EAL

SSPSM: Nutrient Intake (2014)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To evaluate the clinical effects of a comprehensive pre-packaged meal plan incorporating the overall dietary guidelines of the American Diabetes Association and other national health organizations, relative to those of a self-selected diet based on the exchange lists in free-living individuals with type 2 diabetes.

Inclusion Criteria:

Women and men
Aged 25 years to 70 years
BMI of no more than 42kg/m²
Fasting glucose level greater than 7.77mmol per L
HbA1c level of no more than 200% of the median for assay (15.4%)
Provided written informed consent.

Exclusion Criteria:

Individuals with chronic life threatening diseases or a history of alcohol or drug abuse
Women who were pregnant, lactating or not practicing a medically approved method of birth control were excluded.

Description of Study Protocol:

Recruitment: Women and men aged 25 years to 70 years, who had type 2 diabetes treated with diet or an oral hypoglycemic agent were recruited through clinics and advertisements
Design: Randomized controlled trial
Blinding used: Implied with measurements.

Intervention

Subjects randomized to one of two programs for 10 weeks:
- Campbell's Center for Nutrition and Wellness (CCNW) meal program
  - Program targeted 55% to 60% carbohydrate, 15% to 20% protein and 20% to 30% fat
  - The diet plan consists of six pre-packaged breakfasts, eight lunches and 10 dinner entrees with six snack selections
  - Subjects were instructed to consume one breakfast, lunch and dinner entree, as well as one serving of fruit, vegetable and low-fat dairy products
  - One selection of alcoholic beverages or the isocaloric equivalent in fruits, vegetables or dairy products was allowed
  - The CCNW diet plan satisfied sodium, total and saturated fat, cholesterol, fiber, and carbohydrate recommendations and was supplemented with vitamin and minerals to satisfy at least 100% of the recommended adult daily allowances for all nutrients except vitamin D.
- Self-selected diet (SSD): Subjects on this plan were prescribed a fixed number of servings from each of the American Diabetes Association exchange lists.
A nutrition prescription was calculated for each subject using the Harris-Benedict equation adjusted for the individual's activity level
For all study participants, nutrition counseling was limited to a 30-minute session at Week Zero and a 15-minute session at Week Two.

Statistical Analysis

Power calculations were based on data obtained in a pilot study which involved a total of 77 subjects
The present study was designed with a power of at least 80% and a two-sided alpha of 0.05 to detect with a sample of 80 in each group between-diet differences of 0.6mmol per L in glucose, 1% in HbA1c, 0.26mmol per L in total cholesterol, 0.23mmol per L in triglycerides and three mmHg in blood pressure
Using an intent-to-treat approach, the last available measurement in the treatment period was used for subjects who did not complete the study
A two-sided probability value of 0.05 or lower was considered statistically significant, data are presented as means ±SD.

Data Collection Summary:

Timing of Measurements

During the 4 week baseline period, subjects were seen weekly for weight and blood pressure measurements.
Blood samples were collected at week -4 for fasting glucose and HbA1c measurements and at week -2 for lipoprotein determinations

Dependent Variables

Glucose, HbA1c and fructosamine were measured by SmithKline Beecham Clinical Laboratories.
Plasma lipids were determined at the Northwest Lipid Research Laboratories. Triglycerides and total cholesterol were assayed by colorimetric enzymatic analysis. HDL cholesterol was analyzed by the heparin-manganese method and LDL cholesterol was calculated by the Friedwald algorithm.
Blood pressure measurements were standardized across centers in a pre-study training session.

Independent Variables

Subjects randomized to one of two programs for 10 weeks:
- Campbell's Center for Nutrition and Wellness (CCNW) meal program: Program targeted 55-60% carbohydrate, 15-20% protein and 20-30% fat. The diet plan consists of 6 prepackaged breakfasts, 8 lunches and 10 dinner entrees with 6 snack selections. Subjects were instructed to consume one breakfast, lunch and dinner entree, as well as one serving of fruit, vegetable and low-fat dairy products. One selection of alcoholic beverages or the isocaloric equivalent in fruits, vegetables or dairy products was allowed. The CCNW diet plan satisfied sodium, total and saturated fat, cholesterol, fiber, and carbohydrate recommendations and was supplemented with vitamin and minerals to satisfy at least 100% of the recommended adult daily allowances for all nutrients except vitamin D.
- Self selected diet (SSD): Subjects on this plan were prescribed a fixed number of servings from each of the American Diabetes Association exchange lists.
A nutrition prescription was calculated for each subject using the Harris Benedict equation adjusted for the individual's activity level.
For all study participants, nutrition counseling was limited to a 30 minutes session at week 0 and 15 minute session at week 2.
Food records were completed for two nonconsecutive weekdays and one weekend day, study nutritionists reviewed food records with the subjects for completeness and detail. Food records were analyzed at the coordinating center using Nutrition Coordinating Center Database (NDS v 2.8).

Description of Actual Data Sample:

Initial N: 202 (102 women and 100 men, 100 randomized to the CCNW meal plan and 102 to the self-selected diet)
Attrition (final N): 196 subjects (four subjects from the CCNW meal plan and one subject from the SSD plan withdrew before the intervention and one subject from the CCNW meal plan withdrew during the intervention)
Age: Mean age of overall cohort was 55.5±8.9 years
Ethnicity: 11% black, 6% Asian or Pacific Islander, 83% white
Other relevant demographics: Oral diabetic medication was used by 75% of the cohort
Anthropometrics: Not described
Location: 10 medical centers in the United States and Canada.

Summary of Results:

Key Findings

Food records showed that multiple nutritional improvements were achieved with both diet plans
Energy intake on the CCNW plan was reduced from 1,917±565kcal to 1,655±357kcal per day and on the SSD plan from 2,160±706kcal to 1,679±442kcal per day
Total caloric intakes decreased significantly in both diet groups (P<0.0001). This decrease was greater (P<0.05) in the SSD (468±509kcal) than in the CCNW Group (257±558kcal).
Both diet groups reported significant increases in the percentages of calories consumed from carbohydrate (11±7.3% in the CCNW Group and 9±7.7% in the Self-Selected Diet Group, P<0.0001) and protein (2% in both groups, P<0.0001)
There were significant decreases in the percentages of calories consumed as total and saturated fat (P<0.0001 for both), with the decreases being significantly greater in the CCNW Group than in the Self-Selected Diet Group [total fat, -15±6.5% vs. -10±7.3%, respectively (P<0.0001); saturated fat, -5±2.9% vs. -4±2.9% (P<0.01)]
Both diet interventions resulted in significant improvements in cholesterol, fiber and sodium intakes (all P<0.0001). While cholesterol intakes were not significantly different between groups, the CCNW Group showed a significantly greater increase in fiber intake (12±6.9g vs. 3±6.6g, respectively; P<0.0001) and a significantly greater decrease in sodium intake (-1,016±927mg vs. -600±1,064mg; P<0.01) than the Self-Selected Diet Group.
There were significant overall reductions in body weight and BMI, fasting plasma glucose and serum insulin, fructosamine, HbA1c, total and LDL-cholesterol and blood pressure (P<0.001 or better for all)
With treatment, body weight and BMI were significantly reduced in both diet groups (P<0.0001 for both). Average weight losses were 3.4±3.1kg in the CCNW Group and 2.9±2.8kg in the SSD Group.
In general, differences in major end-points between the diet plans were not statistically significant.

Author Conclusion:

Glycemic control and cardiovascular risk factors improve in individuals with type 2 diabetes who consume diets in accordance with the American Diabetes Association guidelines
The prepared meal program was clinically effective as the exchange list.

Funding Source:

Industry:

Campbell's Soup Company for Nutrition and Wellness

Food Company:

Reviewer Comments:

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	No
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	6.6.	Were extra or unplanned treatments described?	Yes
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	Yes
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	Yes
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes