Untitled Flashcards Set

🔥 Energy Balance Equation

At the core of weight management is the energy balance equation:

Energy In (Calories consumed)=Energy Out (Calories burned)\text{Energy In (Calories consumed)} = \text{Energy Out (Calories burned)}Energy In (Calories consumed)=Energy Out (Calories burned)

Outcomes:

• Positive energy balance: More calories in than out → weight gain

• Negative energy balance: More calories out than in → weight loss

• Energy balance: Calories in = Calories out → weight maintenance

⚙ Components of Energy Expenditure

Your body burns calories in three primary ways:

1. Basal Metabolic Rate (BMR): ~60–75%

• This is the largest portion of your energy expenditure.

• It’s the energy your body uses at rest to keep you alive:

  • Breathing, heartbeat, maintaining body temperature, cell repair

• You burn these calories even if you lie in bed all day.

🔑 Primary determinant of BMR:

• Lean body mass (muscle)

  • The more muscle you have, the more calories you burn at rest.

🔻 Decline in BMR with age:

• Muscle mass decreases with age unless maintained through strength training.

• BMR naturally drops ~1–2% per decade after age 30.

Other factors that affect BMR:

2. Physical Activity (PA): ~15–35%

• The most variable component.

• Includes:

  • Exercise (e.g., jogging, gym workouts)

  • Non-exercise activity thermogenesis (NEAT) – daily movements like fidgeting, chores

3. Thermic Effect of Food (TEF): ~5–10%

• Energy required to digest, absorb, transport, and store nutrients.

• Varies by macronutrient:

  • Protein: Highest TEF

  • Carbs: Moderate

  • Fat: Lowest

4. Adaptive Thermogenesis (very minor)

• Includes involuntary responses like shivering, stress responses.

• Not included in standard calculations but can slightly increase energy expenditure.

🍽 Hunger vs. Appetite

📏 Body Mass Index (BMI)

Formula:

BMI=Weight (kg)Height (m)2orWeight (lb)×703Height (in)2\text{BMI} = \frac{\text{Weight (kg)}}{\text{Height (m)}^2} \quad \text{or} \quad \frac{\text{Weight (lb)} \times 703}{\text{Height (in)}^2}BMI=Height (m)2Weight (kg)​orHeight (in)2Weight (lb)×703​

Classifications:

🚫 Limitations of BMI:

• Doesn’t differentiate between fat and muscle

• Can misclassify:

  • Athletes as overweight

  • Elderly or frail people as normal despite high fat levels

• Doesn’t account for fat distribution

⚖ Body Fat & Body Composition

• Body composition = % of body made up of fat vs. lean tissue

• Essential fat is needed for hormone production, insulation, organ protection

• Too little fat can cause hormone issues and weakened immunity

Measuring body composition:

• Skinfolds

• Bioelectrical Impedance (BIA)

• DEXA scans (most accurate)

• Hydrostatic weighing

🍐 Body Fat Distribution Patterns

1. Upper-body (android/apple shape)

• Fat around abdomen

• More common in males

• Associated with:

  • Higher risk of heart disease, diabetes, and hypertension

2. Lower-body (gynoid/pear shape)

• Fat around hips and thighs

• More common in females

• Lower risk of chronic disease

✅ Components of a Sound Weight Loss Program

1. Slow & steady weight loss: 0.5–2 pounds/week

2. Create caloric deficit of 500–1,000 kcal/day

3. Combine:

   • Healthy diet (nutrient-dense, portion-controlled)

   • Physical activity (cardio + resistance)

   • Behavior changes (goal-setting, self-monitoring)

🇺🇸 Obesity in the U.S.

• Over 42% of U.S. adults are obese.

• Rates have increased over decades due to:

  • Processed food intake

  • Sedentary lifestyle

  • Portion sizes

  • Socioeconomic barriers

🧬 Factors Contributing to Obesity

• Genetics (e.g., low leptin levels)

• Environment (food deserts, sedentary work)

• Psychological (stress, emotional eating)

• Social influences

• Medications

• Sleep deprivation

⚠ Eating Disorders

Anorexia Nervosa

• Self-starvation, extreme fear of weight gain

• Symptoms:

  • Extreme weight loss

  • Amenorrhea (no period)

  • Brittle hair/nails

  • Lanugo (fine hair growth)

  • Cold intolerance

  • Distorted body image

Bulimia Nervosa

• Bingeing large amounts of food, followed by purging

• May involve vomiting, laxatives, or extreme exercise

• Body weight often appears normal

• Important: Purging doesn’t eliminate all calories — absorption starts as soon as you eat

🏃‍♀ RED-S and Female Athlete Triad

RED-S (Relative Energy Deficiency in Sport)

• Occurs when energy intake is too low to support all body functions plus training demands

• Can affect men and women

• Leads to:

  • Fatigue

  • Low endurance

  • Immune problems

  • Bone loss

  • Hormonal imbalances

Female Athlete Triad Components:

1. Low Energy Availability (with or without disordered eating)

2. Menstrual Dysfunction (e.g., missed periods)

3. Low Bone Mineral Density (osteopenia/osteoporosis)

Iron Deficiency

• Iron deficiency is the most common nutrient deficiency globally, especially in developing countries.

• Iron is essential for making hemoglobin, the oxygen-carrying part of red blood cells.

• When iron is low, the body can’t produce enough healthy red blood cells, leading to iron-deficiency anemia.

⚠ Symptoms of Iron Deficiency:

• Fatigue and weakness

• Pale skin or mucous membranes

• Shortness of breath

• Cold hands and feet

• Headache or dizziness

• Poor concentration and learning problems (especially in children)

👥 High-Risk Groups:

1. Women of childbearing age (menstruation increases iron loss)

2. Pregnant women (increased blood volume and fetal needs)

3. Infants and young children (rapid growth, low iron stores at birth)

4. Teenage girls (growth + menstruation)

5. Vegetarians/vegans (non-heme iron only)

6. Low-income populations (less access to iron-rich foods)

🍖 Types of Iron: Heme vs. Non-Heme

📈 Factors that Increase Iron Absorption

• Vitamin C (ascorbic acid) → enhances non-heme iron absorption by converting it to a more absorbable form.

• "MFP factor" → found in meat, fish, poultry; enhances absorption of non-heme iron eaten in the same meal.

• Acidic environment (e.g., stomach acid) helps iron stay soluble.

📉 Factors that Decrease Iron Absorption

• Phytates (in whole grains, legumes)

• Calcium (competes for absorption)

• Polyphenols (in tea, coffee, red wine)

• Oxalates (in spinach, chard)

• Excess zinc or manganese

🧬 Hemochromatosis

• A genetic disorder causing iron overload

• Body absorbs too much iron, even when it doesn’t need it

• Iron builds up in tissues → damages liver, heart, pancreas

• Treatment: Regular phlebotomy (blood removal) and iron-restricted diet

🦋 Iodine and Thyroid Function

• Iodine is essential for making thyroid hormones, which regulate metabolism, growth, and development.

⚠ Iodine Deficiency Conditions:

• Goiter: Enlarged thyroid gland (common where soil lacks iodine)

• Cretinism: Severe birth defects in infants born to iodine-deficient mothers (mental disability, stunted growth)

🛡 Selenium

• Acts as an antioxidant and helps convert thyroid hormones to their active form

• Deficiency: Can lead to Keshan disease (heart condition seen in selenium-deficient areas in China), thyroid dysfunction, and weakened immune function

🦷 Fluoride

• Strengthens tooth enamel, reduces cavities by making teeth more resistant to acid and decay

• Found in fluoridated water, toothpaste, some foods

🚫 Fluoride Toxicity:

• Most common in children from swallowing toothpaste

• Leads to fluorosis: white/brown spots on teeth (mild to severe)

• In large doses: can cause joint pain, stiffness, and bone issues

🧬 Cancer: The 3 Stages

1. Initiation – DNA is mutated by a carcinogen (e.g., tobacco, radiation, alcohol)

2. Promotion – Abnormal cells multiply faster than normal cells

3. Progression – Cancer cells spread, form a tumor, and may metastasize (invade other tissues/organs)

✅ Cancer Prevention: Dietary & Lifestyle Guidelines

• Eat a plant-based diet (fruits, veggies, whole grains)

• Limit red and processed meats

• Avoid tobacco, limit alcohol

• Maintain a healthy weight

• Stay physically active

• Choose foods high in antioxidants, fiber, and phytochemicals

👶 Chapter 16 – Pregnancy Nutrition & Teratogens

☣ Teratogens

• Substances that cause birth defects if a fetus is exposed during pregnancy

• Examples: alcohol, certain drugs, smoking, some infections

🍃 Folate Deficiency

• Folate is essential for neural tube development in the first 28 days of pregnancy

• Deficiency → neural tube defects (e.g., spina bifida, anencephaly)

🔴 Iron During Pregnancy

• Needed for:

  • Making more red blood cells

  • Oxygen transport to fetus

  • Placental and fetal development

• Women are at high risk for anemia during pregnancy

🧲 Pica

• Craving non-food substances (e.g., dirt, clay, ice, starch)

• May signal iron or zinc deficiency

⚖ Weight Gain During Pregnancy

• Based on pre-pregnancy BMI:

  • Underweight: 28–40 lbs

  • Normal: 25–35 lbs

  • Overweight: 15–25 lbs

  • Obese: 11–20 lbs

• Weight gain supports baby, placenta, amniotic fluid, and maternal tissue growth

💉 Gestational Diabetes

• High blood glucose during pregnancy (usually resolves after birth)

• Risks:

  • Large baby (macrosomia)

  • Birth complications

  • Increased maternal/fetal risk of type 2 diabetes later

🍔 Unsafe Foods During Pregnancy

• Listeria risk: unpasteurized dairy, deli meats (unless reheated)

• Mercury: Avoid high-mercury fish (shark, swordfish, king mackerel)

• Raw/undercooked foods: eggs, sushi, meat

• Alcohol: completely avoid → risk of fetal alcohol spectrum disorders

🍼 Breastfeeding Benefits

For Mother:

• Helps uterus return to normal size

• May aid postpartum weight loss

• Delays return of menstruation (natural birth spacing)

• Lowers risk of breast and ovarian cancer

For Infant: (more in Ch. 17)

💛 Colostrum

• First milk (1–3 days postpartum)

• Thick, yellowish fluid rich in:

  • Antibodies

  • Immune cells

  • Growth factors

👶 Chapter 17 – Infant & Child Nutrition

💉 Vitamin K Deficiency Bleeding (VKDB)

• Newborns have low vitamin K (sterile gut)

• Vitamin K is needed for blood clotting

• Given vitamin K injection at birth to prevent bleeding disorders

👶 Breastfeeding Recommendations

• AAP: Exclusive breastfeeding for first 6 months, then continue with complementary foods for 12 months or longer

🥤 Juice & Milk Guidelines

• No juice <12 months

• Limit juice to 4 oz/day (ages 1–3)

• Limit milk to 2–3 cups/day

• Introduce reduced-fat milk at age 2, unless child is overweight

🍽 Solid Foods for Infants

• Start solids around 6 months

• Avoid:

  • Honey (risk of botulism)

  • Cow’s milk (before 1 year)

  • Foods that cause choking: grapes, hot dogs, raw carrots, popcorn, nuts

⚠ Obesity in Children

• Based on percentile of BMI-for-age:

  • Overweight: 85th–94th percentile

  • Obese: ≥95th percentile

🥛 Milk Displacement

• Excess juice or soda displaces milk, reducing calcium and vitamin D intake

• Leads to weaker bones and higher cavity risk

👵 Chapter 18 – Nutrition in Older Adults

👵 Usual vs. Successful Aging

🍽 Nutrient Needs in Older Adults

• Calories: ↓ due to reduced activity and muscle mass

• Protein: ↑ to prevent muscle loss (sarcopenia)

• Fat: moderate intake; focus on healthy fats (e.g., omega-3s)

⚠ At Risk of Malnutrition

• Adults 65+ who are:

  • Isolated or low-income

  • Chronically ill

  • On multiple medications

  • Physically or cognitively impaired

🧓 Nine D’s of Geriatric Weight Loss:

1. Dementia

2. Depression

3. Diarrhea

4. Disease

5. Dentition (poor teeth/dental problems)

6. Dysgeusia (loss of taste)

7. Dysphagia (trouble swallowing)

8. Drugs (side effects)

9. Dysfunction (physical disability)