Obesity, Eating Behaviors, and Physical Activity: Key Theories and Trends

Obesogenic diet

An environment or dietary pattern that promotes obesity through large portions, high sugar/fat foods, processed foods, and a sedentary lifestyle.

Set point theory

The theory that the body has a biologically determined weight range that it actively tries to maintain.

Settling point theory

The theory that body weight settles based on the ongoing interaction between biology, environment, and behavior.

Stress eating gender difference

Women are more likely to overeat for comfort or stress eat, whereas men are more likely to lose their appetite under stress.

Inattention and eating

Distracted eating (such as eating while watching TV) which causes a person to overeat.

Forgetting and eating

Forgetting prior meals or snacks, which inadvertently increases food intake later.

Health Belief Model (Eating)

A model where eating behavior is predicted by perceived susceptibility, severity, benefits, and barriers; perceptions of disease threat (severity + susceptibility) are the MOST predictive.

Theory of Planned Behavior (Eating)

States that attitudes, subjective norms, and perceived behavioral control all interact to produce intentions, which ultimately predict eating behavior.

Social Cognitive Theory (Eating)

States that children learn eating behaviors mainly from observing their mothers, and that self-efficacy influences the amount and type of foods chosen.

Social Networks and Obesity

Obesity can spread through social relationships; an individual is more likely to become obese if their significant others are obese.

US Obesity Trends

The US obesity rate nearly tripled from 1960-2010 to ~35%, giving the US the highest obesity rate among English-speaking countries (14th highest in the world).

Obesity Heritability

Genetic influences supported by twin, adoption, and family studies show that obesity heritability is moderate to high, sitting around 40-70%.

Food Desert

An area characterized by poor access to healthy and affordable foods.

Bariatric Surgery

The MOST effective treatment available for obesity.

Education alone (Obesity)

A treatment method for obesity that is explicitly NOT effective on its own.

Physiological reason diets fail

The body undergoes metabolic adaptation, meaning it lowers its metabolism to adapt to food restriction.

Psychological reason diets fail

Deprivation increases cravings and overeating, often leading to "restraint release" where strict restriction causes a loss of control and binge eating.

Alcohol abuse

A harmful or problematic drinking pattern that includes binge drinking but lacks physiological dependence.

Binge drinking definition

Consuming a large amount of alcohol in a short time (typically ~2 hours); defined as 5+ drinks for men and 4+ drinks for women.

Descriptive norms

Cognitive beliefs regarding what other people actually DO (e.g., beliefs about how much others drink).

Injunctive norms

Cognitive beliefs regarding what other people APPROVE OF (e.g., beliefs about whether others approve of drinking).

Alcohol dependence

Compulsive alcohol use accompanied by physiological indicators like tolerance, withdrawal, and intense craving.

Abuse vs. Dependence

The major difference is that alcohol dependence strictly includes physiological symptoms (tolerance and withdrawal).

Alcoholism Heritability

Supported by twin and adoption studies, the heritability of alcoholism is estimated to be about 50-60%.

Moral model of alcoholism

The belief that alcoholism is a personal weakness or moral failure.

Disease model of alcoholism

The belief that alcoholism is a chronic, biological disease.

Biopsychosocial / Learning model

The model that explains alcoholism as a complex interaction of biology, psychology, and the environment.

Classical conditioning in alcoholism

Learning theory stating that environmental cues and specific settings trigger intense alcohol cravings.

Operant conditioning in alcoholism

Learning theory stating that drinking behavior is reinforced by pleasure or stress reduction.

Brief opportunistic interventions

The MOST effective treatment for alcohol disorders; involves short counseling or advice during regular healthcare visits.

Why alcohol education fails alone

Knowledge does not reliably alter behavior, and social or environmental factors exert a much stronger influence.

Physical activity vs. Exercise

Physical activity is any bodily movement that increases energy expenditure (walking, cleaning); exercise is planned, structured physical activity designed specifically for fitness.

Aerobic exercise

Sustained physical activity that uses oxygen and improves cardiovascular health (e.g., running, swimming).

Anaerobic exercise

Short, intense bursts of physical activity that build strength and muscle (e.g., sprinting, lifting weights).

Physical inactivity

A leading cause of disease worldwide.

Dose response relationship

The principle stating that more physical activity yields greater health benefits, up to a certain point.

SES barriers to exercise

Low SES individuals exercise less because they face barriers like unsafe neighborhoods, less free time, childcare demands, and fewer facilities.

TPB and exercise (Most predictive)

Under the Theory of Planned Behavior, a person's attitudes toward exercise are the most predictive variable of physical activity.

Anticipated regret

A strong predictor of exercise where an individual expects to feel bad if they do not work out.

Beginning exercisers (TTM/SCT)

Individuals focused on overcoming barriers and starting the behavior; they are primarily motivated by extrinsic rewards (appearance, praise, weight loss).

Later stage exercisers (TTM/SCT)

Individuals focused on maintenance and habit where benefits matter more; they are primarily motivated by intrinsic rewards (enjoyment, stress relief, accomplishment).

Built environment

The physical surroundings that influence activity (sidewalks, parks, gyms, bike lanes); a better built environment leads to more exercise.

Contingency contracting

A behavioral agreement featuring specific rewards or consequences tied directly to meeting exercise goals to increase activity through reinforcement.