Eating behaviours

1. Eating behaviours Week 11.1

2. What constitute ‘eating behaviours’? • How much we eat • What we eat • Who we eat with • When we eat

3. Q: Why are people overweight? • Government subsidies to agriculture  changes market prices of food (esp. meat vs. vegetables) • Option to “upsize” one’s meal • Lifestyle factors: Cars, elevators, computers, etc. • Genetics • Pregnancy • People overeat, consuming more than necessary to sustain metabolism

4. Over- vs. under-eating • Under-eating is an economic, political, and social problem; it is not a psychological problem • This is because people usually don’t under-eat, unless there are underlying clinical issues (e.g., anorexia) • Overeating (over-nutrition) is an economic, political, social, and psychological problem

5. Caveat • I’m not going to cover eating disorders. • This is about normal people – you and I.

6. Why do people overeat? • We eat mindlessly. • Our ‘environment’ supports mindless eating • But what is this ‘environment’? • Let’s find out.

7. Why do you stop eating? List some reasons why you would stop eating • No more food on plate • Everyone left (eating as social activity) • Closing time • You’re full • You are sick of eating too much of the same stuff

8. Stopping cues • What if we had stopping cues – cues that remind us to stop eating? • A timer? • A visual cue?

9. The red potato chip experiment • Pringles potato chip was an excellent way to test the “stopping cue” hypothesis. • Researchers dyed every 7th or 14th potato chip red, or did not dye any.

10. Superbowl chicken wings experiment Cues that tell you how much you have already eaten • Diners watched Superbowl. Chicken wings were served free. • Who ate more – and why? • How can you apply this to alcohol behaviour? Bones were collected periodically Bones were not collected -28% (two chicken wings fewer) Wansink & Payne (2007). Counting bones: Environmental cues that decrease food intake. Percpt Mot Skills.

11. How would you know if you are full? • Seems like a trivial question, but it’s an important question • Your stomach is not like a gas tank; there is no visual indicator when you’re full • It is via a combination interoceptionand blood sugar levels • It takes about 20 mins before food changes blood sugar levels • This means your perception of ‘fullness’ is susceptible to environmental influences, especially within the 20 mins.

12. Auto-refill (aka. bottomless bowls) • https://www.youtube.com/watch?v=gMv_-YmAlNM Wansink et al. (2005). Bottomless bowls: Why visual cues of portion size may influence intake. Obesity Res.

13. Plate size

14. Ebbinghaus illusion

15. Ebbinghaus illusion

16. Bowl size Wansink & Cheney (2005). Super bowls: Serving bowl size and food consumption. J American Med Assoc.

17. Placement First counter Salads, fruit and vegetable servings Last counter Salads, fruit and vegetable servings Which counter would people take more greens?

18. Variety • People eat more when there is variety • Sensory habituation – every new taste ‘renews’ your tastebuds

19. Saliency Secretary & chocolates study • A jar with lid of chocolates was placed on the desk of secretaries. The jar was either made of transparent glass, or opaque glass. • Guess which group of secretaries ate more chocolates? • We eat because food is available Wansink et al. (2006). Proximity’s influence on estimated and actual candy consumption. Int J Obesity.

20. Scripts • From cognitive psychology, you learnt about event-related schemas • E.g., your morning routine, bathroom routine, etc. • You also have eating routines, e.g., appetizer, main course, dessert. • Schemas can be triggered by cues • IF exam + stress, THEN popcorn

21. Who’s eating with you? DeCastro(1994). Family and friends produce greater social facilitation of food intake than other companions. Physio & Beh.

22. Birds of a feather eat together • Couples and families tend to be similar in size • Part of it could be genetics. But the social aspects of eating is important too. • For example, the frequency, quantity, and time spent eating puts pressure on someone who is trying to lose weight • Weight can be inherited, but it can also be “contagious” (≈ behavioural contagion).

23. The threat of TV • Eating while watching TV blunts your taste • You pay less attention to how much you eat • You also eat more, you eat longer • Popcorn: If you watch an hour of TV, you eat 28% more popcorn (but also 11% more carrots). Van der Waal & Dillen (2013). Leaving a flat taste in your mouth. Task load reduces taste perception. Psychological Science

24. But it’s not just TV • Radio + eating: +15% food consumed • Newspaper + eating: [don’t know yet] • Bottomline: Anything that distracts you makes you lose track of how much you already ate.

25. When do you eat? • Most people have predictable meal hours; you eat when it is time to eat. • What if time was accelerated (or slowed down) with a rigged clock? • Would your body be fooled? • Yes, for obese individuals: They ate more if they thought they ate late. Schacter (1968). Manipulated time and eating behaviour. J PersSoc Psychol.

26. Discussion (10 mins, if we have time) • Form groups of 2-3. Devise an experiment to investigate whether music affect eating behaviours. • In your design, note that there are many ways “music” and “eating behaviours” can be operationalized. • You cannot investigate music & emotions. Other than that, you are free to decide how you want to operationalize it, as long as it answers the question. Milliman (1986). The influence of background music on the behaviour of restaurant patrons. J Consumer Res .

27. Music and purchasing • German music played  Sales of German wine increased • French music played  French wine sales increased • Are humans rational?

28. Tempo of music and eating speed • Fast music: eat faster, eat more, but spend less • Slow music: eat slower (45 vs. 56 mins), drink more, spend more on drinks ($30 vs $21) → + 41% drinks revenue • Ever wonder why are fast food restaurants have bright lights, hard tables, etc. whereas high-end restaurants are dark, have velvet table cloth? http://edition.cnn.com/2010/LIVING/04/30/noisy.restaurant.business/

29. Cleaning up after eating • Problematic behavior: People don’t clean up after eating Holland et al. (2005). Smells like clean spirit. Psychol Sci.

30. Food presentation • “Here’s your free brownie”, presented either on a white china, paper plate, or napkin • That’s $9000 extra annual revenue serving the same product!

31. Menu wording +27% sales Menu A Menu B Traditional Cajun Red Beans with Rice Succulent Italian Seafood Filet Tender Grilled Chicken Home-Style Chicken Parmesan Satin Chocolate Pudding Grandma’s Zucchini Cookies • Red beans with rice • Seafood filet • Grilled chicken • Chicken parmesan • Chocolate pudding • Zucchini cookies “tastes fantastic”

32. Suppose you want to propose to your girlfriend. Would you choose… Menu A Menu B Cavier Kiwi fruit Escargots Foie Gras Snapper Calamari • Fish eggs • Chinese Gooseberry • Snails • Duck Liver • Muttonfish • Squid

33. How about encouraging healthier food options by rewording the menu? Menu A Menu B – come up with the tastiest-sounding description! ____________________ ____________________ ____________________ ____________________ • Salads

34. The broader picture

35. Some critical questions • Is regulation effective? • Do people pay attention to nutritional labels? • Do people understand nutritional labels? • Do people understand the implications of nutritional labels? • Do people have the capacity to process info? • What if we make unhealthy food more expensive, like to soda tax in UK? • Will people switch to cheaper but still unhealthy alternatives? • Will it penalize the poor? • Won’t it better to change the desires? • How can we design the eating environment to encourage healthier food options?

36. The bigger picture • This seminar is about food. • But it can be about any repetitive consumption too. • Can you extend principles from food to other domains?

37. Take home messages • Most people think we eat food that are nice, we stop when we are full, we eat when we are hungry, etc. • Sometimes we eat simply because we can. • Many cues influence our eating behavioursnonconsciously

38. “The best diet is the one which you don’t know you are on” Engineering your eating environment