EAL

NNNS: Weight (2006)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To investigate body weight, concerns about body weight and eating styles in habitual heavy users and non-users of artificially sweetened beverages.

Inclusion Criteria:

Individuals who consumed >825ml of artificially sweetened beverages per day are classified as habitual heavy users of artificially sweetened beverages (HAS)
Individuals who consumed >825ml of unsweetened or naturally sweetened beverages per day are classified as non-users of artificial sweeteners (NAS).

Exclusion Criteria:

All other survey respondants.

Description of Study Protocol:

Recruitment: Ad requesting volunteers for a nutrition study and a convenience sample of staff and students at the University of Leeds (October 1996 to March 1997)
Design: Questionnaire distributed to 250 individuals who responded to the ad requesting volunteers, as well as the convience sample of 450 staff and students.
Statistical analysis: 2x2 MANOVA and binary logistic regression.

Data Collection Summary:

Timing of Measurements

Single questionnaire.

Dependent Variables

BMI: Calculated from self-reported height and weight
Body weight concerns: Were measured using the DEBQ Restrained Eating scale (van Strien et al, 1986), the YEPQ Dieting scale (Kristeller, Rodin, 1989) and the EDI Drive for Thinness scale and Body Dissatisfaction scale (Garner, Olmstead, 1984). These scales assess eating patterns directly related to body weight.
Eating style: Measured using the Dutch Eating Behavior Questionnaire Emotional Eating scale and External Eating scale (van Strienet al, 1986), the Yale Eating Patterns Questionnaire (YEPQ) Uninhibited scale, Oversnacking scale, Bingeing scale, Satiation scales (full, nausea and guilty), Attribute scales (physical and emotion) (Kristeller, Rodin, 1989) and the Eating Disorder Inventory Bulimia scale and Personality Characteristics scales (Garner, Olmstead, 1984). These scales represent a variety of eating patterns not directly related to body weight or concerns about body weight.

Independent Variables

Heavy consumption of artificially sweetened beverages
Gender: Authors report no differences between genders and no strong evidence for a user-group by-gender interaction, therefore differences between groups were examined using univariate functions.

Description of Actual Data Sample:

Initial N

248 of the 700 (35.4%) questionnaires were returned completed, of those 120 were used in the study (48.4% of the responses).
128 were not used as they were neither heavy-users nor non-users of artificial sweeteners.
51 (10 males and 41 females) were habitual heavy users of artificially sweetened beverages (HAS) who consumed >825ml of artificially sweetened beverages per day
69 (21 males and 48 females) were non-users of artificial sweeteners (NAS) who consumed >825ml of unsweetened or naturally sweetened beverages per day.

Attrition (Final N)

There was no attrition: Final N=120.

Age

Mean age: 25.1 years (SD=8.0 years).

Ethnicity

Not stated.

Other Relevant Demographics

The majority of the participants were university students.

Location

Leeds, UK.

Summary of Results:

HAS reported significantly higher scores than NAS on the following measures:

BMI: [F(1,75).15.10, P<0.001]
DEBQ Restrained Eating: [F(1,75).28.21, P<0.001]
EDI Drive for Thinness: [F(1,75).23.57, P<0.001]
YEPQ Dieting: [F(1,75).16.07, P<0.001]
EDI Body Dissatisfaction: [F(1,75).19.00, P<0.001]
YEPQ Satiation-Guilt: [F(1,75).10.27, P=0.002]
YEPQ Attribute-Physical: [F(1,75).5.33, P=0.02].

No differences between user groups were found in the other scales: Largest F(1,75).2.26, P=0.14. The following table contains data for all scales:

Measure		Users
Measure		HAS Mean (SD)	NAS Mean (SD)
Body weight	BMI	25.7 (4.5)*	22.4 (2.4)
Body weight concerns	DEBQ-Restrained Eating	30.1 (9.5)*	19.5 (7.4)
	YEPQ-Dieting	6.1 (13.3)*	4.4 (16.6)
	EDI-Drive for Thinness	6.6 (6.5)*	0.9 (2.4)
	EDI-Body Dissatisfaction	14.5 (9.3)*	5.6 (6.0)
	Eating style DEBQ ± Emotional Eating	33.8 (12.3)	29.6 (9.9)
	DEBQ-External Eating	31.9 (5.9)	31.7 (4.5)
	YEPQ-Uninhibited Eating	5.6 (3.2)	6.2 (3.4)
	YEPQ-Oversnacking	7.6 (4.5)	5.8 (3.5)
	YEPQ-Bingeing	8.5 (4.8)	7.5 (4.6)
	YEPQ-Satiation ± Full	10.4 (2.8)	10.2 (3.0)
	YEPQ-Satiation ± Nausea	15.0 (6.1)	14.7 (6.4)
	YEPQ-Satiation ± Guilt	8.7 (4.6)*	5.0 (3.4)
	YEPQ-Attribute ±Physical	21.4 (3.6)*	19.3 (3.5)
	YEPQ-Attribute ± Emotion	3.5 (1.8)	3.5 (1.4)
	EDI-Bulimia	0.8 (2.2)	1.9 (3.4)
	EDI-Personality	15.7 (11.1)	14.7 (12.0)

The table below contains B, SE and P-value of all measures in the regression equation and scores and P-value of all measures not in the regression equation (N=95)

_	B	SE	P
In regression equation
BMI	0.254	0.093	0.01
YEPQ-Dieting	0.278	0.131	0.03
EDI-Drive for Thinness	0.214	0.081	0.01
Not in regression equation
DEBQ-Restrained Eating		0.975	0.32
EDI-Body Dissatisfaction		0.040	0.84
DEBQ-Emotional Eating		1.633	0.20
DEBQ-External Eating		2.457	0.12
YEPQ-Uninhibited Eating		0.004	0.95
YEPQ-Oversnacking		0.106	0.74
YEPQ-Bingeing		1.300	0.25
YEPQ-Satiation-Full		0.182	0.67
YEPQ-Satiation-Nausea		0.471	0.49
YEPQ-Satiation-Guilt		0.041	0.84
YEPQ-Attribute-Physical		1.435	0.23
YEPQ-Attribute-Emotion		0.834	0.36
EDI-Bulimia		2.559	0.11
EDI-Personality		0.069	0.79

Author Conclusion:

Habitual heavy users reported higher body weights (BMI), greater concerns about weight and greater tendencies toward certain eating styles when compared to non-users. Using logistic regression, 82% of respondents were correctly classified as heavy- or non-users of ASBs, using body mass index and body-weight concerns.

Funding Source:

University/Hospital:

School of Psychology University of Leeds (UK)

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?		No
	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?	No
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	No
	2.4.	Were the subjects/patients a representative sample of the relevant population?	No
3.	Were study groups comparable?		N/A
	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?	???
	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?	N/A
	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?	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?		???
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	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?	???
	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?	Yes
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	N/A
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	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?	N/A
	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?	N/A
	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)?	Yes
	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?		No
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
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