eight hundred ten participants were randomly assigned to advice-only, established guidelines for blood pressure control (reduced sodium, increased physical activity), or established guidelines plus the DASH diet (increased fruits, vegetables, low-fat dairy, reduced fat). RESULTS: At 6 months, 11.7% of Advice-Only, 19.3% of Established, and 44.6% of Established plus DASH met at least 3 goals (P<0.0001). At 18 months, 33.5% of Established plus DASH met at least 3 goals. CONCLUSIONS: Those with the most goals to achieve reached the most goals.

PREMIER--a trial of lifestyle interventions for blood pressure control: intervention design and rationale.

Interventions encouraging adoption of healthy diets and increased physical activity are needed to achieve national goals for preventing and treating hypertension, cardiovascular disease, diabetes, and other chronic diseases. PREMIER was a multicenter clinical trial testing the effects of two lifestyle interventions on blood pressure control, compared with advice only. Both interventions implemented established national guidelines for blood pressure control (weight loss, reduced sodium and alcohol intake, and increased physical activity), and one intervention also included the Dietary Approaches to Stop Hypertension (DASH) diet. Both interventions focused on behavioral self-management, motivational enhancement, and personalized feedback. This article describes the design and evaluation approaches for these interventions. Evaluation of multicomponent lifestyle change interventions can help us understand the benefits and difficulties of making multiple lifestyle changes concurrently and the effects such changes can have on blood pressure, particularly in minorities at higher risk for hypertension.

The PREMIER intervention helps participants follow the Dietary Approaches to Stop Hypertension dietary pattern and the current Dietary Reference Intakes recommendations.

OBJECTIVE: To examine the influence of the PREMIER study lifestyle interventions on dietary intakes and adherence to the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and the Dietary Reference Intakes (DRI). DESIGN: An 18-month multicenter, randomized controlled trial comparing two multicomponent lifestyle intervention programs to an advice only control group. SUBJECTS/SETTING: A total of 810 participants were recruited from local communities and randomized into the study. Individuals were eligible if they were aged 25 years or older, had body mass index between 18.5 and 45.0, not taking antihypertensive medication, and had prehypertension or stage 1 hypertension (systolic blood pressure 120 to 159 mm Hg and diastolic blood pressure 80 to 95 mm Hg). INTERVENTION: The two active intervention programs were a behavioral lifestyle intervention that implements established recommendations, and an established intervention plus the DASH dietary pattern. Both interventions consisted of intensive group and individual counseling sessions. The control group received a brief advice session after randomization and again after 6 months of data collection. Dietary intakes were collected by two random 24-hour recalls at baseline, 6 months, and 18 months. MAIN OUTCOME MEASURES: The primary outcome of the PREMIER study was change in systolic blood pressure at 6 months. The main outcomes examined here include dietary variables collected by 24-hour recall at each time point. STATISTICAL ANALYSES: Nutrient intakes were calculated and compared among the time points and the three intervention groups using mixed models with repeated measures at 6 and 18 months. Proportion of participants who met or achieved the original DASH nutrient intake levels and the DRIs were calculated and compared among the three intervention groups. P<0.01 was considered statistically significant. RESULTS: Participants in both the established intervention and established intervention plus DASH dietary pattern groups substantially reduced energy, total fat, saturated fat, and sodium intake and these reductions persisted throughout the study. Established intervention plus DASH dietary pattern group participants increased intakes of fruits, vegetables, dairy, and many vitamins and minerals; these increases were significantly greater than that of the control and established intervention groups. A majority of established intervention plus DASH dietary pattern group participants achieved at least two thirds of the DRI recommendations for most nutrients at 6 months, despite their reduction in total energy intake. Some but relatively small recidivism occurred at 18 months. CONCLUSIONS: Both the established intervention and established intervention plus DASH dietary pattern group intervention were effective in helping participants follow established recommendations to control blood pressure. The advice-only control group also made some behavior changes, mainly decreasing energy and sodium intake. Only the established intervention plus DASH dietary pattern group significantly increased intakes of DASH-specific food groups, including fruits, vegetables, and dairy products, and nutrients, including protein, fiber, calcium, potassium, and magnesium. Most of the increases did not reach the levels consumed in the original DASH feeding studies. Whereas the established intervention plus DASH dietary pattern group intervention provides a useful platform to achieve the DASH dietary pattern and current DRI recommendations, intervention enhancements, including a greater emphasis on nutrient-dense foods, would likely improve this intervention.

The DASH diet and blood pressure.

High blood pressure (also called hypertension) is one of the most important and common risk factors for atherosclerotic cardiovascular disease (CVD) and other chronic diseases. National guidelines recommend that all individuals with blood pressure readings of 120/80 mm Hg or higher adopt healthy lifestyle habits, including the Dietary Approaches to Stop Hypertension (DASH) diet, to manage their blood pressure. The DASH diet, which is high in fruits, vegetables, and low-fat dairy products and reduced in fat, has been shown in large, randomized, controlled trials to reduce blood pressure significantly. The DASH diet also has been shown to reduce blood cholesterol and homocysteine levels and to enhance the benefits of antihypertensive drug therapy. The DASH diet should be promoted, along with maintaining healthy weight, reducing sodium intake, increasing regular physical activity, and limiting alcohol intake, for lowering blood pressure and reducing the risk of CVD.

Dietary quality assurance processes of the DASH-Sodium controlled diet study.

A thorough quality assurance (QA) program upholds the integrity of nutrition research studies by yielding reliable data and results. Continually evaluating the implementation of a procedure against a goal and making adjustments when needed enhance the quality of a study's conduct and outcomes. Controlled diet studies require QA processes at various steps beginning with the screening of study participants, through diet preparation and delivery to data collection. Staff training and observations with monitoring activities, are important so tasks are completed according to protocol. When several clinical sites participate as partners in a controlled diet study, uniform procedures must be followed and a formal standardized QA program will assist. The Dietary Approaches to Stop Hypertension (DASH)-Sodium study employed such a program, described in this article, that included training staff, observing procedures, monitoring data for completeness and accuracy, evaluating processes, giving feedback, and documenting that tasks were done according to protocol. Furthermore, QA processes were used in the areas of participant screening, orientation, diet adherence, food procurement and preparation, and exit interviews. Other researchers may implement similar activities to ensure quality in their nutrition research programs.

Food group sources of nutrients in the dietary patterns of the DASH-Sodium trial.

The aim of this paper is to identify major food group sources of several essential nutrients in the two dietary patterns used in the DASH-Sodium trial: a control diet and the DASH dietary pattern. The DASH-Sodium trial was a multicenter, randomized, controlled-feeding trial comparing the effects of three levels of sodium and two dietary patterns on blood pressure. Nutrient contents of all the menus for both the control and the DASH diets were analyzed and examined for their dietary sources from 13 food groups. Contributions of all foods within each food group to each nutrient were averaged then weighted to reflect the actual distribution of energy levels in the study. Nutrient contents across the three sodium levels are very similar within each diet. Refined grains and whole grains are the major energy sources for the control and the DASH diet, providing 35% and 23% to the total intake, respectively. Nutrient-dense whole grains contributed greatly, ranging from 11% to 46%, to the higher intakes of protein, fiber, calcium, magnesium, potassium, zinc, and folate in the DASH diet. Vegetables, in addition to being a good source for fiber, vitamins A, C, E, and folate, also contributed an average of 15% to the intakes of magnesium, potassium, and calcium in the DASH diet. Differences in nutrient contents between the control and the DASH diets were accomplished by varying the selection of food items (eg, refined grains vs whole grains) and quantities of certain food groups (eg, less red meats and higher amounts of fruits and vegetables). The DASH dietary pattern recommends four to five servings of fruits; four to five servings of vegetables; two to three servings of low-fat dairy products; seven to eight servings of grain products (preferably whole grains); two or less servings of meats, poultry, and fish per day; and four to five servings of nuts, seeds, and legumes per week for a 2,000 kcal diet. Each of these food groups contributes critical nutrients across various sodium levels. It is important to emphasize all food groups when trying to follow this proven dietary pattern.