EAL

NNNS: Nutrient Quality (2006)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To observe the relationship between weight change during the year preceding enrollment and artificial sweetener use in women.

Inclusion Criteria:

Sex: All
Ages: 50 to 69 years
Education: At least a high school education
health: No history of diabetes, heart disease or cancer
Smoking: No change in preceding five years
Diet: No major change stated in the past 10 years and who were current artificial sweetner (AS) users of at least 10 years duration or who had never used AS.

Exclusion Criteria:

None noted.

Description of Study Protocol:

Recruitment

Ongoing American Cancer Society Study from 1982.

Statistical Analysis

All analyses stratified by BMI and adjusted for weight in five-year intervals.

Data Collection Summary:

Timing of Measurements

Frequency consumption: 28 items.

Description of Actual Data Sample:

Initial N: Subsample of 25,000 men and 25,000 women randomly selected from the cohort of 1.2 million subjects. Out of 685,748 women originally enrolled in the cohort, 78,694 women met these restrictions. There were 17,016 long-term AS users (21.6%) and 61,678 non-users.
Age: 50 to 69 years.

Summary of Results:

Initial Findings

Stellman, 1986: Obesity was positively correlated with AS usage. The overall proportion of AS users increased with BMI from 12.9% in the lowest quintile to 29.8% in the highest. The percentage who gained weight was significantly higher among users than among non-users at every level of initial BMI.
Among those who gained weight, the average number of pounds gained by AS users was significantly higher (by 0.5 to 1.5 pounds) than the amount gained by non-users. Among those who lost weight, the number of pounds lost differed between users and non-users only in the obese. There, AS users lost 0.7 to 1.4 pounds more than did non-users.
AS users of both sexes ate chicken, fish, green leafy vegetables, tomatoes, cabbage and other raw vegetables significantly more often than did non-users and ate beef, butter, pasta, white bread, potatoes, ice cream and chocolate significantly less often.

Mean Number of Times per Week Specific Foods Were Eaten Classified by Artificial Usage


Food	Males	Males	Females	Females
	No	Yes	No	Yes
Beef	1.8	2.7*	2.6	2.5*
Pork	1.5	1.4*	1.2	1.3*
Chicken	1.7	1.9*	1.9	2.1*
Liver	0.3	0.3	0.3	0.3
Ham	1.2	1.1*	0.9	0.9
Fish	1.4	1.5*	1.4	1.7*
Smoked meats	0.8	0.8	0.6	0.6
Frankfurters, sausage	1.2	1.2	0.9	1.0*
Butter	2.7	1.9*	2.8	1.9*
Margarine	5.1	5.0	5.2	5.2
Cheese	3.1	3.1	3.4	3.5
Eggs	2.9	2.9	2.7	2.8*
Green leafy vegetables	4.6	4.8*	4.9	5.1*
Tomatoes	3.5	3.7*	3.7	3.9*
Cabbage	1.8	2.0*	2.1	2.2*
Raw vegetables	3.3	3.4*	4.2	4.4*
Carrots	2.0	2.1*	2.3	2.4
Squash	1.7	1.7	1.8	1.8
Citrus fruits and juices	4.8	4.9*	5.2	5.3
Pasta	1.8	1.7*	1.9	1.8*
White bread	4.5	4.0*	4.1	3.8*
Brown rice or whole wheat	2.3	2.3	2.4	2.5
Bran or corn muffins	0.9	1.0*	0.9	1.0*
Potatoes	3.6	3.1*	3.2	2.8*
Oatmeal or shredded wheat	2.6	2.8*	2.6	2.7
Cold cereals	2.8	2.9	2.4	2.5*
Ice cream	2.6	2.4*	2.3	2.2*
Chocolate	1.7	1.5*	1.8	1.7*

No=never used
Yes=current user
*P<0.05

Food Frequency Results


Food Items Eaten	Males	Females
Significantly less often by AS users than by non-users	Beef, pork, ham, butter, pasta, white bread, potatoes, ice cream, chocolate	Beef, butter, pasta, white bread, potatoes, ice cream, chocolate
Significantly more often by AS users than non-users	Chicken, fish, green leafy vegetables, tomatoes, cabbage, raw vegetables, carrots, citrus fruits or juices, bran or corn muffins, oatmeal or shredded wheat	Pork, chicken, fish, frankfurters, sausage, eggs, green leafy vegetables, tomatoes, cabbage, raw vegetables, bran or corn muffins, cold cereals
Equally often by AS users and non-users	Liver, smoked meats, frankfurters, sausage, margarine, cheese, eggs, squash, brown rice or whole wheat, cold cereals	Ham, liver, smoked meats, margarine, cheese, carrots, squash, citrus fruits or juices, brown rice or whole wheat, oatmeal or shredded wheat

Author Conclusion:

Limitations

Study is observational and there is a need for a controlled trial
Short-term usage, alone or coupled with a major dietary change, may be beneficial. This was only long-term usage.
No inferences can be made of 607,054 women who did not fulfill the selective conditions for inclusion
Observations did not include serving size, total food consumption and calories, nor can the hypothesis that AS users increased their total food consumption, thereby leading them to gain more weight than non-users be proven.

Conclusion

This is an observation study and it did not include serving size, total food consumption and calories. Therefore, the hypothesis is that AS users increased their total food consumption therby leading them to gain more weight than non-users cannot be proven. Casual long-term usage of AS in the absence of other major changes in lifestyle does not by itself led to weight loss.

Funding Source:

Reviewer Comments:

Objectives and the actual paper were very difficult to follow
AS was defined as artificial sweeteners; did not specify which ones.

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)	No
	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.)	No
	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?	Yes
	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%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	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?	Yes
	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.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	Yes
	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?	N/A
	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?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	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)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	No
	8.6.	Was clinical significance as well as statistical significance reported?	No
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
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