ESPEN Congress Copenhagen 2016

Transcription

1 ESPEN Congress Copenhagen 2016 TASTE PREFERENCES AND PALATABILITY DEVELOPING TASTE PREFERENCES P. Møller (DK)

2 Developing taste preferences Per Møller University of Copenhagen

3 Learning objectives Where do taste preferences come from? How do taste preferences change?

4 Taste and eating behaviour: why? Sensory properties most important determinant of food choice strongly connected to some (maybe all?) satiety mechanisms determine via implicit learning our habits (not sweet, fat, bitter...) man is an omnivore...

5 Many senses important for perception and appreciation of foods Flavour: the integration of signals from these 4 senses as foods are eaten taste smell touch (tactile) trigeminality (pungency, irritation) Indirect effects on flavour from other senses vision,audition,temperature..

6 From Shepherd G, Smell images and the flavour system in the human brain. Nature, vol 444, , 2006

7 Where do preferences come from? Very few hard-wired from birth sweet fat bitter importance of incidental learning and implicit memory

8 How/why do preferences change? Conditional learning(pavlov s dogs) - flavour-flavour learning - flavour-nutrient learning - repeated exposure...and other mechanisms, e.g. - Exposure with stimuli more complex than those corresponding to optimal preference optimal præference p.t. - social imitation

9 Benoist Schaal et al: Human foetuses learn odours from their pregnant mother s diet From Schaal B et al Chem. Senses 25: (2000)

10 Lactating mothers:transfer of flavour after ingestion Time after ingestion (h) From Hausner H et al Physiology & Behavior 95: (2008)

11 Flavour exposure during lactation - Mother eats carrot -> baby develops a preference for carrot flavour - Mother eats garlic -> baby develops a preference for garlic flavour and many other examples cf. Forestel CA et al. The Ontogeny of Taste Perception and Preference Throughout Childhood, Ch.36 in Handbook of Olfaction and Gustation, ed. Doty RL, Wiley 2015.

12 Comparison of three learning strategies in 1-3 year-old Danish children

13 Design and procedures Group PRE-TEST EXPOSURE POST-TEST FOLLOW-UP 3 MONTHS FOLLOW-UP 6 MONTHS MExp MExp C 10 MExp MExp C MExp C MExp C FFL MExp C 10 FFL MExp C MExp C MExp C FNL MExp C 10 FNL MExp C MExp C MExp C

14 Participants Characteristics MExp FFL FNL 1-2 yrs n = 27 n = 26 n = 15 Age (mo) 17.3 ± ± ± 2.74 (range) (13-21) (8-21) (11-20) Gender (boys/girls) 16/11 15/11 9/6 2-3 yrs n = 32 n = 33 n = 39 Age at first acceptance test (months) (range) 27.8 ± (22-34) 27.5 ± (22-36) 30.8 ± 4.20 (22-38) Gender (boys/girls) 12/20 19/14 18/21

15 Intensity Rating 15 MExp purée FFL purée FNL purée Carrot purée Sweet Salty Sour Bitter Umami Fattiness Homogeneity Coating Mealiness Artichoke Carrot

16 Intake (g) Intake of purée during exposures year-old Mexp (n=27) FFL (n=26) FNL (n=15) Exposure no

17 Intake (g) Robustness of learning Artichoke purée 1-2 year-old Mexp (n=27) FFL (n=26) FNL (n=15) 0 Pre-test Post-test 3 mo follow-up 6 mo follow-up

18 Intake (g) Intake of purée during exposures year-old Mexp (n=32) FFL (n=33) FNL (n=39) Exposure no

19 Intake (g) Robustness of learning Intake of MExp purée, 2-3 yrs old Mexp (n=32) FFL (n=33) FNL (n=39) Pre-test Post-test 3 mo follow-up 6 mo follow-up

20 Non-eaters : resistant to acceptance change over time Defined as Children with intakes below 20g at all exposures (10% of serving size) AND no development in intake across exposures All study groups 1-2 year-old ~ 15% 2-3 year-old ~ 30-40% Characteristics?

21 Flavour consequence learning based on pharmacological components of foods

22 Repeated exposure and flavour-flavour learning change acceptance Repeated exposure is a successful way of changing the majority of children s acceptance of a novel food Offering a familiar liked flavour with the novel food may promote tasting in children with high neophobia The efficiency of the strategies seems to be sensitive to age Learning is stable for 6 months, possibly longer

23 An artichoke effect? similar results with other new foods (Chinese radish etc.) watch out for boredom effects : every day-> boredom too rare exposure-> no effect ( forgetting ) comparison of 2 times/week with 1 time/week and 1 time/2weeks: 1 time/2 weeks most effective learn to accept (e.g. 4) new foods presented in an alternating sequence

24 Conclusions Food preferences are incidentally learned and outside conscious control, but healthy food preferences can be learned Use insights from the psychology and neurobiology of eating behaviour

25 A challenge Since it is virtually certain that sustainability concerns imply that we have to change dramatically the foods we eat, we need to develop rewarding, healthy foods also from unconventional materials develop methods to change preferences that are also effective for adults and elderly people

26 Enhedens navn Take home messages The overwhelming majority of taste preferences are acquired by incidental learning Learning starts already in the foetus state and is also influenced by flavours eaten by lactating mothers Conditional learning shapes development of taste preferences - repeated exposure - flavour-flavour learning - flavour-nutrient learning Humans can learn to like and accept any flavour/food