We eat in order to sustain ourselves and eating is something that mandatory for everyone in order
to gain energy/calories and nutrients to survive. Thus, we all need to have some sort of
relationship with food.
Boundary model – There are physiological and non-physiological (psychological) influences
on eating. In terms of physiological influences: The physiological feeling of hunger ensures we
don’t eat too little and the feeling of satiety ensures we don’t eat too much. Between satiety and
hunger (the middle range) is where physiological needs are satisfied and it is here where
psychological factors impact eating.
https://www.youtube.com/watch?v=8Ogsmh_czeY (17 mins ted talk) – Watch this video for the
test. The overall idea is this:
Mindlesss eating (eating w/o paying to attention to what or how much you’re eating) is very
common, particularly in North America. It is influenced by cues that we don’t acknowledge
(even if we learn these exist, we still rarely acknowledge they are causing us to eat). One
solution: Eat more mindfully – Eat less, enjoy more; tune into internal cues of satiety. Another
solution: Set up circumstances such that one can mindlessly eat well – Smaller plates, less
accessible junk food.
Additional influences on eating: We tend to match the quantities eaten by those we eat with (this
is called modelling). Also, we tend to eat more in groups than when alone (except when we feel
we’re being observed or evaluated by others).
In many samples, more women reported dieting than not! Thus, dieting for women had
become “normal” eating (think of a normal distribution).
How does dieting impact our boundaries for ingestion? Dieters create different boundaries for
eating (ex. I will eat this many calories or I will not eat after a certain time). Under non-
disrupted circumstances, dieters eat less than non-dieters, but… Dieters’ boundaries are
defined by cognitive factors more than non-dieters – non-dieters are relatively more tuned in to
sensory/physiological cues of satiety. (Example from the video: Parisian vs. Chicago person:
“why stop eating?” Paris: “I feel full” Chicago: “My plate is empty”)
Cognitive boundaries are more subject to disruption than sensory-based boundaries. They are
more likely to do accidental/impulsive overconsumption - Once the boundary is crossed, dieter
will eat more than a non-dieter who ate the same amount – known as the “What the hell”
phenomenon. This can be caused by emotional agitation, intoxication, and social pressure.
The consequence of restraint from eating can result in forms of withdrawal symptoms. This sets
up the person to eat more on average in the long-run than if we hadn’t restrained in the first
place. Typically, additional factors like negative emotional states interact with restraint to
induce bingeing in many dieters (rather than the restraint itself directly triggering binges – it
“sets the stage”)
Calorie restriction may help someone who is overweight lose weight (although there is a sizable
genetic contribution to body size). Many dieters fail to reach or maintain their newly acquired lower weight (A study followed 692 girls for 4 years – girls who dieted throughout had 3x
greater obesity risk).
Other than wanting to lose weight, here are a couple reasons why people restrict their eating:
1. Cultural emphasis on the value of thinness (this really mainly applies to only our current
generation as thinness is the “desired” aesthetic nowadays – in previous generations
where curves were more desired this may not have been the case). Interesting notes:
Women who are average in weight often feel overweight. Thinness is stereotypically
linked to success-related characteristics (self-control, power, etc.)
2. Impression management – Eating less and eating healthy stereotypically linked with
femininity. OTOH, eating more and eating unhealthy foods are stereotypically masculine.
Thus, people may change eating to project certain characteristics. One study showed that
women ate less in the presence of a man and ate even less when the male seemed like a
socially desirable partner.
Dieting history is linked to rates of anorexia nervosa, bulimia nervosa, and binge eating disorder.
Dieters and people with EDs are: Similarly preoccupied with weight (driving for thinness),
Characteristically dissatisfied with their bodies and intense concern for appearance, Intense
concern with restriction of calorie intake, Predisposition to binge, Less sensitivity and reliance
on satiety and hunger cues and rely more psychological cues (It can work both ways: They may
not eat when hungry and they may keep eating/eat too much when full)
(Note: most people who diet do not develop EDs but dieting is a risk factor for the development
Risk factors for development of EDs include: 1. Being overweight 2. Attempting to lose weight
through dieting 3. Being in higher socio-economic class 4. Acculturating to Western culture
(A study followed Egyptian women either attending a UK or Egyptian university and found that
those attended the UK 12% developed an eating disorder and those attending Egypt 0%
developed an ED). The prevalence of EDs within North America also varies with ethnicity
(Black adolescent females are less dissatisfied with body, fewer concerns with weight and have a
more positive self-image compared to White adolescent females).
In 2005, 500 000 Canadians reported having an ED. Incidence surged in years between 1950s
and 1995 but there have been relatively stable rates of incidence since then. 90% of severe EDs
are in “young females who live in a socially competitive environment” (No other psychological
disorder is that specific to a demographic). EDs have the highest mortality rate of all
Bulimia Nervosa (BN)
A key distinction between bulimia nervosa and anorexia nervosa (AN) is within a term that’s
used: People with AN are “successful” at losing weight (success as in attainment of the person’s
goal – which was to decrease weight – but does not necessarily mean it was adaptive, healthy or
recommended – just that they were successful in achieving their goal). BN is not associated with “success” at losing weight compared to AN (most people with BN are
within 10% of normal weight for height, age, sex)
BN and AN share self-evaluations that are weighted much too heavily on one’s body shape
and/or weight – This is related to the extreme desire to be thin in both disorders.
As we’ll see in the DSM criterial, BN is characterized by having recurrent binges (there are two
criteria for what consists of a binge; see DSM) as well as having recurrent inappropriate
compensatory behaviours (to compensate for having eaten so much food in the binge).
Overall: Binge Compensate
Examples of compensatory behaviours: induced vomiting, laxative abuse, diuretic abuse (makes
you pee), periods of fasting between binges (which aren’t even long enough to cause weight
loss), excessive exercise between binges.
Excessive exercise can include: Exercising to the point of literal exhaustion (i.e. dangerous;
you’re about to lose consciousness), Interferes with important activities/exercising at
inappropriate times (ex. You’re meeting an important friend in the evening but I binge eat in the
morning so I must cancel the meeting so that I can exercise), Exercising despite having a
previously acquired injury/medical complication.
See DSM for BN (slide 27) – Note: Criteria F is referring to the fact that one cannot be
diagnosed with BN or AN at the same time
Bulimia Associated Features
Persistent purging is associated with the following somatic consequences: Dental enamel,
callused (hardened) hands/fingers, salivary gland enlargement, higher body fat, intestinal issues
if laxative use, electrolyte imbalance with laxative or vomiting behaviour (which can lead to an
increased risk of cardiac arrhythmia and renal failure)
Recall the role of compulsions in OCD. In BN, the compensatory behaviours can be thought of
as those compulsions – they tend to reduce the anxiety aroused by binges (I’m worried I’m going
to gain weight). Also recall that compulsions usually have some “magical” connection to the
obsession in that there is no logical reason for the compulsion. In BN, the compensatory
behaviours are illogical because: Vomiting only reduces calorie intake by about half if done very
soon after eating (contrary to the belief that they think all calories get lost). As well, laxatives
and diuretics do virtually nothing to reduce calorie intake.
There is an increasing consideration of anxiety’s role in EDs – BN: anxiety about intake may be
reduced by compensatory behaviours. AN: anxiety associated food intake (or potential intake)
may be reduced by further restriction and sometimes compensatory behaviours (more later).
Bulimia has a high comorbidity with depressive and anxiety disorders (they happen either as a
result of the eating disorder or something else that simultaneously triggers it). A study with a
sample of 20 people with BN had comorbid anxiety disorder but another sample of 20 peop