Does Texture Affect Appetite? A Study of Sensory Specific Satiety in College-Aged Males 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.

Methods: Meals Water (~275 mL) Unsalted Crackers (4 kcal/g) Crushed or Chunked: –Pineapple (0.6 kcal/g) –Cheese (3.9 kcal/g) –Peanuts (5.8 kcal/g) Chunked Crushed

Experimental Timeline Subject Arrives (males age 17-22) Fasted ~12 hrs Signs Waiver Reads instructions 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. Meal 1: T=0mins Crushed Meal Presented VAS Completed Data Collection and Analysis Consumption was measured by mass and calories after each meal One-way ANOVA and post hoc Student Newman Keuls testing t-tests where appropriate or

Subjects Crush/crush n= 19 Crush/chunk n= 17 p-value (t-test) Height (cm) ± ± Weight (kg) 80.0 ± ± Age (yr) 19.0 ± ± Body Mass Index (range) 24.3 ± ±

or

* ~40% * ~60%

p=0.067

2X

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.

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. Since taste and smell are attenuated in space, manipulations of texture may be especially effective in promoting food intake. Conclusions and Applications

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 research classes at Wofford College for collecting the preliminary data for experiments presented today