Basic Dietary Requirements

Required to maintain life, support basic physiological functions, and prevent deficiencies.

These represent what your body needs at rest (before considering illness, stress, or increased activity).

1. Energy (Calories)

  • Needed to fuel the body’s basal metabolic rate (BMR), thermoregulation, and daily activity.

  • Average daily needs (can vary with age, sex, weight, and activity):

    • Adult women: ~1,600–2,400 kcal/day

    • Adult men: ~2,000–3,000 kcal/day

      Requirement Daily Requirement Notes
      Energy Women: 1,600–2,400 kcalMen: 2,000–3,000 kcal Depends on age, size, and activity level

2. Macronutrients

  • Carbohydrates:

    • Main energy source for brain and muscles.

    • Baseline: ~45–65% of daily calories (~130 g/day minimum for brain glucose needs).

  • Proteins:
    • For tissue repair, enzymes, hormones, and immunity.
    • Baseline: ~0.8 g/kg body weight/day (higher in illness, growth, or pregnancy).
  • Fats:
    • For energy, fat-soluble vitamin absorption, hormone production, and cell membranes.

    • Baseline: ~20–35% of daily calories, with essential fatty acids (omega-3, omega-6).

      Dietrary Requirement Daily Requirement Notes
      Carbohydrates 45–65% of calories(≥130 g/day minimum) Primary energy source, especially for brain
      Protein 0.8 g/kg body weight (~46 g women, ~56 g men) Higher if ill, elderly, or active
      Fat (total) 20–35% of calories Include essential fatty acids
      • Omega-6 (linoleic acid) Women: 12 gMen: 17 g Vegetable oils, nuts, seeds
      • Omega-3 (ALA) Women: 1.1 gMen: 1.6 g Flax, walnuts, fatty fish
      Fiber Women: 25 gMen: 38 g Whole grains, fruits, vegetables
      Water Women: 2.7 LMen: 3.7 L From fluids + food combined

3. Water

  • Vital for all biochemical reactions, temperature regulation, and waste removal.

  • Baseline: ~2.7 liters/day (women), ~3.7 liters/day (men), from fluids + food

    Dietrary Requirement Daily Requirement Notes
    Fiber Women: 25 gMen: 38 g Whole grains, fruits, vegetables
    Water Women: 2.7 LMen: 3.7 L From fluids + food combined

     


4. Micronutrients (Vitamins & Minerals)

Vitamins include fat-soluble vitamins (A, D, E, K) and water-soluble vitamins (B-complex and C).

  • e.g., Vitamin A (vision, immunity), Vitamin D (bone health), Vitamin C (collagen, antioxidant), B-complex (energy metabolism).

Each plays specific roles in metabolism, immune function, and cellular processes.

Minerals: e.g., Calcium (bones, muscle contraction), Iron (hemoglobin), Magnesium (enzymes, muscles), Zinc (wound healing), Sodium/Potassium (electrolytes, nerve signals).oxygen transport, muscle function, and countless enzymatic reactions.

 

5. Fiber (non-digestible carbs, important for gut health)

  • Baseline: ~25 g/day (women), ~38 g/day (men).

    Fiber supports digestive health and helps regulate blood sugar and cholesterol.


 

Here’s a concise table of the baseline daily nutritional needs for a healthy adult (based on U.S. Dietary Guidelines and WHO recommendations):


 


Key Vitamins

Vitamin Daily Requirement Function
A 700 µg (women), 900 µg (men) Vision, immunity
D 600 IU (15 µg) Bone health, immunity
E 15 mg Antioxidant
K 90 µg (women), 120 µg (men) Blood clotting
C 75 mg (women), 90 mg (men) Collagen, immunity
B1 (Thiamine) 1.1 mg (women), 1.2 mg (men) Energy metabolism
B2 (Riboflavin) 1.1 mg (women), 1.3 mg (men) Energy metabolism
B3 (Niacin) 14 mg (women), 16 mg (men) Metabolism, skin, nerves
B6 1.3–1.7 mg Amino acid metabolism
B12 2.4 µg Nerve health, red blood cells
Folate 400 µg DNA synthesis, pregnancy health

Key Minerals

Mineral Daily Requirement Function
Calcium 1,000 mg Bones, nerves, muscles
Iron 18 mg (women), 8 mg (men) Hemoglobin, energy
Magnesium 310–320 mg (women), 400–420 mg (men) Enzymes, muscles
Potassium 2,600 mg (women), 3,400 mg (men) Fluid balance, heart
Sodium ≤2,300 mg (ideal <1,500 mg) Fluid balance, nerves
Zinc 8 mg (women), 11 mg (men) Wound healing, immunity
Phosphorus 700 mg Energy, bones
Iodine 150 µg Thyroid function
Selenium 55 µg Antioxidant

Requirements can change with age, sex, pregnancy, illness, or activity level.

Individual needs can differ substantially from general recommendations, which is why personalized nutrition approaches are often most effective.

Nutrients and Nutrition

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