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Professor Glenn Wilson, Gresham College, London

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Title: THE SCIENCE OF LOVE: IS THERE SUCH A THING? Author: Psychology Last modified by: j.franklin Created Date: 10/29/2004 12:55:06 PM Document presentation format – PowerPoint PPT presentation

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Title: Professor Glenn Wilson, Gresham College, London


1

FEAST OR FAMINE?
THE PSYCHOLOGY OF EATING
  • Professor Glenn Wilson, Gresham College, London

2
TOO LITTLE, TOO MUCH
  • Eating is a major problem.
  • In the Developing World many people die because
    they dont have enough food.
  • In the West, people die more often because they
    are surrounded by too much. Either they overeat
    and become susceptible to obesity-related
    diseases or they starve themselves by compulsive
    fasting in the midst of plenty. Anorexia is a
    disease of the affluent middle-classes, not the
    poor.
  • Around 10 of teenage girls in the UK have some
    kind of eating disorder and there has been a 13
    increase over the last decade (Micali et al,
    2013).

3
WEIGHT STEREOTYPES
  • Popular belief that people are responsible for
    their own body shape.
  • Negative traits are commonly ascribed to
    overweight people which explain and blame them
    for their condition (e.g. lazy, undisciplined).
  • Some negative stereotypes also attach to slim
    people (e.g. vain, bitchy, mean).
  • Yon Cassius has a lean and hungry look . He
    thinks too much - such men are dangerous.
  • (Julius Caesar).

Survey of 1800 women aged 18-40 (Glamour, 2012)
4
GENETIC INFLUENCE
  • Body weight depends on interplay among many
    genetic and environmental forces.
  • Twin studies show 40-70 heritability (Herrera
    et al, 2011). Many genes involved 40 locations
    so far implicated in various appetite, energy
    storage and metabolism processes.
  • The best-known obesity-risk gene (FTO) is
    associated with a failure of satiation after
    eating (Karra et al, 2013).
  • Epigenetics (gene expression effects without DNA
    alteration) also have impact.
  • All of this makes control of weight very
    difficult.
  • Though often thought of as faulty the survival
    advantage of obesity genes in lean times is
    obvious.

5
EATING HABITS
  • Eating, drinking and exercise styles relate to
    obesity in complex ways. In a study of 1356 UK
    adults (Wilson 1985), body weight was associated
    with lack of exercise, overall food intake and
    eating in response to emotional stress. The
    latter seemed to reflect difficulty in
    maintaining dietary restraint in constitutionally
    heavy people. Diets tend to collapse at times
    when people are lonely, stressed or frustrated.
  • Sugar consumption and daily drinking were
    unrelated to body weight or health problems
    healthy people perhaps allow themselves more
    luxuries.

6
COMFORT EATING
  • When a sports team loses, their fans eat more
    junk food the next day.
  • Consumption of high calorie food increases on
    Monday in a city whose NFL team has lost on
    Sunday, whereas it decreases in the victors city
    (Cornil Chandon, 2013). Effect is greater in
    cities with the most committed fans, when
    opponents are equally matched and defeats narrow.
    Similar findings with French soccer fans.
  • A self-affirmation procedure (ranking and
    discussing core values) showed promise in
    countering the effect of a sports loss.

7
PERSONALITY AND BMI
  • Impulsivity is the strongest personality
    correlate of weight gain.
  • People get gradually heavier with age but those
    in top 10 for impulsivity averaged 24lbs more
    than those in the bottom 10.
  • Extravert people were also heavier
    Conscientious and Agreeable people tended to be
    thinner.
  • Those high in novelty-seeking were less
    successful in a weight management programme
    (Cloninger et al 2007).
  • Diet and exercise require commitment and
    restraint, which are lacking in certain
    individuals.

Longitudinal study of 1,988 adults in Baltimore
(Sutin et al 2011).
8
HUNGRY SHOPPERS
  • People who shop in a supermarket when hungry
    dont buy more food but do buy more high-calorie
    products (Wansink Tal, 2013). Subjects
    food-deprived for 5 hrs chose 5.72 high calorie
    products, vs 3.95 for sated controls. Interpreted
    as an effect of food insecurity.
  • Suggested that weight-watchers should have a
    snack before shopping or go after lunch. Good to
    take a list (ideally not children).


9
THINKING YOURSELF FULL
  • It is possible to trick people into feeling less
    hungry.
  • Brunstrom et al (2012) used a soup bowl that
    would covertly refill or lower its quantity as
    people ate from it. Immediately afterwards,
    self-reported hunger was based on how much they
    had actually consumed. However, after 2/3 hours
    hunger went with how much they thought they had
    consumed (memory of bowl size).
  • Food labels emphasising light and diet
    ingredients may be counterproductive, making us
    think we are less satisfied (so we eat more
    later).

People shown a large quantity of fruit that has
supposedly gone into their smoothie feel more
full afterwards (Brunstrom 2012).

10
TV MAKES YOU FAT
  • Watching TV contributes to obesity in several
    ways.
  • Viewers are sedentary for long periods.
  • If they snack while watching they lose track of
    how much they have had and consume more later
    (Mittal et al, 2011).
  • If the content of the TV programme is
    food-related or depressing they will eat even
    more of any food that is handy (Laran, 2013).


11
SLEEP DEPRIVATION
  • Late bedtimes allow more waking time for eating
    and late-night snacks tend to be more fattening
    (Spaeth et al 2013).
  • Also, sleep loss is apparently stressful.
    Decreased activity in cortical evaluation regions
    of the brain (frontal and insular cortex)
    together with increased amygdala activity prompts
    desire for high-calorie, fattening foods (Greer
    et al 2013).


12
SOCIAL INFLUENCES
  • People eat more in company than when alone. The
    social facilitation effect is stronger for
    friends/family than with strangers. Several
    reasons (1) Eating is a shared activity that
    consolidates social ties. (2) Meal lasts longer,
    giving more time to eat. (3) Conversation is
    distracting, so self-monitoring is impaired (c.f.
    TV viewing).
  • Eating with friends 18 calories, Viewing TV
    14 (Hetherington et al 2006).
  • People dining in twos tend to match their
    intake. Women eating with men eat more daintily
    than by themselves or with other women.

Women eat less when men are present than with
other women. Men not affected by company. (Young
et al 2009).
13
OBESITY CONTAGION
  • Social network analysis (Christakis Fowler,
    2010) indicates that obesity spreads like a
    virus. Friends have similar body build
    neighbours do not. Norms for acceptable body
    build, portion size, etc. may be passed among
    friends to influence weight.

14
PRIMING INDULGENCE
  • Seeing overweight people can lead us to eat more
    (Campbell Mohr, 2011).
  • People walking through a lobby answered survey
    questions that included a picture of either an
    overweight or normal-weight person.
  • Afterwards they helped themselves to a bowl of
    wrapped sweets as a thank you.
  • Those who saw the larger model took more sweets
    than the one who saw the thinner image (means of
    2.2 vs 1.4).
  • Four other studies confirmed this anchoring
    (reassurance?) effect.

Sticking overweight images on the fridge door may
have a reverse effect, shifting the idea of what
is normal.

15
CONTROL STRATEGIES
  • Many behavioural tips for controlling food
    purchase and consumption have been offered
  • (1) Dont buy jumbo packs, multi-buy offers,
    snacks/sweets, meal-deals.
  • (2) Store tempting foods well-packaged out of
    sight/reach (not in office drawer or glove box of
    car).
  • (3) Keep a healthy option to hand
  • (fruit or unsalted nuts).
  • (4) Drink water rather than fizzy and sugary
    drinks.
  • (5) Decide serving size in advance.
  • (6) Take your time when eating.
  • (7) Dont eat while doing other things
  • Frequent use of such strategies discriminates
    normal from overweight people but not overweight
    from obese (Poelman et al, 2013).


16
SELF-MONITORING
  • A key element in behavioural weight management
    programmes is some form of recording of eating
    patterns, weight or exercise (e.g., weighing self
    first thing every morning, or regular waist
    measurement).
  • Paper diaries, websites and phone aps can be
    helpful.
  • Does not seem to matter exactly what is
    monitored provided it is done on a regular basis
    (Burke et al, 2011).
  • Motivational, and may detect patterns, giving
    early warning.


17
SLIMMING GROUPS
  • Slimming classes like Weight Watchers are more
    successful than individual weight-loss programmes
    set up by doctors (Pinto et al, 2013).
  • These are behaviourally oriented focus on
    changing eating habits and promoting exercise.
  • Usually led by trained peer counsellors who have
    achieved their own weight loss.
  • Social context contributes to motivation and
    makes the treatment affordable.


18
ANOREXIA
  • Pathological dieting, combined with denial of
    any problem.
  • Most common in young women aged 12-19 (10x F/M).
  • Become fearful of fat, obsessed by
    food/calories, develop rituals around
    eating/mealtimes and avoid food deceitfully
    (e.g., pushing food around plate and hiding it in
    napkin).
  • Some follow pro-anorexia websites and smoke/take
    drugs rather than eat.
  • May be maintained by endorphin highs evoked by
    starvation (Brindisi Rigaud, 2011).
  • Can be life-threatening highest mortality of
    any mental illness (5-10 for every decade
    untreated). However, most (50-70) get better
    within 2ys.
  • .

19
BODY IMAGE DISTORTION
  • Anorexics overestimate their size. See
    themselves as fat (or claim to so as to justify
    food-avoidance?)
  • Asked to adjust a mirror until the reflection is
    accurate they make themselves fatter than they
    really are.
  • May turn sideways to go through a doorway they
    would comfortably fit head-on.
  • Misperception applies specifically to
    themselves, not to others around them (Guardia et
    al, 2012).
  • If not thinking themselves fat, may be proud of
    their bony form, believing themselves to be
    attractive.

20
RETREAT FROM PUBERTY
  • Anorexia is strongly associated with onset of
    puberty (which gets earlier). Trigger may be
    observation of bodily changes like breast hip
    enlargement, which arouse fear they are getting
    fat.
  • A more psychoanalytic idea is that anorexia is
    specifically focused on avoidance of menstruation
    and a fear of growing up and assuming adult
    responsibilities. Carbohydrate intake seems
    geared to keep weight just below the level where
    cycle would commence.
  • Recovering anorexics who regain normal
    luteinising hormone responses to LHRF show
    greater adolescent conflict on a repertory grid
    measure (Miles Wright, 2011).

21
PERSONALITY AND ANOREXIA
  • A particular set of personality traits is
    associated with anorexia (introversion, anxiety,
    perfectionism, OCD). Often pride themselves in
    self-control.
  • A connection with autistic spectrum disorders
    has been suggested (female Aspergers).
  • Some of these associations diminish with
    recovery, so may be a result of the starvation
    effects on the brain rather than pre-existing
    causes of the disorder (Cassin von Ranson
    (2005).

22
THE ANOREXIC BRAIN
  • When people look at body images, input is via
    the medial occipital area (mOC), then the
    fusiform body area (FBA) to the extrastriate body
    area (EBA). Suchan et al (2013) found a lower
    density of neurons in the EBA in anorexic
    patients and reduced input from FBA. This
    weakened connectivity between FBA and EBA might
    account for the development of anorexia, or could
    be a result of it.
  • Other studies have shown increased activity in
    emotional brain centres in response to food and
    body stimuli relative to controls (Zhu et al,
    2012).

23
SPRING BIRTH
  • Anorexia is more common in those born March to
    June (Northern Hemisphere). A similar
    relationship applies for major depression.
  • Probably due to vitamin D deficiency in the
    mother during winter gestation. Allen et al
    (2013) found Australian mothers with low vitamin
    D (measured at 18 wks pregnant) were more likely
    to have teenage daughters with eating disorders.

Data from meta-analysis of 4 UK cohorts, N 1293
anorexics (Disanto et al 2011).
24
MANOREXIA
  • Concern with muscularity may be a male
    equivalent of female anorexia.
  • Field et at (2013) found 9.2 of male
    adolescents had high concerns re muscularity
    (only 2.5 concerned about thinness).
  • Often leads to use of supplements (e.g. growth
    hormone, steroids) harmful to health.
  • Those concerned with thinness more prone to
    depression than those with muscularity concerns.
  • Body image problems in general more common in
    homosexual men.

25
BULIMIA
  • Binge eating of high calorie food is followed by
    purging or self-induced vomiting.
  • Stomach acids can damage throat, cause tooth
    decay bad breath. Also more common in young
    women but weight likely to be normal (Princess
    Diana).
  • Men not immune (John Prescott, Elton John).
  • Whereas anorexia goes with anxiety and
    constraint, bulimia relates to impaired
    self-regulation and impulse control (Marsh et al,
    2009). Comorbid with borderline personality
    disorder, substance abuse, shoplifting,
    self-mutilation and sexual disinhibition.

26
TREATMENT
  • May be necessary at first to hospitalise and
    force-feed.
  • CBT (modification of beliefs attitudes) is
    favoured treatment but co-operation not always
    forthcoming.
  • Important to look at motivation and ensure
    readiness to change.
  • May need to treat co-occurring problems such as
    anxiety, perfectionism, depression, substance
    abuse and attention deficit.
  • Drugs (e.g. SSRIs) may help, especially if
    depression is involved.
  • Some experimental work with deep brain
    stimulation, but this is a last resort.
  • The Maudsley Model (Le Grange, 2005) involves
    the family in treatment, e.g., teaching parents
    how to supervise meals. However, family attitudes
    are sometimes part of the problem.

27
FAD DIETS
  • Diet plans are a major industry.
  • Usually work by excluding certain types of food,
    thus reducing total calories if maintained
    long-term (Pagoto Appelhans, 2013).
  • Intermittent fasting also limits calorie intake,
    unless there is catch-up.
  • Compliance is poor because hunger increases and
    body goes into distress mode (release of stress
    hormones and lowered metabolism). When the diet
    stops there is rapid rebound to baseline or
    beyond.
  • Mostly unhealthy compared with balanced diets
    and exercise.
  • Breatharianism (living only on nutrients of sun
    and air) is most effective but eventually fatal.

28
SKINNY MODELS
  • Models in womens magazines are often airbrushed
    and unrealistic. Catwalk models are pressured to
    be dangerously thin so as not to distract from
    the clothes.
  • Proliferation of unhealthily thin models in the
    media has been linked to body dissatisfaction,
    substance abuse (smoking/heroin), eating
    disorders and depression (Grabe et al, 2008).
  • However, only women high in neuroticism suffer
    harmful effects of thin models (Roberts Good,
    2010).
  • Long exposure to thin-ideals can sometimes
    increase body satisfaction by prompting dieting
    and exercise (Knoblock-Westerwick Crane, 2012).

If Barbie were real she would have a 16in waist
and be infertile.
29
HELP FOR THIN WOMEN
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