characterizedofcharacterized by abnormally low sodium levels in the blood, often due to excessive water intake that dilutesMinerals and Water

Water

Water is an essential nutrient that plays a vital role in maintaining physiological balance and supporting life processes.

• Fluid Balance: Water helps regulate the distribution of fluids inside and outside cells, maintaining homeostasis.

• Electrolytes: Electrolytes are minerals (such as sodium, potassium, and chloride) that carry an electrical charge when dissolved in body fluids. They are crucial for fluid balance, nerve transmission, and muscle contraction.

• Dehydration: Occurs when water loss exceeds intake, leading to symptoms such as thirst, dry mouth, reduced urine output, fatigue, dizziness, and headache. Causes include insufficient fluid intake, excessive sweating, vomiting, diarrhea, and fever.

• Hyponatremia: A condition , and bloodof abnormally low sodium levels in the blood, often due to excessive water intake diluting sodium concentration.

Functions of Water:

• Temperature Regulation: Water's high heat capacity allows it to absorb and release heat slowly, stabilizing body temperature. Sweating and evaporation help cool the body.

• Nutrient Transport: Water transports nutrients and oxygen to cells.

• Waste Removal: Facilitates excretion of metabolic waste via urine and feces.

• Lubrication: Acts as a lubricant for joints and tissues.

• Medium for Chemical Reactions: Serves as a solvent for biochemical reactions.

Minerals

Minerals are inorganic nutrients required in small amounts for various physiological functions.

• Calcium (Ca):

  • Functions: Bone and tooth structure, muscle contraction, nerve function, blood clotting.

  • Sources: Dairy products, leafy greens (kale, broccoli), fortified foods.

  • Deficiency: Leads to weakened bones; risk of osteoporosis (low bone density, increased fracture risk).

  • Osteoporosis Risk Factors: Age, female sex, low body weight, family history, certain medications, poor diet.

  • Prevention: Adequate calcium and vitamin D, weight-bearing exercise, avoid smoking/excess alcohol.

• Iron (Fe):

  • Functions: Component of hemoglobin (oxygen transport in blood), myoglobin (oxygen storage in muscle), energy metabolism.

  • Sources: Red meat, poultry, fish, beans, lentils, fortified cereals.

  • Deficiency: Causes iron-deficiency anemia (fatigue, weakness, pale skin, shortness of breath, dizziness).

• Iodine (I):

  • Role: Essential for thyroid hormone synthesis (thyroxine, triiodothyronine), which regulate metabolism.

  • Deficiency: Can cause goiter, hypothyroidism, and impaired cognitive development (cretinism in children).

• Fluoride (F):

  • Role: Incorporated into tooth enamel, it increases resistance to acid and reduces cavities.

• Magnesium (Mg):

  • Functions: Cofactor in 300+ enzyme reactions, energy production, protein synthesis, muscle/nerve function, blood glucose control, blood pressure regulation.

  • Muscle Function: Essential for muscle relaxation.

• Sodium (Na):

  • Function: Major electrolyte for fluid balance and nerve impulse transmission.

  • Blood Pressure: High sodium intake can increase blood pressure.

  • Hyponatremia: Can result from excessive water intake, diluting sodium levels.

Weight Management and Energy Balance

Weight Assessment

Assessing body weight and composition is important for evaluating health risks.

• Body Mass Index (BMI): Estimates body fat based on weight and height.

BMI Formulas:

• Metric:

• Imperial:

BMI Categories:

• Underweight: < 18.5

• Healthy Weight: 18.5 – 24.9

• Overweight: 25.0 – 29.9

• Obesity: ≥ 30

• Waist Circumference: Measures abdominal fat; high values indicate increased health risk due to visceral fat (fat around organs).

• Limitations of BMI: Does not distinguish between fat and muscle; may misclassify athletes or older adults.

Energy Balance

Energy balance is the relationship between calories consumed and calories expended.

• Positive Energy Balance: Intake > expenditure; leads to weight gain.

• Negative Energy Balance: Expenditure > intake; leads to weight loss.

• Weight Maintenance: Intake equals expenditure.

Components of Energy Expenditure

• Basal Metabolic Rate (BMR): Energy needed for basic life functions at rest (breathing, circulation, cell production). Largest component of daily energy expenditure.

• Thermic Effect of Food (TEF): Energy used to digest, absorb, and metabolize food.

• Physical Activity: Energy expended during movement and exercise.

Healthy Weight Management

• Realistic Goals: Aim for gradual weight loss (1-2 pounds per week).

• Healthy Behaviors: Sustainable changes in diet and activity.

• Benefits of Physical Activity: Weight management, improved cardiovascular health, increased muscle/bone density, reduced chronic disease risk, improved mood.

• Long-Term Change: Sustainable habits are key for lasting weight management.

• Satiety: Feeling of fullness after eating. Strategies to increase satiety include fiber-rich foods (fruits, vegetables, whole grains, legumes) and balanced meals with protein, healthy fats, and complex carbs.

• Calorie-Pound Relationship: Approximately 3,500 calories = 1 pound of body fat. To lose 1 pound per week, a deficit of 500 calories per day is needed.

Obesity

• Risk Factors: Genetics, environment, diet, inactivity, socioeconomic and psychological factors.

• Health Consequences: Type 2 diabetes, hypertension, cardiovascular disease, certain cancers, sleep apnea, osteoarthritis.

Bariatric Surgery

• Eligibility: BMI ≥ 40, or BMI ≥ 35 with significant obesity-related health problems, and unsuccessful with other weight-loss methods.

• Purpose: Reduces stomach size or alters digestive tract to limit intake/absorption.

• Recommendation: Used with lifestyle changes for severe obesity and health risks.

Eating Disorders

• Anorexia Nervosa: Intense fear of weight gain, distorted body image, severe food restriction, significantly low body weight.

• Bulimia Nervosa: Recurrent binge eating with compensatory behaviors (vomiting, excessive exercise, laxatives, fasting).

• Binge Eating Disorder (BED): Recurrent binge eating without regular compensatory behaviors; feelings of guilt, depression after episodes.

• Other Specified Feeding or Eating Disorders (OSFED): Disorders causing distress/impairment but not meeting full criteria for above disorders.

• Risk Factors: Dieting history, body dissatisfaction, social pressures, genetics, psychological factors (low self-esteem, perfectionism, anxiety).

Food Safety and Technology

Foodborne Illness

Foodborne illness results from consuming contaminated food, often due to bacteria, viruses, parasites, or toxins.

• Symptoms: Nausea, vomiting, diarrhea, abdominal cramps, fever.

• Prevention: Proper food handling, cooking, and storage.

High-Risk Populations: Older adults, infants/young children, pregnant women, immunocompromised individuals.

Foodborne Pathogens

• Salmonella: Found in raw/undercooked poultry, eggs, meat, unpasteurized milk/juices, contaminated produce.

• E. coli O157:H7: Found in undercooked ground beef, unpasteurized milk/juices, raw sprouts, contaminated water.

• Botulism (Clostridium botulinum): Associated with improperly canned foods, fermented foods, baked potatoes in foil. The anaerobic environment allows toxin production.

Food Safety: The Core Four Principles

• Clean: Wash hands and surfaces often (at least 20 seconds with soap and warm water).

• Separate: Prevent cross-contamination by using separate cutting boards/utensils for raw meats and produce.

• Cook: Cook foods to safe internal temperatures (e.g., poultry: 165°F, ground meats: 160°F).

• Chill: Refrigerate perishable foods within 2 hours (1 hour if above 90°F); keep refrigerator at 40°F or below, freezer at 0°F or below.

Cross-Contamination

• Definition: Transfer of harmful bacteria from one food/surface to another.

• Prevention: Handwashing, separate utensils, cleaning surfaces, proper storage (raw foods below ready-to-eat foods).

Handwashing

• Procedure: Wet hands, apply soap, lather and scrub all surfaces for at least 20 seconds, rinse, dry with clean towel or air dry.

Temperature Safety

• Temperature Danger Zone: 40°F to 140°F; bacteria multiply rapidly in this range.

• Proper Refrigerator Temperature: 40°F or below.

• Safe Thawing: In refrigerator, cold water (change every 30 min), or microwave. Never thaw at room temperature.

Food Processing

• Pasteurization: Heating foods to a specific temperature for a set time to kill harmful microorganisms, reducing illness risk and extending shelf life.

Food Additives

Food Storage

• Refrigeration: Keep at 40°F or below; store raw meats below ready-to-eat foods.

• Leftovers: Refrigerate within 2 hours; reheat to 165°F.

• Safe Thawing: Refrigerator, cold water, or microwave.

Special Populations: Pregnant Women

• Foods to Avoid: Unpasteurized cheeses, raw/undercooked meat, poultry, seafood, eggs, deli meats/hot dogs (unless steaming hot), certain raw sprouts, high-mercury fish (shark, swordfish, king mackerel, tilefish), unpasteurized juices/cider, alcohol.