Dietary Behavior
Zuzana Derflerová Brázdová


Evolutionary considerations
•Dietary habits are essential to survival
•Have played a central role in the evolution of mankind
•“Closed” programs vs. “open” programs
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•     The dilemma of omnivores:
•To explore the resources, but in a safe way.
•Dietary behavior differs from other health related everyday behaviors.
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Like/dislike mechanisms
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•Food neophobia (“I don’t like it, because I never tried it”)
•Food neophilia (occurs when little variation, boredom…)
•Preference for sweet tastes (concentrated energy, less likely to be toxic)
•Preference for salt taste (?)
•Learned food aversions
•Learned food preferences
•Food as reward
•Instrumental eating/drinking
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Learned food aversions
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•Food consumption associated with feeling ill, vomiting…
•One-trial learning
•Resistant to change
•Novel food more easily aversive
•Circumvents cognitive processes
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Learned food preferences
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•Food consumed associated with
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•Pleasant meal situation
•Recovery from illness
•Sweet tastes
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Instrumental eating/drinking
•Using a highly preferred activity as a reward for eating results in a decrease of the preference
for the food eaten.
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•Example: “If you eat this fish (drink the glass of milk), you can watch TV until midnight.”
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Liking is a powerful determinant of preference
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•Basic reasons for accepting/rejecting foods:
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•               1. Sensory-affective factors
•               2. Anticipated consequences
•               3. Ideational factors
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Basic reasons
•1. Sensory-affective factors
•Like or dislike for sensory aspects (taste, smell)
•Good tastes vs distastes
•Within-culture variation in food preference
•2. Anticipated consequences
•Beliefs about the consequences of ingesting food items
•Short-term effects: satiation, nausea
•Long-term: social status, health effects
•3. Ideational factors
•Acceptance/rejection due to knowledge about what foods are, their origin or symbolic meanings.
•Major effect on food rejections.
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Two major categories of rejection, based on ideational factors
•Inappropriate (sand, paper…) – most culture-wide rejections belong here
•Disgusting – strong sensory-affective loading, elicit nausea (animals, animals products, sea
products…)
•1. Distaste vs danger
•Learned food aversion
•               vs
•Allergic reaction
•2. Disgust vs inappropriate
•Disgust is learned (infants don’t have it). Psychological contaminants, faeces… Typical facial
expression
•Inappropriate: information
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3. Good tastes vs beneficial
•Exposure is necessary for the acquisition of likings
•Exposure can increase liking
•Association of food with positive post-ingestive consequences
•Social influences are strong in acquisition of likes/dislikes (esp. children)
•Cognitive factors influencing dietary habits may be more elementary than the acquisition and
retention of nutrition knowledge
•Information /education can lead an individual to a specific food, and may make him taste it, but
what happens next is determined by other factors.
•“You can lead a horse to water, but you can’t make him drink.”
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Definitions
•Preference = refers to a choice of one item rather than another. Assumes availability.
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•Liking = an affective response to food. Usually verbal self-reports.
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Prerequisites for individual behavior change
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•Knowledge  (I know - what)
•Attitude (I want to – why)
•Behavior (I can do it – how)
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•Complex relations between
•    knowledge – attitude – behavior (k-a-b)
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Behavior changes
•Most health-related risk behaviors have positive short-term consequences and negative long-term
consequences
•Health-related protective behaviors have negative short-term consequences (at least initially) and
positive long-term consequences
•Everyday health-related behaviors are determined by the interactions between:
•Situations (occasions for…)
•Consequences (positive, negative, short-term, long-term…)
•Skills
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Dietary behavior change
•Change situations
•Change consequences
•Learn skills
•“Think small”
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•     Don’t be frustrated:
•For any given topic in public health there are always more people who are uninterested than those
who are highly interested and motivated.
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