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Lifetime % of U.S. population with an eating disorder

About 9%

% of people with disordered eating who progress to a clinical eating disorder

20–30%

When do eating disorders typically begin?

Adolescence and young adulthood; triggered by trauma, stress, or events like post-COVID (15–20% spike in cases)

Types of clinical eating disorders

Anorexia nervosa (restricting & binge-purge subtypes), bulimia nervosa, OSFED

OSFED

Other Specified Feeding or Eating Disorder; examples: orthorexia nervosa, diabulimia, ARFID

Anorexia nervosa – characteristics

Severe restriction to <85% of expected body weight, intense fear of weight gain, distorted body image; subtypes: restricting and binge-purge

Bulimia nervosa – treatment

CBT to break the binge-purge cycle, establishing regular eating, SSRIs

Orthorexia nervosa

OSFED; obsession with "pure"/"healthy" eating and rigid food rules. Consequences: nutrient deficiencies, social isolation, guilt. Treatment: CBT + nutritional rehabilitation

Diabulimia

OSFED; skipping insulin in Type 1 diabetes to lose weight. Consequences: high A1C, DKA, organ damage, blindness, 3x the mortality risk of T1D alone. Treatment: diabetes management + eating behaviors

ARFID

Avoidant/restrictive food intake disorder; restriction due to sensory issues, low appetite, or aversions (no body image fear); common in children and autism spectrum. Consequences: weight loss, nutrient deficits. Treatment: nutritional rehab + behavioral approaches

Types of disordered eating conditions

Binge-eating disorder (BED), night-eating syndrome, chronic dieting, RED-S

BED – characteristics

Recurrent binges (at least once a week for 3 months) with distress but no regular purging

BED – consequences & treatment

Obesity, metabolic syndrome, Type 2 diabetes, anxiety, low self-esteem. Treatment: CBT and regular eating habits

Night-eating syndrome

At least 25% of daily calories eaten after the evening meal, disrupting sleep. Consequences: obesity, heart disease, T2D, sleep apnea, stroke, arthritis. Treatment addresses eating, sleep, and mood

Chronic dieting

Obsession with calories, "good/bad" food labels, strict diets, excessive exercise, negative body image. Consequences: nutrient deficiencies, slowed metabolism, irritability, poor focus; 25% risk of progressing to an ED. Treatment: intuitive eating

RED-S

Relative Energy Deficiency in Sport; disordered eating, menstrual dysfunction, low bone density in athletes. Replaces the Female Athlete Triad. Treatment: restore energy balance via multidisciplinary care

"Eating disorders occur along a continuum"

Eating behaviors exist on a spectrum from normal to severe clinical conditions; 20–30% with disordered eating progress to a diagnosable ED

Disordered eating vs. clinical eating disorder

Disordered eating: unhealthy habits that don't fully meet DSM-5 criteria but can still cause harm. Clinical ED: DSM-5 psychiatric condition with severe disturbances; requires professional diagnosis; higher mortality

Genetic/biological factors in eating disorders

50–80% heritability; 4–10x higher risk with family history; serotonin/dopamine imbalances; gut-brain axis

Family dynamics and eating disorders

Rigid households linked to anorexia; chaotic households linked to bulimia

Sociocultural/media influences on eating disorders

Glorification of thinness; social media driving body dissatisfaction (30% rise 2020–2025)

Personality traits and eating disorders

Perfectionism & anxiety → anorexia; impulsivity & low self-esteem → bulimia; combined with triggers like trauma or stress

Steps for discussing an eating disorder with a friend/family member

Approach with care and non-judgmental concern, express support, encourage professional help (physician, RD, therapist), offer to connect them to resources; family involvement (e.g., FBT) is crucial

Female athlete triad – 3 components

Disordered eating (low energy availability), menstrual dysfunction, low bone density

How the female athlete triad components are interconnected

Low energy availability disrupts hormones → menstrual irregularities → reduced bone density and osteoporosis risk

Ways to prevent eating disorders

Reduce weight stigma, media literacy, balanced eating & activity, intuitive eating, body-positivity programs (cut risk 50%), SCOFF screening, school nutrition education, monitoring athletes/diabetics; early intervention prevents up to 30% of cases

SCOFF questionnaire

Screening tool for early detection of eating disorders

Benefits of physical activity

Stronger heart, better mood & energy, lower chronic disease risk (T2D, hypertension, obesity, heart disease), healthy weight, better sleep, quality of life, athletic performance

Physical activity

Any movement that uses energy (e.g., walking to class, gardening)

Exercise

Planned, repetitive, structured activity aimed at improving fitness (e.g., jogging, weightlifting)

Physical fitness

The body's resulting ability to perform tasks efficiently

Hypertrophy

Muscle growth from strength training

Atrophy

Muscle loss from disuse or inadequate nutrition

Why does a high-carb diet increase endurance?

Maximizes muscle and liver glycogen, the primary fuel for high-intensity and prolonged activity; delays fatigue ("bonking")

Recommended carbohydrate intake

6 g/kg body weight daily; 7–10 g/kg for endurance athletes

Glycogen use during activity

Fuels high-intensity efforts and the early stages of moderate activity

Fat use during activity

Largest energy reserve; dominant fuel (>50%) in longer, lower-intensity exercise

Protein use during activity

Minimal: ~5% at rest, up to 15% in endurance (via branched-chain amino acids)

Carbohydrate loading

Maximizes glycogen for endurance events >90 minutes; taper exercise while eating 7–10 g/kg carbs daily; boosts stores 50–85%, delays fatigue

Average daily fluid needs

About 9 cups (women), 13 cups (men)

Fluid intake before exercise

Drink freely 24 hours before; 5–7 ml/kg four hours prior

Fluid intake during & after exercise

1.5–3.5 cups per hour during long events; 2–3 cups per pound lost afterward; avoid losing >2% body weight

When are sports drinks preferred over water?

Workouts longer than 60 minutes — they provide carbs (blood glucose) and electrolytes; water is enough for shorter sessions

Hyponatremia

Low blood sodium from overhydration, esp. during low-intensity activity. Symptoms: confusion, seizures. At risk: people who gain weight during exercise or over-drink plain water. Prevent: sports drinks for long events, monitor intake

FITT principle

Frequency, Intensity, Time, Type — used to design balanced fitness programs, ensure progression, and reduce injury (e.g., 5 days/wk, moderate, 30 min, brisk walking)

Muscular strength

Maximum force a muscle can exert (e.g., one heavy lift)

Muscular endurance

Ability to repeat efforts (e.g., multiple push-ups)

Muscular power

Strength combined with speed (e.g., jumping)

Why is goal setting important for exercise?

Provides motivation and focus; break long-term goals into smaller, measurable, realistic steps; track progress and adjust

Anaerobic vs. aerobic ATP yield from glucose

Anaerobic: 2 ATP per glucose — fast but inefficient, lactate buildup (sprints). Aerobic: far more ATP (guide: "up to 95% of possible ATP"), sustainable for hours

Ergogenic aid

Substance or method that enhances athletic performance (e.g., carbs, water, electrolytes, creatine)

Creatine

Increases phosphocreatine stores for short, intense bursts; effective in power/strength sports

Carbohydrate gels/bars

Ergogenic aid that sustains energy during endurance events

Functional roles of micronutrients

Assist body functions like energy metabolism and maintaining healthy cells/tissues; needed in small amounts; lower absorption (3–10%) than macronutrients

Vitamins vs. minerals

Vitamins: organic (carbon-containing). Minerals: inorganic; cannot be synthesized by plants or animals

Do vitamins or minerals provide calories?

Neither — only macronutrients (carbs, fat, protein) provide energy

Fat-soluble vitamins

A, D, E, K — stored in liver and fat tissue, toxicity possible, deficiency develops slowly (months), multiple chemical forms

Water-soluble vitamins

C and B vitamins — minimal storage, toxicity rare, deficiency appears quickly, excess excreted in urine

How many vitamins are essential?

All 13

Megadose concerns

Easier to reach toxic levels with supplements than food; may harm certain groups, alter nutrient balance, lack whole-food benefits (phytochemicals); a varied diet is preferred

Fat- vs. water-soluble vitamins: absorption, transport, storage

Fat-soluble: absorbed with dietary fat, stored extensively (liver/adipose) → toxicity risk, slow-onset deficiency. Water-soluble: readily absorbed, minimal storage, excreted in urine → rapid-onset deficiency if intake is low

Major minerals

7 minerals required at ≥100 mg/day (e.g., calcium, phosphorus, magnesium)

Trace minerals

8 minerals required at <100 mg/day; body contains <5 g total (e.g., iron, zinc, selenium, chromium)

Athletes and micronutrient needs

May need the same or slightly more due to higher calorie intake (B vitamins, C, E, iron, calcium); emphasis on a varied diet

Nutritional bioavailability

How much of a nutrient is absorbed and used; depends on chemical form, binders in food, and other nutrients in the meal

Heme vs. non-heme iron absorption

Heme (meat, fish, poultry) ~25% absorbed; non-heme (plants) ~3–5%

Role of B vitamins as coenzymes

Help convert carbs, fat, and protein into ATP; support red blood cell health

Enzyme vs. coenzyme vs. cofactor

Enzyme: protein that speeds up reactions. Coenzyme: organic helper molecule (often a B vitamin). Cofactor: inorganic helper (often a mineral)

Phytochemicals

Plant compounds that provide health benefits beyond basic nutrition; supplied by a variety of foods (not supplements)

Functional food vs. fortified food

Functional: provides benefits beyond basic nutrition (e.g., yogurt with probiotics). Fortified: nutrients added (e.g., vitamin D–fortified milk)

Nutrient–disease risk associations

Vit C–cataracts; Vit D–colon cancer; Vit E–diabetes complications; Vit K–osteoporosis; calcium–hypertension; chromium–T2D in older adults; magnesium–muscle wasting in older adults; selenium–certain cancers

Vitamins C and E – main function

Antioxidants that protect cells from exercise-induced oxidative stress

Vitamin A and selenium

Linked to disease prevention (selenium with certain cancers)

Antioxidant requirements & toxicity

Met through diet; athletes may need slightly more; toxicity more likely from supplements than food

Food sources of antioxidants (C and E)

Fruits, vegetables, and whole grains; a varied diet provides all

Xerophthalmia

Spectrum of eye problems from severe vitamin A deficiency; leading cause of preventable childhood blindness

Does excess beta-carotene cause toxicity?

No — causes carotenemia (harmless yellow-orange skin, esp. palms/soles); the body tightly regulates conversion to active vitamin A

How vitamin E works as an antioxidant

Lipid-soluble, chain-breaking antioxidant; scavenges free radicals and prevents lipid oxidation in the membrane bilayer, protecting cell membranes, lungs, and red blood cells

Vitamin C and colds

Doesn't prevent colds in the general population; may reduce duration/severity ~8–14%; stronger benefit under severe physical stress (athletes, soldiers)

Antioxidant

Substance that protects cells from oxidative damage caused by free radicals and exercise-induced stress

Oxidation and reduction (redox) reactions

Reactions involving the transfer of electrons; antioxidants help manage them to prevent cellular damage

Acronym for redox reactions

OIL RIG — Oxidation Is Loss, Reduction Is Gain (of electrons)

Antioxidants, phytochemicals, and cancer

Plant-rich diets with antioxidants (C, E) and phytochemicals are associated with decreased risk of certain cancers; selenium specifically linked

Are vitamin/mineral supplements worth taking?

Controversial; a varied diet usually meets needs and adds phytochemicals & better mineral absorption; supplements raise toxicity risk and alter nutrient balance; athletes may benefit if intake is inadequate, but food-first is preferred

DSHEA

Dietary Supplement Health and Education Act (1994): defines supplements as a food category; manufacturers responsible for safety & accurate labeling before marketing; prohibits adulterated/misbranded products; distinguishes supplements from food additives and drugs