EAL

NNNS: Effect on Appetite and Food Intake (2011)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

The aim is to compare the effects of soft drinks containing sucrose vs. aspartame on appetite ratings and 48-hour energy and macronutrient intake of healthy females of moderate dietary restraint and also to determine how knowledge of the drink type affected these measures.
Food intake over 48 hours was studied, as energy compensation may not be detected during consumption of a single test meal and may only become evident later under ad libitum conditions.

Inclusion Criteria:

Healthy normal-weight female university students
If scores on the Three-Factor Eating Questionnaire (TFEQ) indicated dietary restraint (cognitive restraint score >10 out of a possible 21).

Exclusion Criteria:

Currently dieting
Reported, in a question added to the TFEQ, that their eating patterns were markedly affected by their menstrual cycle.

Description of Study Protocol:

Recruitment

By posters placed throughout the University of Sheffield and by word of mouth.

Design

Subjects came to the center at 9:00 a.m. on three occasions, each exactly one week apart, after they had consumed their usual breakfast. They were given a different drink type on each test day in a randomized order: Normal sucrose-containing lemonade, diet aspartame-containing lemonade and carbonated mineral water.

Blinding Used

Subjects attending the center on the same day were in the same study group to prevent the uninformed group from obtaining information about the drink type from the informed group.
Seven subjects were informed of the drink type they were consuming.
Subjects were instructed to eat until full.

Intervention

Drinks (330ml) were administered at 9:30 a.m., 11:30 a.m., 2:00 p.m. and 4:00 p.m. and were consumed within 15 minutes.
High-carbohydrate and high-fat snacks were provided for each subject between 9:30 a.m. and 12:30 p.m. and again at 1:30 p.m. and 5:30 p.m.
A self-selected cold lunch was presented between 12:30 p.m. and 1:00 p.m.
A pre-selected evening meal was served between 5:30 p.m. and 6:00 p.m. Subjects were served with the same evening meal on each of the three study days.
All foods were weighed before and after presentation in amounts in excess of that which subjects would normally eat.

Statistical Analysis

SPSS, ANCOVA and post hoc Scheffe tests.
A P-value of <0.05 was considered significant.
Dietary data analyzed by COMP-EAT dietary analysis package.

Data Collection Summary:

Timing of Measurements

Diet intake: On departure from the center, at 7:00 p.m., subjects were provided with scales and food diaries to record remainder of the evening and the following day.
Ratings of hunger, fullness and prospective food consumption: Indicated on 100mm visual analogue scale questionnaires adminstered at hourly intervals from 9:00 a.m., until 12:00 p.m. and from 1:30 p.m., onwards and five minutes prior to and every 15 minutes in the hour following the lunch-time and evening meals. Last scale administered at 7:00 p.m. In between, male subjects were free to read, work or watch television.

Description of Actual Data Sample:

Initial N: 14 female university students
Attrition (final N): No drop-outs
Age: Not reported
Ethnicity: UK
Other relevant demographics: UK
Anthropometrics: Not reported
Location: Center for Human Nutrition, UK.

Summary of Results:

Variables	ASL (g)	SSL (g)	CMW (g)
First study day
Energy (MJ)	13.3±0.9^a	11.6±0.9	12.4±0.8
Fat	168.0±11.9^a	140.1±11.6	151.6±12.8
Carbohydrate	338.6±19.1	316.7±21.7	326.7±14.2
Protein	123.4±8.3^a	105.2±8.3	115.7±7.7
Following day
Energy	8.4±0.7^a^b	6.4±0.7	6.8±0.5
Carbohydrate	254.8±21.3^ab	61.5±9.1	63.5±5.7
Two-day total
Energy	22.5±0.9^a^b	18.8±0.8	19.8±0.8
Fat	236.7±12.5^a	201.7±10.7	215.2±11.6
Carbohydrate	593.4±26.6^ab	507.8±20.0	528.7±20.3

a=Significantly different from sucrose-sweetened lemonade, P<0.05
b=Significantly different from carbonataed mineral water, P<0.05

Other Findings

Appetite ratings: Ratings of hunger, fullness and prospective consumption thoughout the first study day were no different while consuming the different drinks.
Energy intake and macronutrient selection: Energy intake from the snacks and test meals provided in the department during the first day was lower while consuming the sucrose-sweetned lemonade compared with the aspartame-sweetened lemonade (P<0.01)

When energy from the sucrose-sweetened lemonade (1,318kJ, 330kcal) was accounted for, there was no difference in overall energy intake between the three treatment groups (Figure Two). Significant decreases in the absolute amounts of fat (P<0.01) and protein (P<0.01) consumed while drinking the sucrose-sweetened lemonade compared with the aspartame-sweetened lemonade and a non-significant decrease in the amount of carbohydrates (P=0.1) consumed, but no difference in macronutrient intake, when expressed as percentage total energy intake (Table Two).

The day after consuming the aspartame-sweetened lemonade, energy intake was higher when compared with both the sucrose-sweetened lemonade (P<0.01) and water (P<0.05). Protein decreased after the aspartame-sweetened drink (P<0.05), when expressed as percentage energy consumed. Total energy (P<0.01) and absolute carbohydrate (P<0.02) intake over the two days studied was higher following the aspartame-sweetened drink, compared with the two other treatments. Absolute fat intake was higher after the aspartame-sweetened drink, compared with the sucrose-sweetened lemonade (P<0.01), but not carbonated mineral water. No differences in total macronutrient intake, when expressed as percentage of energy consumed over the two study days.

Author Conclusion:

These results suggest that in females with eating restraint, substituting sucrose-sweetened drinks for diet drinks does not reduce total energy intake and may even result in a higher intake during the subsequent day.

Limitations

Rest of diet needed to be more strictly controlled, the number of subjects may have been to small (n=7 in each group) to test with reasonable power the effect of information on intake.

Funding Source:

Industry:

Sugar Bureau

Commodity Group:

University/Hospital:

Northern General Hospital

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?	Yes
	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?		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?	???
	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?	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?	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?		No
	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?	No
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	No
	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?	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?		No
	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?	No
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	No
	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?	No
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	No
	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?	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