Introduction to Nutrition

What is Nutrition?

• Study of food and its impact on energy, health, and bodily functions.
• Key factors:
  • Food usage for energy.
  • Impact on health (positive & negative).

Nutrition's Role in Health

• Nutrition impacts leading causes of death (e.g., heart disease).
• Poor diet is a major lifestyle factor impacting health.

Nutrient Classification

• Six main classes: Carbohydrates, Protein, Lipids, Vitamins, Minerals, Water.
• Organic vs. Inorganic:
  • Organic contains carbon (Carbs, Proteins, Lipids, Vitamins).
  • Inorganic lacks carbon (Minerals, Water).
• Macro vs. Micro Nutrients:
  • Macronutrients: Carbs, Lipids, Proteins, Water (needed in large amounts).
  • Micronutrients: Vitamins, Minerals (needed in small amounts).

Energy and Calories

• Macronutrients providing calories: Carbs (4 cal/g), Proteins (4 cal/g), Lipids (9 cal/g).
• Water does not provide calories.
• Alcohol provides 7 cal/g but is not a nutrient.

Factors Influencing Food Choices

• Personal Taste: Influenced by genetics and dietary habits.
• Traditions & Social Interactions:
  • Cultural and social influences on dietary choices.
• Availability & Convenience:
  • Access to certain foods affects consumption.
• Emotions & Values:
  • Stress or comfort eating, religious beliefs, body image, etc.

Nutrient Recommendations and Research

• Importance of scientific methods in nutritional research.
• Types of Studies:
  • Experimental and Observational studies.
  • Cross-sectional, Case-Control, Cohort studies.
• Correlations: Positive (both increase/decrease) and Negative (inverse relationship).
• Research Validity:
  • Replication, Peer Review, Placebo control.

Dietary Reference Intakes (DRIs)

• EAR (Estimated Average Requirements): Average population needs.
• RDA (Recommended Dietary Allowance): Covers most of the population.
• AI (Adequate Intake): Used when RDA cannot be determined.
• UL (Tolerable Upper Intake Level): Maximum before it becomes harmful.
• EER (Estimated Energy Requirement): Caloric needs estimation.
• AMDR (Acceptable Macronutrient Distribution Range):
  • Carbs: 45-65%, Protein: 10-35%, Fat: 20-35%.

Nutrition Assessment

• Evaluating nutrition balance:
  • Malnutrition: Includes undernutrition and overnutrition.
  • Assessment through diet history, anthropometrics, physical exams, lab tests.

National Nutrition Assessments

• Government initiatives (e.g., Healthy People) for public health goals.
• Recommendations based on population surveys.

Reliable Nutrition Information

• Verify sources, prefer sites ending in .gov or .edu.
• Be cautious of exaggerated news and unreliable online sources.
• Consult Registered Dietitians for expert advice.
• Be wary of misleading marketing by manufacturers (e.g., "Natural" labels).