The psychology of obesity

1
The psychology of obesity

• Jane Ogden
• Professor of Health Psychology
• University of Surrey

2
Overview

• The causes of obesity
• The role of behaviour
• Obesity treatment
• Dietary interventions
• Medication
• Surgery
• What doesnt work?
• What works?
• How can obesity be treated effectively?

3
The rise in obesity
4
Obesity Trends Among U.S. AdultsBRFSS, 1985
(BMI 30, or 30 lbs overweight for 5 4
person)
5
Obesity Trends Among U.S. AdultsBRFSS, 1986
(BMI 30, or 30 lbs overweight for 5 4
person)
6
Obesity Trends Among U.S. AdultsBRFSS, 1987
(BMI 30, or 30 lbs overweight for 5 4
person)
7
Obesity Trends Among U.S. AdultsBRFSS, 1988
(BMI 30, or 30 lbs overweight for 5 4
person)
8
Obesity Trends Among U.S. AdultsBRFSS, 1989
(BMI 30, or 30 lbs overweight for 5 4
person)
9
Obesity Trends Among U.S. AdultsBRFSS, 1990
(BMI 30, or 30 lbs overweight for 5 4
person)
10
Obesity Trends Among U.S. AdultsBRFSS, 1991
(BMI 30, or 30 lbs overweight for 5 4
person)
11
Obesity Trends Among U.S. AdultsBRFSS, 1992
(BMI 30, or 30 lbs overweight for 5 4
person)
12
Obesity Trends Among U.S. AdultsBRFSS, 1993
(BMI 30, or 30 lbs overweight for 5 4
person)
13
Obesity Trends Among U.S. AdultsBRFSS, 1994
(BMI 30, or 30 lbs overweight for 5 4
person)
14
Obesity Trends Among U.S. AdultsBRFSS, 1995
(BMI 30, or 30 lbs overweight for 5 4
person)
15
Obesity Trends Among U.S. AdultsBRFSS, 1996
(BMI 30, or 30 lbs overweight for 5 4
person)
16
Obesity Trends Among U.S. AdultsBRFSS, 1997
(BMI 30, or 30 lbs overweight for 5 4
person)
17
Obesity Trends Among U.S. AdultsBRFSS, 1998
(BMI 30, or 30 lbs overweight for 5 4
person)
18
Obesity Trends Among U.S. AdultsBRFSS, 1999
(BMI 30, or 30 lbs overweight for 5 4
person)
19
Obesity Trends Among U.S. AdultsBRFSS, 2000
(BMI 30, or 30 lbs overweight for 5 4
person)
20
Obesity Trends Among U.S. AdultsBRFSS, 2001
(BMI 30, or 30 lbs overweight for 5 4
person)
No Data lt10 1014
1519 2024 25
21
Obesity Trends Among U.S. AdultsBRFSS, 2002
(BMI 30, or 30 lbs overweight for 5 4
person)
(BMI ?30, or 30 lbs overweight for 54 person)
No Data lt10 1014
1519 2024 25
22
Obesity Trends Among U.S. AdultsBRFSS, 2003
(BMI 30, or 30 lbs overweight for 5 4
person)
No Data lt10 1014
1519 2024 25
23
Obesity Trends Among U.S. AdultsBRFSS, 2004
(BMI 30, or 30 lbs overweight for 5 4
person)
No Data lt10 1014
1519 2024 25
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Why this increase?

• Genetic theories
• One obese parent 40 risk of obese child
• Two obese parents 80 risk of obese child
• Twin / adoptee studies66-70 of variance
  accounted for by genetics
• But
• Cannot explain changes over time
• Cannot explain migration data

25
Obesogenic environment

• Sedentary lifestyle
• Less manual labour
• More car use
• Town planning
• Remote controls
• Mobile phones
• More fast food
• Less cooking
• More eating out
• More snacking

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A role for behaviour

• Physical activity
• Eating behaviour

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(No Transcript)
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Why do exercise?

• Habit
• Learning
• Childhood
• Attitudes
• Costs and benefits
• Peer norms
• Social norms
• we like it

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• Eating behaviour

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Why do we eat what we eat?

• Hunger?

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The meaning of food

• Emotional regulation
• Social interaction
• Habit

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Why do we eat?

• Habit
• Learning
• Childhood
• Costs and benefits
• Peer norms
• Social norms
• we like it
• we try NOT to eat it

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Basically ..

• We eat because at the time the benefits of eating
  out weigh the costs

35
Therefore.

• Good evidence for genetic basis to obesity
• Cannot explain rapid increase
• Role for obesogenic environment
• Highlights role for behaviour
• Activity and eating
• Role of psychology
• Obesity treatment?
• Needs to address behaviour
• Needs to address psychology of behaviour
• What works / doesnt work? / why?

36
Dietary interventions

• Traditional programmes
• Eat less
• Lost weight
• but 99 regained weight
• Multidimensional packages
• Lifestyles changes, cognitive restructuring,
  reasonable weights, nutritional information, self
  monitoring, relapse prevention, screening
  patients, follow ups
• 60 lose weight
• Up to 95 regain weight in longer term

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• Why dont they work?

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Dieting

• Trying to eat less
• But.
• Most dieters show episodes of overeating
• The what the hell effect

39
Why dont dietary interventions work?

• Trying to change embedded habit
• Rebound back to old habit
• High effort
• Restriction takes away function
• Emotional regulation
• Social interaction
• AND imposes denial
• Creates preoccupation with food
• Lowers mood
• Exacerbates benefits of eating
• Offers no costs of eating

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What can we learn?

• Behaviour is difficult to change
• Habits
• Function of food
• Social
• Emotional regulation
• Communication
• Benefits out weigh costs
• Dieting exacerbates benefits
• Denial

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• Alternatives?...............

42
Medication

• Orlistat (Xenical)
• Prevents fat absorption
• Causes unpleasant side effects
• Qualitative study
• The experience of taking Orlistat as a window
  into
• Successful behaviour change
• (Ogden and Sidhu, 2006)

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Causes of obesity

• Medical
• Im not a big eater, sometimes I dont even want
  to eat but I just eat coz I have to eat coz Im
  diabetic (Frances).
• Behavioural
• I ate too much. I ate all the wrong foods. I
  did a static job.. And the bigger I got the more
  I ate. And thats about it really. I used to
  eat a colossal amount..it was bacon, eggs,
  sausages, chips I used to eat loads and loads of
  meat. Beef, pork. I could eat two French
  sticks in one sitting (Matthew).

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Experiences of side effects

• I had near misses I dont break wind unless Im
  sitting on the loo. Its a fear thing I have
  had situations where Ive had to discard a pair
  of boxer shorts (David).
• messy, disgusting, horrible, unsafe, near
  misses, accidents, personal oil slick.

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Behaviour change?

• Showed behaviour change if
• Behavioural model of causes
• Visual side effects act as an education

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What can we learn?

• Drugs work by
• Encouraging a behavioural model of obesity
• See diet as the cause
• Create match between cause and solution
• Create short term costs of overeating

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Surgery

• Surgery
• Reduces stomach size
• Reduces food intake
• Can cause dramatic weight loss
• But has unpleasant side effects

48
Qualitative study

• In depth interviews
• 15 people who had had surgery
• (Ogden et al, 2005 2006)

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Role of food

• I used to think about food all the time..before
  I got married Id sit in bed reading recipe books
  thinking cor I fancy thatnow I think that would
  be good and that wouldnt

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Hunger

• The most incredible thing that has happened is
  lack of appetite the hunger pangs have gone Im
  sated when I eat

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Control over food

• If someone or something didnt stop me I would
  just continue. What the operation has done for
  me is that physically because my stomach is
  smaller I can only eat smaller mealsbecause I
  know I cant I dont

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What can we learn?

• Surgery works by
• Reduces function of food
• Changes habit
• Emotional regulation
• Social interaction
• Provides short term costs to overeating
• Taking away control from individual
• Relies upon stomach size NOT denial

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Therefore

• Obesity on the increase
• Obesogenic environment
• Behaviour
• Behaviour difficult to change
• Treatment alternatives
• Have psychological implications

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• How can we improve weight management?

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Need to change behaviour

• Avoid
• Avoid consequences of dieting
• Avoid denial
• Avoid making food more pleasurable
• Avoid exacerbating benefits of eating

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To Do.

• Acknowledge and address the psychology of obesity
• Address psychology of behaviour
• AND / OR change environment
• AND / take away control through surgery
• AND / OR offer surgery but support people through
  it