Cancer, Heart Disease
Conditions
Keywords
Nutrition, Dietary Quality, Weight loss
Brief summary
We hypothesize that adding beneficial high fiber foods to the diet will result in better overall dietary quality (measured by the Alternate Healthy Eating Index), which has been shown to be associated with cancer, than either reducing saturated fat, or a combination of high fiber and low saturated fat.
Detailed description
Summary of Grant: Several studies have demonstrated that poor dietary quality is associated with obesity and certain cancers, such as gastrointestinal, colorectal, and hormonal cancers. Dietary interventions aimed at improving diet are plagued by poor adherence, possibly due to the complexity of changing multiple diet components. Complex public health messages are associated with worse adherence and reduced capacity to impact health outcomes. If a simple public health recommendation for diet was effective at changing multiple aspects of diet, adherence and impact could be maximized. However, research has yet to test which single dietary message has the greatest impact on overall diet quality, and consequently, potential for cancer and heart disease prevention. Thus far, dietary interventions have tested varying combinations of multiple recommendations; however, a single dietary recommendation may have a synergistic beneficial effect on other areas of diet, precluding the need to make the message overly complex. The present study compares 3 dietary change conditions that are hypothesized to have high potential for synergistic effects on other unaddressed areas of diet, and consequently overall dietary quality. Patients were randomized to one of three arms: 1. low saturated fat diet (≤7% of total calories); 2. high fiber diet (≥30 grams of total fiber per day); 3. combination arm: low saturated fat and high fiber. Each participant was instructed to reduce calories by -500 kcal/day from his/her resting metabolic rate (RMR), but total calories was not less than 1200 calories per day. Additionally, Dr. Ira Ockene, professor of medicine, director of preventive cardiology program, generously offered to pay for blood draws and blood lipids and glucose analysis at each visit to make the study valuable from both cancer and heart disease research perspectives. Specific aims: 1. Develop intervention materials. Intervention materials that specifically aid participants towards a low saturated fat or high fiber diet, or combination change developed for each condition. 2. Preliminary test of intervention. We will calculate change in diet quality, lipids, body weight, waist circumference, and blood pressure at 3- and 6-months. We hypothesize that the single change conditions will produce more changes than the complex condition and that adding beneficial high fiber foods to the diet will result in improved dietary quality (measured by the Alternative Healthy Eating Index) than reducing saturated fat. Secondary outcomes include calorie intake, micro- and macronutrients at baseline, physical activity, and observe changes at 3- and 6-months. 3. Adherence. We will examine adherence to the treatment protocol so that appropriate adjustments to the intervention can be made, if necessary, to enhance adherence in the larger randomized clinical trial. 4. Data for sample size estimation. We will document means and standard deviations on measures so that sample size can be estimated for the larger randomized clinical trial.
Interventions
BEHAVIORALCombination diet
combination low saturated fat high fiber diet, with calorie restriction as specified.
BEHAVIORALHigh Fiber Diet
high fiber diet (≥30 grams of total fiber per day); reduction of calories to -500 from resting metabolic rate (RMR), not less than 1200 kcal per day.
BEHAVIORALlow saturated fat diet
low saturated fat diet (≤7% of total calories); -500 calories from RMR, not less than 1200 kcal/day.
Sponsors
American Cancer Society, Inc.
University of Massachusetts, Worcester
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
1. BMI ≥25, and ≤40. 2. \>=21 years of age, less than 81 years of age. 3. has primary care physician's approval to participate in all aspects of the study, 4. speaks, reads, and understands English at 6th grade level minimum 5. residing in local area for the duration of the study. 6. available for bi-monthly sessions (6 individual nutrition counseling visits)
Exclusion criteria
1. presence of a psychological disorder that will limit his/her ability to participate (such as an eating disorder, uncontrolled bipolar disorder) 2. unwilling to provide informed consent 3. presence of unstable medical disorder (e.g., uncontrolled hypertension, uncontrolled diabetes, etc), or a medical disorder associated with a life expectancy less than 2 years. 4. currently taking any medication known to affect weight or appetite 5. smokes more than 3 cigarettes a day on average 6. Has a dietary restriction that precludes changing to the healthy diet, i.e.; Crohn's disease, ulcerative colitis, renal disease, active diverticulitis, etc. 7. currently following a specific diet plan (low saturated fat/meat, or high fiber) 8. does not have a telephone 9. Pregnant, or planning to become pregnant (participant will be asked this question in telephone screening. If the participant becomes pregnant, they are asked to inform the principal investigator) 10. Has an active drug or alcohol problem within the past year -
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Dietary Quality | 6 mos | Dietary quality was measured by the Alternative Healthy Eating Index (AHEI), a scale of healthy eating that goes from zero to 80 (best score). |
| Dietary Quality, Possible Score From Zero to 80 (Best Quality Diet). | 3 months | The AHEI consists of 8 components (eg, vegetables,trans fat). Each contributed 0-10 points to the total score; a score of 10 indicates that the recommendations were fully met, whereas a score of 0 represents the least healthy dietary behavior. Intermediate intakes were scored proportionately between 0 and 10. All component scores were summed to obtain a total AHEI score ranging from zero(worst) to 80(best). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Weight From Baseline to 3 Months | 3 months | — |
| Change in Weight From Baseline to 6 Months | 6 months | — |
| Change in Calories From Baseline to 3 Months | 3 months | kilocalories |
| Change in Calories From Baseline to 6 Months | 6 months | kilocalories |
Countries
United States
Participant flow
Recruitment details
Of 78 patients responding to advertisements at UMass Medical School intranet, 36 (41%) eligible overweight and obese patients were consented to participate in the study. Dates of recruitment were May-August 2007.
Pre-assignment details
23 ineligible, 5 refused screening, 12 patients put on waiting list, 2 patients dropped prior to randomization due to pregnancy. 2 patients added from waiting list to active participation.
Participants by arm
| Arm | Count |
|---|---|
| High Fiber Diet high fiber diet (≥30 grams of total fiber per day); reduction of calories to -500 from resting metabolic rate (RMR), not less than 1200 kcal per day. | 12 |
| Low Saturated Fat low saturated fat diet (≤7% of total calories); -500 calories from RMR, not less than 1200 kcal per day. | 12 |
| Combination Diet Combination low saturated fat (≤7% of total calories);high fiber (\>30g fiber per day) -500 kcal from RMR, not less than 1200 kcal/day. | 12 |
| Total | 36 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Overall Study | Pregnancy | 0 | 1 | 1 |
| Overall Study | Withdrawal by Subject | 0 | 2 | 1 |
Baseline characteristics
| Characteristic | Low Saturated Fat | Combination Diet | High Fiber Diet | Total |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 1 Participants | 0 Participants | 0 Participants | 1 Participants |
| Age, Categorical Between 18 and 65 years | 11 Participants | 12 Participants | 12 Participants | 35 Participants |
| Age Continuous | 53.00 years STANDARD_DEVIATION 12.5 | 41.33 years STANDARD_DEVIATION 15.89 | 48.42 years STANDARD_DEVIATION 9.77 | 47.58 years STANDARD_DEVIATION 13.48 |
| Region of Enrollment United States | 12 participants | 12 participants | 12 participants | 36 participants |
| Sex: Female, Male Female | 10 Participants | 10 Participants | 11 Participants | 31 Participants |
| Sex: Female, Male Male | 2 Participants | 2 Participants | 1 Participants | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 12 | 1 / 12 | 0 / 12 |
| serious Total, serious adverse events | 0 / 12 | 0 / 12 | 0 / 12 |
Outcome results
Primary
Dietary Quality
Dietary quality was measured by the Alternative Healthy Eating Index (AHEI), a scale of healthy eating that goes from zero to 80 (best score).
Time frame: 6 mos
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Fiber Diet | Dietary Quality | 38.78 score | Standard Deviation 3.2 |
| Low Saturated Fat | Dietary Quality | 41.18 score | Standard Deviation 3.51 |
| Combination Diet | Dietary Quality | 39.76 score | Standard Deviation 3.7 |
Comparison: Mean dietary quality score by visit and study group was estimated using SAS PROC MIXED. All analyses were performed using SAS 9.13 (SAS Institute, Cary, NC, USA).p-value: 0.14Mixed Models Analysis
Primary
Dietary Quality, Possible Score From Zero to 80 (Best Quality Diet).
The AHEI consists of 8 components (eg, vegetables,trans fat). Each contributed 0-10 points to the total score; a score of 10 indicates that the recommendations were fully met, whereas a score of 0 represents the least healthy dietary behavior. Intermediate intakes were scored proportionately between 0 and 10. All component scores were summed to obtain a total AHEI score ranging from zero(worst) to 80(best).
Time frame: 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Fiber Diet | Dietary Quality, Possible Score From Zero to 80 (Best Quality Diet). | 44.90 score | Standard Deviation 3.51 |
| Low Saturated Fat | Dietary Quality, Possible Score From Zero to 80 (Best Quality Diet). | 44.90 score | Standard Deviation 3.2 |
| Combination Diet | Dietary Quality, Possible Score From Zero to 80 (Best Quality Diet). | 43.75 score | Standard Deviation 3.7 |
Secondary
Change in Calories From Baseline to 3 Months
kilocalories
Time frame: 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Fiber Diet | Change in Calories From Baseline to 3 Months | -464.05 calories | Standard Deviation 94.52 |
| Low Saturated Fat | Change in Calories From Baseline to 3 Months | -190.90 calories | Standard Deviation 103.54 |
| Combination Diet | Change in Calories From Baseline to 3 Months | -638.91 calories | Standard Deviation 109.15 |
Secondary
Change in Calories From Baseline to 6 Months
kilocalories
Time frame: 6 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Fiber Diet | Change in Calories From Baseline to 6 Months | -364.82 calories | Standard Deviation 94.52 |
| Low Saturated Fat | Change in Calories From Baseline to 6 Months | -187.19 calories | Standard Deviation 103.54 |
| Combination Diet | Change in Calories From Baseline to 6 Months | -626.32 calories | Standard Deviation 109.15 |
Secondary
Change in Weight From Baseline to 3 Months
Time frame: 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Fiber Diet | Change in Weight From Baseline to 3 Months | -7.0 pounds | Standard Deviation 2 |
| Low Saturated Fat | Change in Weight From Baseline to 3 Months | -9.1 pounds | Standard Deviation 2.2 |
| Combination Diet | Change in Weight From Baseline to 3 Months | -6.7 pounds | Standard Deviation 2.3 |
Secondary
Change in Weight From Baseline to 6 Months
Time frame: 6 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Fiber Diet | Change in Weight From Baseline to 6 Months | -9.1 pounds | Standard Deviation 2 |
| Low Saturated Fat | Change in Weight From Baseline to 6 Months | -10.2 pounds | Standard Deviation 2.2 |
| Combination Diet | Change in Weight From Baseline to 6 Months | -7.0 pounds | Standard Deviation 2.3 |