Does Texture Affect Appetite Does Texture Affect Appetite? A Study of Sensory Specific Satiety in College-Aged Males Sc space grant symbol Project Leader: Amelia Keaton

Humans Exhibit Sensory Specific Satiety Novel sensory properties of foods induce satiated subjects to eat more in a multi-course meal (Rolls,B.J. 1980) Model of overeating and weight gain Is this a possible method of increasing food consumption in astronauts who experience a loss of appetite?

Sensory Properties That Affect Food Intake in Humans Portion Size (Rolls, B.J., 2002) Palatability (Rolls, B.J. et al, 1982; Rolls, E.T., 1996) Taste Odor Appearance Texture?

Why is this important? If we can manipulate the texture of a limited number of food items, then we can possibly increase food intake in astronauts This would prove especially important for long-term space missions and lunar or planetary colonization

Hypothesis Hungry subjects fed to satiety on foods of one texture will eat more of the same foods when presented as a different texture. Due to past research on sensory properties

Methods: Meals Crackers (4 kcal/g) Water Crushed or Chunked: Pineapple (0.6 kcal/g) Cheese (3.9 kcal/g) Peanuts (5.8 kcal/g) Crushed Chunked

Experimental Timeline Subject Arrives (males age 17-22) Fasted ~12 hrs Signs Waiver Reads instructions Meal 1: T=0mins Crushed Meal Presented VAS Completed T=15mins Meal 1 ends 5min break Assigned to crush or chunk group for Meal 2 Meal 2: T=20mins Meal 2 presented (crush or chunk) VAS completed T= 35mins Meal 2 ends Subject Released Instructions: 1) Do not mix food. 2) Drink all water within 15 minute meal. 3) Eat until you’ve had enough during each meal. 4) Do not communicate with other subjects about the food. Animate-show guidelines VAS-explain or Data Collection and Analysis Consumption was measured by mass and calories after each meal One-way Repeated Measures ANOVA and post hoc Student Newman Keuls testing T-tests where appropriate

Subjects Crush/crush n= 19 Crush/chunk n= 17 p-value (t-test) Height (cm) 180.0 ±1.9 181.2 ± 1.7 0.637 Weight (kg) 80.0 ± 3.3 82.1 ± 3.7 0.676 Age (yr) 19.0 ± 0.3 19.8 ± 0.3 0.075 Body Mass Index (range) 24.3 ± 0.8 20-32 24.9 ± 0.8 0.567

Results: Meal 1

Visual Analogue Ratings: Meal 1

Meal 1 Intake (mass) Crush/chunk group consumed more food by chance-no sig. difference in individual food weights, just total

Meal 1 Intake (Calories) Pilot Study-not sure why crush/chunk group ate more

Results: Meal 2 or or

Visual Analogue Ratings: Meal 2 * ~40% * ~20%

Meal 2 Intake (mass) P value for cheese was no significant, but close (0.067). Though pineapple consumption was higher by mass in second group, the food is not energy dense and

Meal 2 Intake (calories) While more significantly more mass was not consumed by the crush/chunk group, the fact that it is more energy dense cause total caloric intake for this group to be significantly higher

Summary Subjects offered a different texture in Meal 2 consumed significantly more mass and calories than those offered the same texture Subjects offered a different texture in Meal 2 rated that meal as more appealing than those offered a second meal of the same texture

Conclusions and Applications Humans demonstrate Texture-Specific Satiety Changes in texture of some foods are sufficient to increase the amount of food consumed in a multi-course meal By changing the texture of foods, NASA scientists may be able to increase food intake for astronauts on a long-term spaceflight with limited foods available

Future Directions for Human Studies In order to increase food intake, it may be possible to manipulate the following food properties while subjects are in a head-down tilt model of microgravity: Palatability Energy density Texture

Acknowledgements We would like to thank the Bio250 and Bio 450 classes at Wofford Colllege for collecting the background data for experiments presented today

Visual Analogue Ratings: Meal 2