NNNS: Appetite (2006)
Rolls BJ, Laster LJ, Summerfelt A. Hunger and food intake following consumption of low-calorie foods. Appetite. 1989 Oct; 13 (2): 115-27.
The present study was designed to test the effects of consumption of two commercially available dessert products (Jell-O and pudding) sweetened with either aspartame or sucrose on hunger and food intake over the two hours after eating.
Healthy non-smokers who had no diet or health-related food restrictions or allergies and who were not on any medication or taking any drugs.
Subjects all were low-dietary restraint, less 10, by the eating inventory and within the normal range of weight and height (Metropolitan Life Insurance Company, 1959)
No history of eating disorders, as defined by a score of less than 15 on the Eating Attitudes Test and low scores on the General Health Questionnaire, signifying they were not depressed.
- Prior to entering the study, volunteers sampled the test foods at 50mm or above on a 100mm visual analog scale.
After passing screening procedures, subjects were randomly assigned to the uninformed or informed group.
Informed group: When presented with each test meal, the group was told the number of calories per half-cup serving of that food and was told the food was either high-calorie or low-calorie.
- Uninformed: Given the test meal and told that it was chocolate pudding or strawberry banana Jell-O.
- Test foods.
High-Calorie Pudding (1.6kcal/g)
- 672mg sucrose per gram of product (mean intake of sucrose was 47.8g by the informed subjects and 43.0g by the uninformed subjects).
Low-Calorie Pudding (1.0kcal/g)
- 11.55mg aspartame per gram of product (mean aspartame intake of aspartame was 391mg by informed and 290mg by uninformed subjects)
- Both pre-weighed package mixes were prepared with 24 fluid ounces of whole milk.
High Calorie Jell-O (0.6kcal/g)
- 883mg sucrose per gram of product (mean intake of sucrose was 45.2g by the informed and 41.9g by the uninformed).
Low Calorie Jell-O (0.1kcal/g)
- 35mg aspartame per gram of product (mean intake of aspartame was 254mg for the informed and 211mg by the uninformed subjects).
- Subjects were given 550mg of each food in a large bowl and all were instructed to eat as much as they wanted.
- Mixed design of analysis of variance was used to assess the effects of information status (informed, uninformed) and pre-load calorie level (low, high) on intake and visual analog scale ratings of hunger and satiety. Time within session was included in analyses rating scale data.
- Intake analyses were done on calories and grams consumed in the pre-load (test meal), the self-selection meal and combined pre-load and self-selection meal.
Timing of Measurements
- Subjects came to the laboratory at their usual lunch time once a week.
- Keep exercise and meals eaten prior to each session consistent.
- Choose a low-fat standard breakfast to eat at the same time (about three to four hours) before each session
- Not to eat or drink anything between breakfast and the beginning of each session.
- Asked to cancel and reschedule if unable to comply
- This procedure kept hunger levels within 15% of baseline for each individual
- Weight and height was recorded
- Signed consent form, approved by Johns Hopkins Human Subject Committee, which explained that the purpose of the experiment was to investigate the different types of foods on hunger and satiety, with no mention of caloric manipulation
- Familiarized with private test cubicles and given instructions about the procedures to be followed and how to use the visual analog scales to record subjective responses.
Visual Analog Scales
- Subjective ratings of the pleasantness of the taste of foods were assessed before and after consuming test meals in order to determine the effects of energy density on sensory-specific satiety or the changing hedonic response to foods.
- Trays with nine foods. Asked to rate pleasantness of foods just before the test meal, two minutes, 20, 40, 60 and 120 minutes after the test meal and two minutes after the self-selection meal.
- Samples were always presented in the following order: Tuna and mayonnaise, cheese on cracker, banana chip, chocolate pudding, turkey breast, strawberry or banana Jell-O, corn chip, fresh strawberry and chocolate bar. Along with the tray, subjects were given visual analogue scales: Assess hunger, fullness, desire to eat and prospective hunger (the amount subjects would like to eat).
After Testing and Rating Foods on First Tray
- Subjects were given a 550g test meal of pudding or Jell-O and 550g of water and allowed 15 minutes to eat. The order of the test meals was counterbalanced.
- Subjects were not allowed to read or write during meals
- When finished eating, experimenter started a timer and rating trays were given. After the 120-minute ratings, subjects were offered a self-selection meal consisting of:
- 50g banana chips
- 50g corn chips
- 150g turkey breast
- 150g tuna and mayonnaise
- 100g cheese
- 52g crackers
- 110g whole wheat bread
- 200g chocolate pudding (1.3kcal/g)
- 200g strawberry/banana Jell-O (0.35kcal/g)
- 122g chocolate bar
- 25g mayonnaise
- 20g corn margarine
- 390g cola
- 390g diet cola.
- Subjects were instructed to eat whatever they liked up to 20 minutes for the meal
- All foods and drinks were weighed before and after presentation. Energy intakes were calculated by using information obtained either directly from the product package or from food tables.
- Final test day: Uninformed subjects were called back for a blind taste test both of high- and low-energy density versions of the test foods to determine whether there were any significant differences in the pleasantness of the taste or in perceived energy density.
- Subjects were given a tray with small samples of seven foods, four of which were both versions of the Jell-O and pudding. Using visual analog scales, they assessed the pleasantness of the taste of the food, the caloric content and sweetness for the food and how fattening they thought the food was.
- Initial N: 16 males, 16 females
- Age: 18 to 35 years.
- Self-selection meal: Men ate significantly more kcals than women in both the pudding condition (P<0.03) and the Jell-O condition (P<0.02).
- Analyses of variance, combined with sex and informed or uninformed status, showed subjects consumed significantly fewer calories of the low-calorie pudding (P<0.001) than of the high-calorie pudding and of the low-calorie Jell-O (P<0.001) than of the high-calorie Jell-O.
- A non-significant trend developed (P<0.07) for all subjects to consume more calories in the self-selection meal after the low-calorie pudding, so that total intakes (test meal plus self-selection) in the low- and high-calorie conditions did not differ significantly.
- Low- and high-calorie Jell-O conditions showed no significant difference in calories consumed in the self-selection meal (P<0.23), but total intakes were not significantly different
- There was no effect of the type of food or the amount of sweetener in the test meal on the proportion of macronutrients eaten in the self-selection meal
- Over the two-hour period following the test meal, subjects were given rating trays. No significant differences were found between male and female, therefore data was combined. Low- and high-calorie versions of the test foods equally suppressed ratings of hunger, the desire to eat, the amount wanted to eat and the change in the pleasantness of the food eaten equally in both Jell-O and pudding and equally increased stomach fullness.
|Test Meal||Self-Selection Meal||Total|
|Informed Subjects (kcal)|
|Uninformed Subjects (kcal)|
|Informed Subjects (g)|
|Uninformed Subjects (g)|
- Non-significant differences exist between the visual analog scale ratings of headache, alertness, tiredness and tenseness after either caloric version of the two test meals
- Post-experiment taste test: Subjects were not able to distinguish between the low- and high-calorie versions of the pudding or Jell-O.
These results suggest that during and for a least two hours after consumption, aspartame-sweetened foods can be of benefit in reducing hunger and increasing satiety
Limitations and biases not discussed.
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?||Yes|
|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?||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?||No|
|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)?||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?||Yes|
|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|