Table of Contents

Overview

Nutrition Science is the interdisciplinary study of how food and nutrients affect human health, disease prevention, and overall well-being. It integrates biochemistry, physiology, molecular biology, and public health to understand the relationship between diet and health outcomes.

Core Concepts

  • Nutrient Classification: Macronutrients (carbohydrates, proteins, fats), micronutrients (vitamins, minerals).
  • Dietary Requirements: Vary by age, sex, activity level, genetics, and health status.
  • Bioavailability: The proportion of nutrients absorbed and utilized.
  • Nutrigenomics: How genes interact with nutrients to influence health.
  • Food Matrix Effect: The impact of food structure on nutrient absorption.

Macronutrients

Carbohydrates

  • Types: Simple (monosaccharides, disaccharides), complex (polysaccharides).
  • Function: Primary energy source (4 kcal/g).
  • Sources: Fruits, grains, vegetables.
  • Glycemic Index: Measures impact on blood glucose.

Proteins

  • Amino Acids: Essential (cannot be synthesized), non-essential.
  • Function: Tissue repair, enzyme production, immune function.
  • Sources: Meat, legumes, dairy.
  • Protein Quality: Biological value, digestibility.

Fats

  • Types: Saturated, unsaturated, trans fats.
  • Function: Energy storage (9 kcal/g), hormone production, cell membrane structure.
  • Sources: Oils, nuts, fatty fish.
  • Essential Fatty Acids: Omega-3, Omega-6.

Micronutrients

Vitamins

  • Fat-soluble: A, D, E, K.
  • Water-soluble: B-complex, C.
  • Roles: Antioxidant activity, coenzyme functions, vision, bone health.

Minerals

  • Major: Calcium, potassium, sodium, magnesium.
  • Trace: Iron, zinc, iodine, selenium.
  • Roles: Bone structure, oxygen transport, enzyme activation.

Digestion & Absorption

  • Process: Begins in mouth (mechanical/chemical), continues in stomach (acid/enzymes), small intestine (major absorption).
  • Transport Mechanisms: Passive diffusion, facilitated diffusion, active transport.
  • Gut Microbiota: Influences nutrient metabolism, immune function, and disease risk.

Metabolism

  • Catabolism: Breakdown of molecules for energy.
  • Anabolism: Synthesis of complex molecules.
  • Energy Balance: Intake vs. expenditure; impacts weight management and health.

Nutrition Science Mind Map

Nutrition Science Mind Map

Surprising Facts

  1. Plastic Pollution in Food Chain: Microplastics have been detected in seafood, table salt, and even drinking water, indicating that plastic pollution infiltrates the human food chain (Smith et al., 2021).
  2. Vitamin D Synthesis Variation: Skin pigmentation, latitude, and air pollution dramatically affect endogenous vitamin D synthesis, making deficiency common even in sunny regions.
  3. Nutrient Timing: The timing of nutrient intake (e.g., protein post-exercise) can influence muscle synthesis and metabolic health more than total daily intake.

Practical Applications

  • Personalized Nutrition: Genetic testing and microbiome analysis enable tailored diet plans for disease prevention and optimal health.
  • Clinical Nutrition: Used in hospitals for managing diabetes, cardiovascular disease, renal failure, and malnutrition.
  • Food Fortification: Adding micronutrients to staple foods (e.g., iodized salt, fortified cereals) to combat deficiencies.
  • Sports Nutrition: Optimizing macronutrient ratios and hydration for athletic performance.
  • Public Health Policy: Development of dietary guidelines, school meal programs, and food labeling standards.

Environmental Implications

  • Food Production Impact: Agriculture contributes to greenhouse gas emissions, deforestation, and water use.
  • Plastic Pollution: Food packaging and agricultural plastics have led to microplastic contamination in soil, water, and food products. Microplastics disrupt marine ecosystems and bioaccumulate in seafood, posing risks to human health (Peng et al., 2021).
  • Sustainable Diets: Emphasis on plant-based diets reduces environmental footprint and supports biodiversity.
  • Nutrient Runoff: Excess fertilizer use leads to eutrophication in aquatic systems, impacting food chains and water quality.

Recent Research

A 2021 study published in Science found microplastics in the Mariana Trench, the deepest part of the ocean, with evidence that these particles are ingested by bottom-dwelling organisms, entering the global food chain (Peng et al., 2021). This highlights the intersection of nutrition science and environmental health, as contaminants can affect food safety and nutrient bioavailability.

References

  • Peng, X., et al. (2021). “Microplastics in the deepest part of the ocean.” Science, 373(6553), 123-126.
  • Smith, M., et al. (2021). “Microplastics in seafood and implications for human health.” Nature Food, 2, 253–260.
  • World Health Organization. (2022). “Nutrition: Key facts.” WHO Nutrition
  • U.S. Department of Agriculture. (2023). “Dietary Guidelines for Americans.” USDA Guidelines

Diagram: Human Digestive System

Digestive System Diagram

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