Dieting, restraint and disinhibition - week/lecture 7

Question 1

2 visualisations of a healthy diet

Answer 1

eating pyramid and eat well plate

Question 2

how do unhealthy diets lead to CHD?

Answer 2

○ Atherosclerosis
○ Thrombosis
○ Myocardial infarction
○ 1 in 6 men and 1 in 10 women die from it
○ HDLs are good cholesterol
○ LDLs bad cholesterol
○ LDLs stick to artery walls and can lead to build up of plaque (atherosclerosis) leading to heart attack
○ HDLs carry LDLs away from artery walls

Question 3

how do unhealthy diets lead to type 2 diabetes?

Answer 3

○ Insulin resistance
○ CHD

Question 4

energy intake is through

Answer 4

○ Food (carbs, lipids, proteins)
○ Alcohol

Question 5

energy expenditure is through

Answer 5

○ Basal metabolism (60-75%)
○ Thermogenesis (10%)
○ Physical activity (15-30%)

Question 6

onset of the dieting industry

Answer 6

1960s

Question 7

dieting industry

Answer 7

• Onset of dieting boom in 1960s
  
  • Creating/response to demand?
  • Weight watchers
    ○ 1 million members signed up
    ○ Profits of £18 million in 2013
  • Obese vs general population
    ○ Promotion of thinness
    ○ Emphasises efficacy of dieting for change
    ○ Expanding the market
    § ‘lose those last few pounds for summer’

Question 8

motives for weight loss

Answer 8

• O’Brien et al., (2007)
  ○ Appearance; health; mood
  
  • Motivations for weight loss may impact on subsequent success of dietary intervention
    ○ Ogden, Karim, Choudry and Brown (2007)
    ○ Positive intentions and less positive attitudes towards target foods associated with greater success in dieting
  • Low motivation, self-esteem, increased body dissatisfaction and increased dieting attempts associated with reduced success (Teixeira et al., 2002)

Question 9

seasonality of dieting

Answer 9

• Griffiths, Cowley-Court, Austen et al., (2022) hypothesised people diet in spring to prepare their bodies for summer
  • Seasonal frequencies of 69 dieting hashtags on twitter (2012-2019; Griffiths et al., 2022)

Question 10

body dissatisfaction

Answer 10

• A discrepancy between perceived body size and ideal body size; feelings of discontent with shape and size

Question 11

body dissatisfaction - quality of evidence

Answer 11

• Quality of evidence - prospective studies
  ○ Bucchianeri et al., (2013); Paxton et al., (2006); Presnell et al., (2004); Wojtoowicz and Ranson (2012)
  • Stice and Shaw (2002)
    ○ Perceived pressure to be thin, thin-ideal internalisation and elevated body mass linked to body dissatisfaction
    ○ Dieting and negative affect mediating variables

Question 12

efficacy of dieting for weight loss

Answer 12

• Types of diet
  
  • Importance of physical activity for energy balance
  • Set point theory (Harris, 1990)
    ○ Genetics play important role in determining weight
    ○ Small modifications through behavioural change
    ○ Body ‘defends’ set point
    ○ Should weight loss be encouraged through dietary restriction?

Question 13

types of diet

Answer 13

calorie restriction
specialised
high protein

Question 14

types of diet - calorie restriction

Answer 14

• Weight watchers
  
  • Slimming world
  • 5:2
  • Intermittent fasting
  • Pre-packaged foods
  • Meal plans
  • Meal replacement

Question 15

types of diet - specialised

Answer 15

• Food combining (e.g., Hay Diet)
  ○ Acidic foods - protein, fruits
  ○ Alkaline foods - CHO
  ○ Incorrect digestive environment –> weight gain
  ○ Limited scientific evidence; anecdotal (IBS)
  • Blood type
    ○ Immune response to foods varies according to blood type
  • Single food diets
    ○ E.g. cabbage soup, grapefruit

Question 16

types of diet - high protein

Answer 16

• Paleo diet - ‘caveman’
  ○ Meat, seafood, eggs, nuts, seeds, fruit and veg, spices
  ○ Advocated as a long term healthy eating plan
  ○ Better off mimicking activity levels?
  ○ Eat like this 80% of the time
  
  • Atkins diet (keto - more extreme)
    ○ CHO cause weight gain; saturated fats not as bad as first assumed
    ○ Reduced sugar and refined CHOs
    ○ Nutrient dense, unprocessed foods plus supplementation
    ○ Ketosis - fat instead of glucose used for fuel

Question 17

atkins diet - pros

Answer 17

○ Rapid weight loss
○ Good for short term weight reduction for medical reasons
○ Reduced intake of sugar and processed grains
○ Reduced appetite (monotomy?)

Question 18

atkins diet cons

Answer 18

○ Meat, sat fat, cholesterol, low fibre
○ Risk of CHD, cancer
○ Goes against food pyramid and balanced diet
○ Deficient in vitamins and minerals
○ Cognitive implications of low glucose availability
○ Limited evidence in support

Question 19

paleo diet

Answer 19

○ Meat, seafood, eggs, nuts, seeds, fruit and veg, spices
○ Advocated as a long term healthy eating plan
○ Better off mimicking activity levels?
○ Eat like this 80% of the time

Question 20

atkins diet

Answer 20

○ CHO cause weight gain; saturated fats not as bad as first assumed
○ Reduced sugar and refined CHOs
○ Nutrient dense, unprocessed foods plus supplementation
○ Ketosis - fat instead of glucose used for fuel

Question 21

food combining diet

Answer 21

○ Acidic foods - protein, fruits
○ Alkaline foods - CHO
○ Incorrect digestive environment –> weight gain
○ Limited scientific evidence; anecdotal (IBS)

Question 22

blood type diet

Answer 22

Immune response to foods varies according to blood type

Question 23

dieting as a risk for later weight gain - evidence

Answer 23

• Pelissier et al., 2023
  ○ Systematic review
  ○ Impact of dieting on body weight and composition among normal weight individuals
  ○ 18 studies
  ○ Of 8 intervention studies
  § 75% reported metabolic adaptations in response to weight loss that favoured weight regain
  ○ Observational studies
  § 80% of the ten studies found that dieters have a higher body weight than non-dieters
  ○ Differences in definitions of ‘diet’ and heterogeneity in methods used to assess dieting status
  ○ Dieting potentially a major risk factor for weight gain in longer term among normal weight individuals

Question 24

restraint

Answer 24

• Deliberate attempt to inhibit food intake in order to maintain weight or prevent gain
  
  • Herman and Mack 1975 restraint theory
  • Self-imposed dietary rules
  • Effortful process
  • Psychological and physical impact of restraint

Question 25

what is disinhibition

Answer 25

• Induction of over eating among restrained eaters
  
  • Inability to maintain cognitive control of intaked

Question 26

disinhibition - preload studies

Answer 26

• Preload studies (Herman and Mack, 1975)
  ○ High vs low calorie preload followed by multiple item taste test in controlled env
  ○ Evaluate differences between low and high restrained eaters
  ○ Preload condition variations:
  § No preload
  § One milkshake
  § Two milkshakes
  ○ Taste test
  ○ Consumption monitored
  ○ Completion of questionnaires
  ○ Low restrained showed compensatory regulation in taste test
  ○ High restrained overconsumed following consumption of calorie dense preload (counterregulation)

Question 27

The Boundary Model (Herman and Polivy, 1984)

Answer 27

model for disinhibition

Question 28

What factors affect disinhibition in restrained eaters?

Answer 28

1. Perceived caloric content and food category; (Knight and Boland, 1989; Mills and Palandra, 2008)

    2. Food cues (e.g. Federoff, Polivy and Herman, 2003)
   
    3. Negative affect (e.g. Polivy and Herman, 1999)

Question 29

1. Perceived caloric content and food category; (Knight and Boland, 1989; Mills and Palandra, 2008) for disinhibition in restrained eaters

Answer 29

i. ‘Forbidden foods’
- Wasink, Cheney and Chan (2003)
® Exploration of comfort foods
® Gender and age differences
- Soetens, Braet, Van Vlierberghe and Roets (2008)
® Temptation vs control group
® High restraint/high disinhibition
® High restraint/low disinhibition
® Low restraint
- Prohibition with exposure may backfire and increase subsequent consumption
- Particularly prominent in disinhibited restrainers

Question 30

2. Food cues (e.g. Federoff, Polivy and Herman, 2003) for disinhibition in restrained eaters

Answer 30

i. Sight, smell - inhibition of dieting goals
ii. External eating
- DEBQ; power of food scale
® Inability to resist env cues (Braet and van Strien 1997); sensory initiation of eating
® Links with obesity
® Schachter et al., 1968 - reliance of external and emotional cues to control appetite
® ‘Bakery effect’
® Personality trait

Question 31

3. Negative affect (e.g. Polivy and Herman, 1999) for disinhibition in restrained eaters

Answer 31

Dysphoria, sadness, task failure

Question 32

disinhibition and weight

Answer 32

○ Linked to higher BMI (overweight/obesity)
○ Predictive of poor success when dieting
§ Weight gain after dieting
○ Associated with
§ Less healthy food choices
§ Low self esteem
§ Low PA
§ Bingeing
○ Opportunistic eating or thrifty eating behaviour

Question 33

how can we measure restraint?

Answer 33

• Revised Restraint Scale (Herman & Polivy, 1984)
  
  • Three Factor Eating Questionnaire (TFEQ, Stunkard &
    Messick, 1985).
  • Dutch Eating Behaviour Questionnaire (DEBQ, van Strien et al., 1986).
    ○ High scorers on the RS and DEBQ characterised by both successful and unsuccessful restriction (i.e. tendencies to disinhibit). Is this a problem?

Question 34

can restraint measures predict eating behaviours?

Answer 34

• Need to distinguish between restrained eating & current dieting (Lowe, 1993)
  ○ Different ‘purpose’ – to lose or to avoid gaining weight?
  ○ Two-factor measurement (restraint & tendency to overeat/disinhibition).
  
  • Relevance of flexible versus rigid restraint?
    ○ Rigid = high disinhibition
    ○ Flexible = low disinhibition, lower BMI, frequency of binges, energy intake, higher probability of weight reduction

Question 35

distraction and intake

Answer 35

• Robinson et al., (2013) meta-analysis
  ○ Immediate and delayed increase in intake after distracted food consumption
  ○ Paying attention to food linked to reduced intake and enhanced food memory.
  ○ Principles of ‘Attentive’ eating may be important for weight-loss interventions.
  1. Eating devoid of distractions
  2. Prompting memory recall of food previously consumed
  3. Being aware of food consumed
  4. Enhancing memory of food consumed

Question 36

attentive eating intervention

Answer 36

Robinson, Higgs, Daley, Jolly, Lycett… (2013). Development and feasibility testing of a smartphone based attentive eating intervention

Question 37

Robinson, Kersbergen and Higgs (2014) study

Answer 37

8 overweight and obese women
- Fixed lunchtime meal
- Focussed attention condition vs. control condition
- Outcomes:
○ Consumption of snack food at free eating session later that day
○ Memory of meal.
- Results:
○ Snack consumption 30% lower in focused condition
Memory for the meal was NOT improved.

Question 38

role of distraction of SSS

Answer 38

Brunstrom & Mitchell (2006) distraction study – Part 1

- Brunstrom & Mitchell (2006) distraction study - Part 2 
	○ Desire to eat, pleasantness and intensity ratings for Jaffa Cakes and for two uneaten foods, measured before and at 3 time points after consuming 5 Jaffa Cakes. 
	○ Non-distracted participants showed a reduction in desire to eat the Jaffa Cakes in comparison to uneaten food (SSS). 
	○ Distracted participants maintained a desire to eat all foods. 
	○ Is distraction important in the context of obesity?

Question 39

cognitions, distraction and dieting - the relationships

Answer 39

• Distraction and intake
  
  • Dieters report higher levels of preoccupying cognitions than do non-dieters
  • Associated with deficits in the functioning of working memory components

Question 40

cognitive control of eating; cognitive performance - limited cog capacity hypothesis

Answer 40

• Limited Cognitive Capacity Hypothesis (Boon, Stroebe, Schut & Ijntema (2002)
  ○ Disinhibited intake occurs in restrained eaters if there are limitations on their cognitive capacity (demanding tasks), regardless of emotional component
  ○ High restrained eaters ate more when distracted compared to unrestrained eaters.

Question 41

Cognitive control of eating: relapse
The Abstinence Violation Effect

Answer 41

• The Abstinence Violation Effect (Marlatt & Gordon, 1985)
  ○ Negative cognitive, attributional and affective responses when returning to a substance following a period of self-
  imposed abstinence
  ○ Bulimia nervosa context; links with dieting success (Mooney
  et al., 1992)
  
  • Cognitive dissonance; high risk situations
  • Internal, stable & global attributions (e.g.,Grilo & Shiffman, 1994)
    ○ ‘All is lost’

Question 42

Ecological momentary assessment (EMA)

Answer 42

• EMA involves repeated sampling of an individual’s behaviours in their natural environment.
  
  • Typically collected via electronic diary or phone app.
  • Individuals are given instructions to record responses whenever they feel a particular way, in response to a particular event, or at predetermined intervals
  • Lots of data
  • Aims to minimise recall biases
  • Useful in understanding ‘in the moment’ thoughts, feelings and beliefs and can provide insights into individuals experiences.

Question 43

Systematic review of EMA: Randle et al., (2023)

Answer 43

• Review of EMA studies assessing appetite and affect in overweight or obese adults engaging in dieting, and to synthesize evidence on how these are associated with experiences of temptations and dietary lapses.
  ○ N = 10 studies
  ○ Evidence of within person changes in appetite and affect accompany temptations
  and lapses, and are observable in the moments precipitating a lapse
  ○ Negative abstinence violation effects apparent following a lapse
  ○ Employing coping strategies during temptations is effective for preventing lapses
  
  • EMA helps to identify real-time opportunities for intervention and support.

Question 44

restraint and working memory

Answer 44

• Poorer recall on a phonological similarity task (phonological loop) and slower planning times on the Tower of London Task (central executive; Green & Rogers, 1998).
  
  • Further evidence of deficits in performance on tasks targeting CE and PL (particularly phonological store; Vreugdenberg, Bryan & Kemps, 2003)
    ○ Mediating variable of body concern
  • Partially mediated by preoccupying thoughts about food, weight and body shape, but not by BMI or depressed affect (Kemps, Tiggemann & Marshall, 2004)