• Non-smoking
• Non-dieting
• Normal weight for height (between 90% and 110% of ideal body weight), according to the Metropolitan Life Weight Tables
• No food allergies or restrictions nor any medication
• Screened using the Stunkard Eating Inventory (which measures cognitive restraint), the Eating Attitudes Test and the Zung Self-Rating Questionnaire (which measures depression)
• Score of less than 10 on the Eating Inventory Test, less than 15 on the Eating Attitudes Test, less than 50 on the Zung questionnaire
  
• Volunteer was required to complete a trial session in which he would rate pleasantness of foods and whether he would eat the foods (only subjects' ratings of 50 on 100mm visual analog scales were included in the experiment).

• All three experiments utilized a within-subjects repeated-measures design, with each subject serving as his own control
• Every subject received each of the following drinks:
• Eight ounces of sucrose-sweetened lemonade
• 16oz sucrose-sweetened lemonade
• Eight ounces of aspartame-sweetened lemonade
• Eight ounces of water
• 16oz water
• On one occasion, no drink was given.
• Each subject was run once in each of the seven conditions and the order of presentation was counter-balanced across subjects
• Subjects came to the laboratory at the same time for each of the seven sessions, with at least three days between sessions
• Subjects were asked to list, upon arrival, all the foods consumed at dinner the night before the session and at breakfast the morning of the session. These food diaries were used to monitor subjects' compliance, since they had been instructed to eat a normal dinner the night before and to eat the same breakfast on the mornings of all the session days.
• After the final session, all subjects were given a discharge questionnaire to answer.

• At 12:00 p.m., subjects arrived at the laboratory at their usual time for each of the seven sessions.
• Upon arrival, subjects completed their initial appetite ratings, which served as the baseline rating
• Received their self-selection lunch meal along with the test drink or no drink and were instructed to eat as much as they wanted and told if they wanted more to ask for it.
• Instructed to consume all of the drink during the meal and given a maximum of 20 min to eat.
• A second set of appetite ratings were done after subjects had eaten as much as they wanted.
• A third set of ratings was done after subjects had spent an hour sitting quietly in their cubicles.

• Subjects arrived at the laboratory 30 minutes before their usual lunch times
• Upon arrival, subjects completed their initial appetite ratings.
• Subjects received lemonade or water and were instructed to consume all of the drink
• Subjects were given five minutes for eight ounce drinks and 10 minutes for 16oz drinks
• In the no-load condition, subjects, after their ratings, did not receive a drink or were told to sit in their cubicles for five minutes.
• A second set of appetite ratings was done after the subjects had finished their drink and were asked to sit in their cubicles for 30 minutes
• Subjects then rated hunger and thirst for a third time and then were served lunch.
• Subjects were given same instructions as in Experiment One for lunch and were allowed 20 minutes to eat
• Subjects rated hunger, thirst, etc., immediately and then one hour after lunch.

• Subjects arrived at the laboratory 60 minutes before their usual lunch times
• Upon arrival, subjects completed their initial hunger, thirst, fullness and other sensations
• Subjects received lemonade, water or no drink and were instructed to consume all of the drink
• A second set of appetite ratings was done after subjects finished their drink and had been asked to sit in their cubicles for 30 minutes
• Subjects then rated appetite for a third time, then waited 30 minutes and completed a fourth set of ratings.
• One hour after coming to the laboratory, subjects were given a self-selection lunch and were instructed to eat as much as they wanted
• Subjects were allowed 20 minutes to eat as much as they wanted.
• Subjects rated appetite immediately following and then one hour after lunch.
  

• Subjects were naive as to the sweetener manipulation in the study.

• Energy intake including and not including the calories from the lemonade was analyzed using two-way analysis of variance with repeated-measures (BMDP software) to determine if there were any significant differences among conditions
• Post hoc Tukey’s HSD test was done when any significant main effects were observed to ascertain which means differed significantly
• Macronutrient selection in the different conditions was done by comparing the percentages of the total macronutrients consumed (by weight) derived from fat, carbohydrates or protein, across conditions using two-way analysis of variance
• Appetite rating changes (hunger, thirst, fullness, desire to eat, desire to drink, prospective drinking) were analyzed using two-way three-factor analysis of variance condition (type of load), dose (eight or 16oz) and time as factors
• Pearson’s product moment tests were used in all three experiments to determine the degree of correlation (from baseline to immediately after lunch) during each condition
• The Greenhouse-Geisser probability value is given instead of the tail probability value, whenever statistically significant, so that Type I errors often associated with repeated measures of analysis may be minimized.

Timing of Measurements

• Visual analog scales: Rated their hunger, thirst, fullness, desire to eat, desire to drink, how much they thought they could eat and how much they thought they could drink at specific times throughout the sessions by marking their responses on 100mm visual analog scales. Each subject’s baseline appetite ratings were checked at the beginning of each session to ensure that the ratings deviated no more than ±15mm across all sessions.
• Food and macronutrients: The test drink was a lemonade made with chilled water (7ºC) and freshly squeezed lemon juice sweetened to equal intensity with either sucrose or aspartame (a ratio of 200g of sucrose for every gram of aspartame was used to match sweetness). The sweetener concentrations were comparable to the amounts found in commercially available soft drinks.

• Initial sample: 42 healthy males
• Age: 21 to 39 years; mean age 25.0, SD=4.3
• Anthropometrics: 9.7%, SD=0.3% of the Metropolitan Life Weight Tables.

Results, Experiment One

• Analysis of variance comparing energy intake during the self-selection meal across all seven conditions, without including lemonade calories, produced no statistically significant differences
• Energy intake was not affected by subjects being deprived of a drink when eating their meal. Interestingly, when lemonade calories were added to the calories consumed during lunch, a two-factor two-way analysis of variance test comparing intake associated with the drink conditions showed a significant main effect for condition, P<0.01. Post hoc comparison of the means indicated that subjects consumed significantly more calories with the sucrose-sweetened lemonades than with the aspartame-sweetened lemonades or water P<0.01.    

• No significant differences were found in fat, carbohydrate and protein consumption, when intake was compared across conditions.

• Analysis of variance of the difference scores for hunger, fullness, desire to eat and prospective consumption ratings (after lunch minus the baseline rating and one hour after lunch minus the baseline) sowed the main effect of condition to be non-significant
• The difference scores for hunger exhibited a trend for dose, while prospective consumption ratings were significant for dose (P<0.05). These ratings decreased more following the 16oz drinks than following the eight-ounce drinks.
• The main effect for time was significant for hunger and fullness. There was a significant interaction between dose and time for hunger ratings, due to lower ratings immediately after lunch in the 16oz conditions (sucrose, aspartame and water) than in the eight-ounce conditions (P<0.004).
• The change in hunger from before to after lunch and total intake (lunch plus drink) during lunch found only the intake in the eight-ouncec water condition to be significantly correlated to the change in hunger. 

• There was a strong effect of dose, with the 16oz drinks decreasing thirst significantly more than the eight-ounce drinks and of time.
• Subjects were significantly less thirsty after having a drink than after not having a drink, except in the eight-ounce sucrose condition (P<0.008).

• Food intake in the no-load condition was not different from the drink conditions, even though the thirst ratings (except in the eight-ounce sucrose condition) were significantly different
• No significant correlation was found between thirst changes and food intake during lunch.

Triangle test

• Only 5 of the 14 subjects chose the correct pair of samples in their first trial. In the second trial 9 of the 14 subjects chose correctly.

• The results indicate that in non-dieting males, asparatame in concentrations similar to those in commercially available drinks did not increase hunger ratings or food intake
• Caloric drinks taken with lunch increased total energy intake in that meal
• Sucrose-sweetened drinks may decrease thirst less than water or aspartame-sweetened drinks, when taken with a meal.