Transcript Eating Behaviour 3

Eating Behaviour
Unit PSYA3
Miss Bird
Homework due 
Essay question (January 2011)
Discuss the role of one or more factors that
influence attitudes to food. (4 marks A01 and 8
marks A02).
Essay plan or essay answer
AQA A Specification
Factors influencing attitudes to food and eating behaviour. For
Eating behaviour example: cultural influences; psychological influences (mood); and
social influences (health concerns/media).
Explanations for the success and failure of dieting.
Neural mechanisms involved in controlling eating behaviour.
Biological
explanations of Evolutionary explanations of food preference.
eating behaviour
In relation to either anorexia nervosa or bulimia nervosa:
Eating disorders
Psychological explanations.
Biological explanations, including neural and evolutionary explanations.
Today’s lesson
 Why do people diet?
 What is dieting?
 Restraint Theory and the Boundary Model
(Herman and Polivy, 1984).
 Key studies – Herman and Mack (1975), Wardle
and Beales (1988).
 Evaluation of Restraint Theory and key studies.
 Application of IDA.
Starter: Pair activity
 What diets have you heard of?
 Why do people diet?
 What does dieting involve?
 Why might some people be more successful
at dieting than others?
You have 5 minutes.
Why do people diet?
 To lose weight and ‘improve’ appearance.
 Primary motivation = body dissatisfaction.
 A consequence of body dissatisfaction is
the need to diet and lose weight in order to
change your body size and shape.
So…What is dieting?
Voluntary restriction of food intake in an attempt to encourage
weight loss (a behavioural and cognitive intervention).
Three basic forms of dieting associated with restriction of food
intake: 1. Restrict the total amount of food eaten.
2. Do not eat certain types of food.
3. Avoid eating for long periods of time.
The aim of losing weight then becomes the primary focus when
choosing what foods to eat and how much.
Restraint Theory
The boundary model (Herman and Polivy, 1984)
Why dieting may lead to overeating
Hunger
Min. level
Satiety
Max. level
Normal eater
Hunger
Diet boundary
Satiety
Restrained eater (Dieter)
Restraint Theory: Normal eater
 Food consumption is regulated by
biological processes to keep food
intake within a set range.
 Hunger keeps intake of food
above a specific minimum level.
 Satiety (feeling of
satisfaction/fullness) keeps intake
of food below a specific
maximum level.
 Your hunger and satiety levels are
determined by your body weight
set point (your biology).
 Within this set range, eating is
regulated by social, environmental
and psychological factors.
Hunger
Min. level
Satiety
Max. level
Set range
Normal eater
Restraint Theory: Restrained
eater (dieter)
 Dieters tend to have a larger range
between hunger and satiety levels
than normal eaters as it takes them
longer to feel hungry and more food to
satisfy them.
Hunger
Cognitive diet boundary
 Dieters also have a self-imposed,
desired intake of food – a cognitive
dietary boundary (what they think they
should eat and how much).
 If they exceed this diet boundary they
continue to eat until they reach satiety
(which is higher than that of a normal
eater).
 This consequently leads to overeating.
Satiety
Restrained eater
Independent task
Answer the 4 questions on the boundary
model in your booklet.
You have 5 minutes, then Q&A.
To summarise…
Therefore, the boundary model
(part of restraint theory)
attempts to explain why diets
may fail.
Factors that regulate eating/dieting
The role of genetics
 Suggested that body weight can be influenced
by genetic factors (e.g. inherited; ‘ob’ gene for
obesity).
 Genes may influence factors such as appetite
regulation, metabolic rate and the number of fat
cells a person has.
Factors that regulate eating/dieting
The role of social and environmental pressures
 Increases in portion sizes of meals can promote
overeating.
 Exposure to the ‘ideal’ body size and weight in the
media can influence food intake (SLT).
Cognitive factors
 Dieters may impose a cognitively-determined diet
boundary to control food intake (thoughts about foods).
Herman et al (2005)
Factors that promote overeating in dieters: 1.Distress – e.g. extreme anxiety.
2.Cravings – dieters more prone to experiencing
them due to food restrictions.
3.Pre-loading – portion of food given to people before
they are allowed free access to other foods – should
suppress appetite but can have the opposite effect
in dieters i.e. overeating.
Herman and Mack (1975)
Pre-load / taste test paradigm
45 female participants (dieters and non-dieters) were
given a pre-load food, either high or low calorie
(chocolate or crackers).
Participants then told they were taking part in a
taste preference test and were left alone to do
the taste test in their own time.
Observed how much of the food they ate.
FINDINGS: The dieters ate more in the taste test if they had the high calorie
preload (chocolate).
CONCLUSION: Restrained eating can result in over-eating.
Independent task
• Read the supporting research by
Wardle and Beales (1988).
• Outline the APFCC in your booklets.
You have 10 minutes, then Q&A.
Evaluation
Implications for obesity treatment
 Restraint theory suggests that food restriction can lead to
overeating.
 However treatment for obesity often recommends restraint as a
solution to excessive weight gain.
 Although obesity may not be caused by overeating (e.g. ‘ob’
gene), overeating may be a consequence of obesity if restraint is
recommended as a treatment (Ogden, 1994).
 Therefore not an appropriate treatment for obesity if theory is
correct.
Evaluation
Restraint theory has limited relevance
 Restraint theory suggests a link between food restriction and
overeating.
 Dieters, bulimics and anorexics report episodes of overeating.
 However, if trying not to eat results in overeating (according to
restraint theory), then how do anorexics manage to starve
themselves?
 Cannot explain restricting behaviour in anorexics (i.e. avoiding
meals, carefully weighing and portioning food) as according to
restraint theory, this should result in overeating and weight
gain, not severe weight loss.
IDA (A02)
In your booklets or on lined paper,
identify any relevant IDA for today’s
lesson content.
You have 10 minutes in pairs.
IDA (A02)
 Methodology.
 Gender bias.
 Nature vs. Nurture.
 Determinism vs. free will.
 Reductionism.
 Approaches – biological, cognitive,
learning.
Homework 
Research and make notes on
‘The theory of ironic processes of
mental control’ by Wegner (1994).
There is space in your booklets
for this information.