Untitled Quiz

Human Nutrition: Introduction to Nutrition

• Nutrition is the science of foods, nutrients, and other substances within the body. This includes ingestion, digestion, absorption, transport, metabolism, and excretion.
• Nutrition is based on the food requirements of humans for energy, growth, maintenance, reproduction, and lactation.
• Foods are products derived from plants or animals that provide energy and nutrients for life.
• A diet is the sum of all foods and beverages a person consumes.
• The science of nutrition is the study of nutrients and other substances in food and how the body processes them. It draws on biology, biochemistry, and physiology.
• Nutrients are chemical substances obtained from food used for energy, structuring materials, and regulating agents. They support the growth, maintenance, and repair of tissues, and may reduce the risk of certain diseases.

Definitions

• Foods: Plant and animal products taken into the body for energy and nutrient maintenance and tissue repair.
• Diet: The foods and beverages a person eats and drinks.
• Science of Nutrition: The study of nutrients and other substances in foods, and the body's mechanisms for handling them.

Nutrients

• Nutrients are chemical substances from food used for energy, structural materials, and regulating agents in the body. They promote growth, maintenance, and tissue repair, and potentially reduce the risk of disease.

Major Groups of Foods

• Nutrients categorize foods into: carbohydrates, protein, fat, vitamins, minerals and water.

Nutrients: Essential or Nonessential

• Essential Nutrients: The body cannot create enough of these nutrients for bodily functions and needs to be obtained from food. There are about 40 essential nutrients for humans. Water is the most important one.
• Nonessential Nutrients: The body can produce these nutrients in adequate amounts if lacking in the diet.

Nutrients: Macronutrients or Micronutrients

• Macronutrients: Needed in large amounts (grams) daily. Examples: protein, carbohydrates, lipids and water.
• Micronutrients: Needed in small amounts (milligrams or micrograms) daily. Examples: vitamins and minerals.

Nutrients: Organic v. Inorganic

• Organic nutrients: Contain carbon. Examples: carbohydrates, lipids, proteins, and vitamins.
• Inorganic nutrients: Do not contain carbon. Examples: minerals and water.

The Six Classes of Nutrients

Energy-Yielding Nutrients

• Macronutrients are the primary source of energy in the body.
  • Carbohydrates: 4 kcal/gram
  • Protein: 4 kcal/gram
  • Fats: 9 kcal/gram
• Alcohol provides 7 kcal/gram, but it is not considered a nutrient.

Good Nutrition

• Contributes to overall good health.
• Prevents chronic conditions and diseases.
• Meets energy needs.
• Promotes a sense of well-being.
• Imbalance of nutrients can lead to malnutrition.

Why is Nutrition Important?

• Essential for growth, development, and health and wellbeing.
• Prevents future health issues and extends life.
• Nutritional status is determined by diet.

Nutritional Needs

• Based on life stage, health conditions, cultural/religious preferences, and genetics.
• Important for disease prevention and health promotion.

Human Body Composition

• Reference chemical composition for men (70kg) and women(60kg)
  • Protein (20% v. 18%)
  • Minerals (6% v. 6%)
  • Water (60% v. 50%)
  • CHO & Others(1% v. 1%)
  • Fat (13% v. 25%)

Role of Registered Dieticians

• Complete comprehensive nutritional assessments.
• Write nutritional diagnoses.
• Plan interventions.
• Monitor client or family response to the nutritional plan.

Nutritional Assessment

• A comprehensive analysis of a person's nutritional status.
  • Historical information (health status, diet history, drug use, family history)
  • Anthropometric data (height, weight, BMI, etc.)
  • Physical examinations (signs of malnutrition and other health conditions).
  • Laboratory tests (blood and urine tests to look for nutrient deficiencies, imbalances)

Anthropometric Data

• Measures used to assess nutrition status and patterns.
  • Height
  • Weight
  • BMI (Body Mass Index)
  • Growth charts (comparing children with typical growth)
  • Skinfold measurements
  • Circumference measurements (waist circumference).

Body Mass Index (BMI)

• A measure of body weight relative to height, expressed as weight (kg) / height (m)2.
• Used to classify individuals as underweight, healthy weight, overweight, or obese.

BMI Considerations

• Frame size
• Muscle mass
• Alternative measures for people with disabilities who have issues with height measurement.

Growth Indicators

• Used for children:
  • Length/height for age
  • Weight for age
  • Weight for length/height
  • BMI for age (comparing to growth charts).

Methods of determining body composition and fat distribution

• Skinfold measurements
• Circumference measurements (waist circumference)

Waist Circumference

• A practical indicator of fat distribution and central obesity.
  • Men >40 inches (>102 cm)
  • Women >35 inches (>88 cm)

BMI Classifications

• Underweight (<18.5 BMI)
• Healthy weight (18.5-24.9 BMI)
• Overweight (25-29.9 BMI)
• Pre-obese (30-34.9 BMI)
• Obese class 1 (35-39.9 BMI)
• Obese class 3 (>40 BMI)

Waist-to-Hip Ratio

• Dividing waist measurement by hip measurement.
  • "Apple" body type: Ratio > 1.0
  • "Pear" body type: Ratio < 0.8

Nutritional Assessment Types and Measurement

• Abdominal girth measurement (fluid retention and abdominal organs size)
• Height-weight (assess nutrition status and growth)
• Head circumference (brain growth and development)
• Skin-fold (subcutaneous and total body fat)
• Waist circumference (body fat distribution)

Laboratory Tests

• Samples of blood or urine to see if the body has imbalances in nutrients or deficiencies before symptoms appear. - Analyzing blood for the current level of nutrients in relation to typical values (like vitamin B12 or folate in blood cells). - Monitoring urine excretion of water-soluble nutrients. - 24-hour urine collection to check protein intake.

Laboratory Value

• Only a fraction of the overall data

Nutritional Assessment Application

• Detailed picture of dietary intake and nutritional status of a population.
• Monitoring consumption patterns and disease relations through surveillance

Stages in the Development of Nutrient Deficiency

• Primary Deficiency: Inadequate intake.
• Secondary Deficiency: Problems within the body.
• Subclinical/Declining Stages: Nutrient stores diminish and potentially disruptive functions occur in the body.
• Overt Stage: Physical symptoms and signs.

Malnutrition

• Insufficient, excessive, or unbalanced nutrient consumption.
• Can cause undernutrition or overnutrition.

Undernutrition and Overnutrition

• Undernutrition: Inadequate energy or nutrient intake.
  • Symptoms: Extreme thinness, poor wound healing, muscle loss, impaired immunity.
• Overnutrition: Excess energy or nutrient intake.
  • Symptoms: Obesity, high cholesterol, heart disease, diabetes.

Undernutrition: A Global Challenge

• A prevalent health problem.
• Can weaken the immune system, even in milder cases.
• Can increase the risk of certain diseases in developed countries.

Forms of Malnutrition

• Stunting (too short for age)
• Wasting (too thin for height)
• Obesity (overweight)

Dietary Reference Intakes (DRIs)

• Set of nutrient intake values for people in the US and Canada.
• Used for planning and assessing diets. Includes: Estimated Average Requirements (EAR), Recommended Dietary Allowances (RDA), Adequate Intakes (Al) and tolerable Upper Intake Levels (UL).

Setting Nutrient Recommendations: RDA and AI

• RDA: Daily nutrient amounts required by almost all healthy individuals at specific life stages and gender groups.
• AI: Daily intake amounts when insufficient scientific evidence to set EAR or RDA.

Facilitating Nutrition Research and Policy: EAR

• EAR: Average daily amounts of nutrients that half of the healthy population in a specific age and category require to meet needs.

EAR and RDA Compared

• RDA is set above the EAR to meet the needs of a larger portion of the population, for practical needs

Establishing Safety Guidelines: UL

• UL: Highest average daily nutrient intake likely to pose no toxicity risk for individuals at certain life stages.

Using Nutrient Recommendations

• Safe and sufficient amounts, not minimum, reflect average intakes over time, and designed for healthy people.

Inaccurate vs. Accurate View of Nutrient Intakes

• How to interpret intake levels in relation to RDA, EAR and UL

Establishing Energy Recommendations: EER

• EER: Average dietary energy intake for maintenance of energy balance and healthy body weight with consideration for physical activity level.

Acceptable Macronutrient Distribution Ranges (AMDR)

• Ranges of intakes for the energy yielding nutrients.
  • Carbohydrates 45-65%
  • Fats 20-35%
  • Protein 10-35%