NNNS: Effect on Appetite and Food Intake (2011)
Citation:Drewnowski A et al. Comparing the effects of aspartame and sucrose on motivational ratings, taste preferences, and energy intakes in humans. Am J Clin Nutr. 1994; 59:338-45.
Randomized Controlled Trial
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- Does the substitution of aspartame for sucrose in reduced energy foods lead to subsequent energy compensation or even energy rebound over a period of several hours as opposed to 60 minutes?
- Does the addition of aspartame to plain foods lead to stimulatin of appetite and increased energy intake that extends beyond the first test meal?
- Does replacing sucrose with aspartame, while keeping both energy and sweetness constant have an inhibitory effect on energy intake that may be due to the post-ingestive action of aspartame?
- Is there any consistency between taste-preference profiles, motivational ratings and energy intakes as measured in the same subjects over a period of several hours and under the same experimental conditions?
- In good health and not on medication
- Non-dieters and non-smokers
- Reported weight was stable, they had not gained or lost weight during the previous year and were not losing weight at the time of the study.
- Failure to meet inclusion criteria.
Description of Study Protocol:
- Recruitment: Advertising at the University of Paris VI and at the Bichat Hospital. Study approved by review boards at the University of Michigan, the French National Institute for Medical Research and Bichat Hospital. Signed consent forms.
- Design: Study followed a within-subject design, with each subject taking part in four pre-load conditions. The four sessions were scheduled on the same weekday for four consecutive weeks. Four pre-loads, composed of creamy white cheese: Plain or sweetened with aspartame, aspartame-maltodextrin or sucrose. Their energy value was either 1,255 or 2,929kJ (300 or 700kcal). Subjects arrived in the laboratory at 9:00 a.m. after an overnight fast. After being weighed, they took motivational tests and were given breakfast at 9:30 a.m. Buffet-style lunch at 12:30 p.m., snack at 4:00 p.m. and dinner at 7:00 p.m. Subjects left at 9:30 p.m.
- Blinding used: Subjects were assigned to conditions in order of their arrival in the laboratory on their first day of testing.
- Statistical Analysis: BMDP analysis of variance ANOVA for repeated measures. Tests of significance for differences between means were based on paired T-tests.
Data Collection Summary:
Timing of Measurements
- Weight: When subjects arrived at the laboratory at 9:00 a.m.
- Taste preferences: Measured before and 150 minutes after breakfast.
- Motivational ratings: Obtained at 30-minute intervals
- Food intake: Three buffet meals (lunch, snack and dinner) each consisted of the same arrangement of the same 21 foods, which were presented at each meal throughout the study.
- Motivation to eat: Measures of hunger, satiey and desire to eat were obtained by using the nine-point category scales anchored to each extreme with the statements "not at all" and "extremely." Procedure validated in previous research.
Description of Actual Data Sample:
- Initial N: 12 men and 12 women
- Attrition (final N): 12 men and 12 women
- Age: 21-36
- Anthropometrics: BMI values ranged from 19.0 to 25.1
- Location: Paris.
Summary of Results:
- Motivation to eat: Hunger ratings were influenced by the energy content of the breakfast pre-loads, though not by sweetness. Higher hunger ratings were obtained after the consumption of low-energy palin and aspartame-sweetened pre-loads (1,255kJ or 300kcal) than after sucrose and aspartme-maltodextrin pre-load.
- Taste preference profiles: Taste preference ratings at 12:00 p.m., were lower than taste preferences measured at 9:00 a.m., after an overnight fast (P<0.01). The interaction between breakfast consumption and stimulus sweetness was significant (P<0.05).
- Energy intakes per meal: Subjects who consumed less energy at breakfast consumed more during lunch. Energy intakes at lunch were significantly higher after prior consumption of 300kcal aspartame-sweetened pre-load, as opposed to 700kcal sucrose-sweetened pre-load (P<0.05) and 700 kcal aspartame-maltodextrin pre-load. Subjects who consumed 400kcal less at breakfast consumed, on average, 111kcal more at lunch. No differences in motivational ratings or in energy intakes were obtained at subsequent meals as a function of pre-load.
- Daily energy intakes: Daily energy intakes other than breakfast were not influenced by pre-load type.
Aspartame-sweetened pre-loads consumed under laboratory conditions did not promote hunger or increase food consumption in non-dieting normal-weight humans.
- Inclusion of the taste test
- Wide variety of foods available at the three meals
- Insufficient time span allowed for data collection.
|University/Hospital:||University of Michigan,Unviersite de Paris VI, INSERM, Bichat Hospital (Paris)|
No dietary records during the week when not at the laboratory.
Quality Criteria Checklist: Primary Research
|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|
|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%.)||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.)||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?||No|
|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?||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?||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?||Yes|
|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?||N/A|
|10.1.||Were sources of funding and investigators' affiliations described?||Yes|
|10.2.||Was the study free from apparent conflict of interest?||Yes|