2_Harmful Eating Behaviors.pdf

Harmful Eating Behaviors The Social Science of Food and Eating • Eating is a highly motivated and reinforced behavior (drive theory) • Food and eating often have central sociocultural significance (e.g., Mintz & Du Bois, 2002) • Many cultural rituals around food and eating, and culturally importa...

Harmful Eating Behaviors The Social Science of Food and Eating • Eating is a highly motivated and reinforced behavior (drive theory) • Food and eating often have central sociocultural significance (e.g., Mintz & Du Bois, 2002) • Many cultural rituals around food and eating, and culturally important events often prominently feature food and eating • Sharing of food plays an important role in social bonding/affiliation in humans and many non-human animals • There have been huge shifts over time and across cultures in the availability of food; the particular foods we eat; and attitudes toward food, eating, and weight Body Dissatisfaction & Weight Stigma • In one study of middle and high school students (N • Common narratives understate factors outside of = 4,746), 41.5% of girls and 24.9% of boys reported people’s direct control (e.g., genetics, homeostatic problems with body image (Ackard et al., 2007) regulatory mechanisms, social and structural • > 1/3 of girls and ~1/4 of boys said they placed a lot of importance on weight and shape with regard to self-esteem • Weight one of the most common reason for school bullying (Puhl & King, 2013) • Society strongly emphasizes bodily appearance in general and purported role of personal (eating) choices/habits in appearance/weight, specifically determinants) on weight and overstate strength of the relationship between weight/BMI and health • Even the AMA has begun to disavow BMI as a measure of individual health! Clinical Description & Epidemiology of Harmful Eating Behaviors “I am forever engaged in a silent battle in my head over whether or not to lift the fork to my mouth, and when I talk myself into doing so, I taste only shame. I have an eating disorder.” – Jena Morrow, Hollow The only number that would ever be enough is 0. Zero pounds, zero life, size zero, double-zero, zero point.” Marya Hornbacher, Wasted Common Characteristics of Eating Disorders in the DSM-5 Nervosa = “the psychological addiction to a behavior, belief, or habit that effects the body via the nervous system, or the mind” DSM-5 Criteria for AN DSM-5 Criteria for AN • Some people with AN may not be overtly distressed either by the restricted eating or by the weight loss • Can be a point of personal satisfaction, pride • May be ambivalent (e.g., some people with AN who are very thin take steps to conceal this from others) • Contrary to popular belief, stereotypic media depictions, and the DSM criteria, it is possible to both be overweight and have the core symptoms of AN (‘“atypical” anorexia’) • “Atypical anorexia” is not uncommon and is associated with similar harms (Walsh et al., 2023) • Underdiagnosis, delays in treatment for people with EDs who are overweight Binges in BN • Common to have 1-30 binges/week • Consume an average of 2000-3400 calories (but can be in excess of 10000) • Often focused on “highly palatable foods” (e.g., calorie dense, especially sweet or salty) • Often described as “mindless” (food is hardly tasted or thought about) • Often preceded by increased stress, tension, anxiety • Binges may temporarily relieve these feelings (functionalist model) • But often followed by self-blame, disgust, shame, guilt, fears of gaining weight • Binges and compensatory behavior often carried out in secret Compensatory Behavior • Various behaviors to “undo” (“compensate for”) binges • Purging behaviors may be most common, but other behaviors are common as well • Many such behaviors don’t actually fully undo the caloric effects of bingeing (Mitchell, 2016) • And they can have ironic consequences (e.g., repeated vomiting affects one’s ability to feel satiated, which leads to greater hunger and more frequent and intense binges in the long run) DSM-5 Criteria for BED • New addition as of DSM-5 • Recognition that there is a large subset of folks who engage in frequent binging that is associated with distress and/or impairment, but not in compensatory behaviors or restriction • Has been argued that BED may be essentially a less severe form of BN? Diagnostic Crossover • Very common for someone who meets criteria for one form of eating disorder to later meet criteria for another eating disorder • For example, over a 7-year period, Eddy et al. (2008) reported that the majority of participants in their study (all women) experienced “diagnostic crossover” • Not surprising given how much overlap there is in the criteria (e.g., all three can involve binge eating) • Does this undermine the validity of the current categories? • Some have argued for a more dimensional approach Epidemiology • AN: lifetime prevalence: < 1% in the US; gender ratio: 3+:1; average onset: 14-20 • BN: lifetime prevalence: ~1% worldwide; gender gap as large or maybe even larger than for AN; average onset: 15-24 • BED: lifetime prevalence: ~2% worldwide; more common in women, but gender gap less stark; slightly later average age of onset • Many others engage in subclinical forms of disordered eating (e.g., 40+% of high-school aged girls and 30+% of high-school aged boys, depending on definition/measure/sample) • Associated with increased risk for eating disorders + negative consequences in their own right • Rates vary significantly across countries • Frequently comorbid with other mental disorders (e.g., depression, OCD, personality, etc.) Physical Changes in AN • Although many of these problems resolve if people stop restricting, some changes are more persistent (e.g., reduced bone density in later life for young adults with AN) • AN is one of the most directly medically dangerous diagnoses in the DSM • Restriction of food can result in serious health problems, potentially fatal organ damage • Mortality rates are 5-10x higher than the general population • Mortality rates 2x higher than other psychological disorders • 3-6% become so ill that they die Physical Changes in BN • Menstrual irregularity (amenorrhea) • Compensatory behaviors can be harmful • Potassium, electrolyte depletion can lead to kidney or heart damage • Loss of dental enamel from stomach acids • Mortality rate is 2x that of people of comparable age in the general population Physical Changes in BED • Weight gain (but important to know that binge eating is not the primary driver of obesity from a public health standpoint) • Can drive development of body-related dissatisfaction, elicit stigma, which can result in more intensely disordered eating behaviors, including crossover to BN • Type 2 diabetes • Cardiovascular risk Prognosis for AN • 50-75% eventually recover • But can take a long time (6-7 years) • Relapse common • More difficult to modify distorted view of self—especially in cultures that highly value thinness—than to modify behavior • Body dissatisfaction often persists • High rate of suicide (5-18x the general population) Prognosis for BN • ~75% recover • 10-20% remain chronically, syndromally symptomatic • Early intervention associated with improved outcomes • Poorer prognosis when depression, SUDs are comorbid • Poorer prognosis when more severe symptomatology • Suicide attempts are made in 25-30% of cases (Franko & Keel, 2006) Prognosis for BED • Less research – estimates of recovery range from 25-82% (!!) • Average duration of just over 4 years (Kessler et al., 2013) Risk Factors & Causal Models Genetics • Twin studies indicate that AN and BN are heritable (not many studies of BED) • Haven’t been many adoption studies, but also consistent with heritability (Klump et al., 2010) • Relatives of those with eating disorders are also at greater risk for major depression, substance use disorders, OCD (recall that many risk factors are non-specific) • Findings from one large international GWAS found strong genetic overlap with genetics of OCD, schizophrenia, negative affectivity, metabolic factors (Duncan et al., 2017) • No convincing findings from candidate gene studies (Root et al., 2011) • Evidence that body dissatisfaction, desire for thinness, binge eating, and weight preoccupation are all partially heritable – but mechanisms/mediators not clear Neurobiological Factors • Some evidence of overlapping neurobiology with generalized anxiety, OCD, depression – cause, effect, or neither? • Could reflect comorbidities • Not clear that the hypothalamus is directly involved despite key roles in appetite, satiety, regulation of weight • Low levels of endogenous opioids (endorphins)? • Substances that reduce pain, enhance mood, suppress appetite • Food deprivation, intense exercise can trigger release → reinforce restricted eating, compulsive exercise seen in AN • In BN, some evidence that low levels of beta-endorphins promote craving → bingeing Neurobiological Factors • Serotonin related to feelings of satiety (feeling full) • Some evidence of low levels of serotonin metabolites in AN • May be partly a consequence of malnutrition (most serotonin synthesis occurs in the gut, tryptophan an important precursor of serotonin) • Movement away from our body’s biologically grounded weight set point → increased hunger → eating binges • Replicability of alleged neurobiological risk factors has been called into question Cognition in AN • Body dissatisfaction, preoccupation with thinness • Tendency to overestimate body size • Self-esteem tied to evaluation of + control over body • Perception of self as unattractive + inadequate • Fear of fatness, “giving in” to desire to eat, losing control • May interact with generally heightened sensitivity of fear systems (e.g., Frank, 2014) • Perfectionism • (Perceived) lack of control over life (taking back control by controlling body?) • Preoccupation with food, eating (may be partly result of food restriction) “I look in a full-length mirror at least four or five times daily and I really cannot see myself as too thin. Sometimes after several days of strict dieting, I feel that my shape is tolerable, but most of the time, odd as it may seem, I look in the mirror and believe that I am too fat.” (Bruch, 1973) Behavior: Patterns of Reinforcement • Restricted eating, excessive exercise, binges, compensatory behaviors can temporarily alleviate negative emotions (negatively reinforcing) • Difficulties with emotion regulation associated with eating disorders • But, binges → shame, guilt, and self-directed anger → binges • Restricting eating, weight loss can enhance feelings of self-control, self-efficacy, self-worth (positively reinforcing) (Wang et al., 2022) • People may receive praise for restricting their eating, losing weight (positively reinforcing) vs. criticism when they gain weight (punishing) • We often see alterations of biological reward, motivation, and salience systems (e.g., greater sensitivity to thinness cues in AN; e.g., O’Hara et al., 2015) Family Characteristics & Early Life Experiences • High levels of family conflict, low levels of family support • Not specific to eating disorders • Weight/eating can be a common subject of criticism + conflict, so disordered eating may precede parent-child conflict in some cases (Spanos et al., 2010) • Self-report studies have found high rates of childhood sexual and physical abuse – again, not really specific to eating disorders • Modeling of dieting, emphasizing thinness and appearance Sociocultural Factors • Ideal body image has changed over time, differs across cultures • Unrealistic media portrayals of bodies • • Higher exposure to Western media → more body dissatisfaction (e.g., Swami et al., 2010) Intense and pervasive weight stigma • Lots of evidence that this leads to more disordered eating, weight gain, poor physical and mental health – likely through multiple mechanisms, include direct biological effects of stress • Diet culture: at any given time, ~39% of women report they are trying to lose weight • Most young girls have tried dieting at least once before age 10 (!!!) • Popular TikTok videos glorify weight loss, thinness (Minadeo & Pope, 2022); existence of online communities that promote disordered eating behaviors (e.g., Rogers et al., 2012) • • Common elements of diets include restriction, intense attention on eating behaviors and changes in weight • Socially condoned forms of dieting often precede onset of eating disorders (and aren’t particularly effective for losing weight!) Access to large quantities of highly palatable foods (Keel, 2010), but also poverty + food insecurity (Becker et al., 2017) Gender • Objectification, evaluation, policing of women’s bodies • Thinness emphasized more for women than for men • Societal objectification can be internalized • Objectification → shame → restricted eating (Frederickson et al., 1998) • Gender bias in research, DSM criteria, media portrayals • Biases likely contribute to underdiagnosis/misdiagnosis of eating disorders in men • Men also less likely to receive specialist treatment Treatment Treatment • Most don’t receive treatment (~30-44% receipt) • Men, people with higher BMIs less likely to receive treatment • People with eating disorders often pessimistic about potential for recovery (e.g., Holliday et al., 2005) • Not enough providers with expertise, specialization in eating disorders • In (severe) AN, immediate goal may be stabilizing and/or increasing weight to address acute health concerns (nutritional rehabilitation) • In particularly severe cases, may be in-patient, involve IV nutrition • ~15 percent of patients with severe eating disorders are committed to a hospital for treatment against their will (Watson, Bowers, & Andersen, 2000) • Not a substitute for treatment aimed at reducing harmful eating behaviors in the long-run • Clinical practice guidelines generally emphasize eating disorder-focused psychotherapy (or, in some cases, psychotherapy + medication) > medication Cognitive Behavioral Therapy • Challenge societal ideals of thinness; beliefs about food, dieting, and weight • Enhance interpersonal skills (e.g., assertiveness) • Regularize eating patterns • Some evidence that adding ERP can increase efficacy of CBT, at least in the short term • Recommended length of treatment for AN is 1-2 years • High intensity, individual treatment is recommended (Kaidesoja, Cooper, & Fordham, 2022) • Even intensive residential programs can last 6+ months (and can be super-duper expensive!) • Strong evidence of reductions in symptoms through one year, but not enough long-term outcome research Family-Based Therapy (FBT) for AN • Anorexia viewed as an interpersonal (vs. individual) problem • But neither the parent nor the child is blamed • Family works together as a team to support change (e.g., “family lunch” sessions), guided by a therapist • Beyond eating: Establishing new patterns of relationships, interactions; addressing issues in the family system (e.g., conflict resolution) • Some evidence that FBT may be more effective than individual therapy • 5 years after treatment, 75-90% showed full recovery (le Grange & Lock, 2005) Medication • Antidepressants can be helpful for some with BN (e.g., can reduce binges, body preoccupation, improve mood) • Some evidence they may be effective for BED as well (see Aigner et al., 2011); no strong evidence they are effective for AN • Seemingly less effective than CBT, though • Some evidence that olanzapine (an antipsychotic) can be beneficial in AN • Weight gain is a common “side effect” • Vyvanse (more familiar as an ADHD med) approved for the treatment of BED in 2018 • Decreased appetite is a common “side effect” • Overall, not clear that therapy + medication > therapy (Reas & Grilo, 2021) • As elsewhere, efforts to develop and evaluate novel pharmacotherapies Prevention • Psychoeducational approaches (e.g., early education about the dangers of eating disorders) • Efforts to confront and de-emphasize unrealistic beauty standards, diet culture, etc. (e.g., Eric Stice & Carolyn Black Becker’s work on The Body Project) • Various social movements: body positivity, body neutrality, health-at-all-sizes, etc. (note: not much systematic evaluation of effects of these movements on disordered eating behaviors) • Universal prevention vs. risk-factor approach Research on eating disorders is dramatically underfunded and too often treated as a “niche” topic