Cognitive Explanation of Anorexia

Psychological Explanations of Obesity

Whilst biological factors create a strong predisposition to obesity, psychological explanations address the cognitive, emotional, and social mechanisms through which eating behaviour becomes dysregulated — contributing to overconsumption beyond biological need. These explanations are clinically important because they identify modifiable psychological targets for intervention.

Restraint Theory (Herman and Mack, 1975)

Herman and Mack (1975) proposed that chronic dieting produces a paradoxical vulnerability to overconsumption. Restrained eaters — chronic dieters — attempt to eat below their biological hunger signals by imposing a cognitive 'diet boundary'. This cognitive restraint is vulnerable to disinhibition: any event that breaks the perceived diet (eating a forbidden food, consuming alcohol, emotional distress) causes the restraint to collapse entirely — the 'what the hell' effect. Once the perceived dietary boundary has been crossed, the restrained eater ceases to regulate intake and overeats, often substantially. The phenomenon was demonstrated in preloading studies: Herman and Mack (1975) gave participants either a preload (a milkshake — high calorie) or no preload, then offered ice cream and measured consumption. Paradoxically, restrained eaters who had the milkshake consumed more ice cream than those who had no preload — whilst unrestrained eaters consumed less after the preload, as normal satiety regulation would predict. For restrained eaters, the preload 'broke' their diet, triggering disinhibited overeating.

Externality Theory (Schachter, 1968)

Schachter (1968) proposed that overweight individuals are externally controlled — their eating is governed by external cues (time of day, food visibility, palatability, social context) rather than internal hunger and satiety signals. Schachter found that obese participants ate more when food was palatable and visible, but were less influenced by internal hunger signals (food deprivation) compared with normal-weight controls. The externality hypothesis explained why obese individuals might eat based on the clock ('it's lunchtime') rather than hunger, and why food advertising and large portion sizes are particularly problematic for externally controlled eaters. Subsequent research has complicated the picture — externality is not found consistently in all obese individuals, and some externality effects are found in normal-weight people too.

Emotional Eating

Emotional eating refers to the use of food to regulate negative emotional states — eating in response to anxiety, depression, boredom, loneliness, or stress rather than physiological hunger. Van Strien et al. (1986) developed the Dutch Eating Behaviour Questionnaire (DEBQ), which includes an emotional eating subscale. Emotional eaters report increased food consumption when experiencing negative emotions, particularly high-calorie, palatable 'comfort foods'. The mechanism may involve the short-term mood-improving effects of high-carbohydrate, high-fat foods (via serotonin and dopamine release) — these foods provide temporary emotional relief, reinforcing the pattern. Emotional eating is associated with obesity, binge eating disorder, and poorer weight management outcomes.

Social Learning and Environmental Influences

SLT proposes that eating behaviour is modelled from family and social context. Research shows that individuals eat more in social settings (social facilitation of eating), match portion sizes to those eaten by companions, and are influenced by descriptive norms (what people in their social group typically eat). Wansink et al. (2005) demonstrated that people consume significantly more food from larger plates and bowls — the size of the serving container distorts portion size estimation. Food advertising targeting children (Boyland and Halford, 2013) and the ubiquitous availability of large portions of processed food in obesogenic environments contribute to overconsumption through environmental priming rather than deliberate choice.