Nutrition Fundamentals

General Nutritional Information

• ATI Books: Excellent resource for nurse-focused nutritional information.

• Numbers & Ranges: Focus on understanding ranges (e.g., high/low) rather than memorizing exact numerical values.

• Caloric Needs: General range for adults and older adults is $1600$ to $2400$ calories/day, based on age and activity level.

• FDA Guidelines & Food Labels: Indicate serving size, calories, servings per container, added sugars (grams), and specific vitamin breakdowns (Vitamin D, Iron, Calcium, Potassium – common deficiencies).

• MyPlate Recommendation: Emphasizes large portions of fruits and vegetables, at least half whole grains, lean proteins, fat-free or low-fat dairy, and limited healthy oils.

Essential Macronutrients

• Protein

  • Function: Primary building block; new tissue production, antibody/enzyme/hormone formation, heat/energy, fluid balance, acid-base balance.

  • Calories: $4 ext{ kcal/unit}$.

  • Types: Nonessential (produced by liver), Essential (obtained from food).

  • Amino Acids: Complete (all nine essential, from animal/some plant/soy) vs. Incomplete (from plants; can be combined to form complete).

  • Digestion: Begins in stomach (pepsin), continues in small intestine (trypsin).

  • Deficiency: Kwashiorkor (severe protein deficiency, causes ascites, enlarged liver).

  • Excess: Stored as fat, may worsen kidney disease.

• Fats (Lipids)

  • Function: Necessary micronutrient; forms cell membranes, produces adrenal/sex hormones, aids bile production, protects nerves, converts sunshine to Vitamin D, metabolizes fat-soluble vitamins.

  • Calories: $9 ext{ kcal/unit}$.

  • Types:

    • Monounsaturated: Solid when cold (olive, canola, peanut oils); lowers LDL cholesterol.

    • Polyunsaturated: (Corn, soybean, sesame, safflower oils); decreases risk of Type $2$ diabetes and cardiovascular disease.

    • Saturated: Solid at room temperature (animal sources, packaged foods); raises cholesterol.

    • Trans Fats: Hydrogenated oils; used for freshness, raise cholesterol, FDA aiming to remove.

  • Cholesterol (Manufactured by liver):

    • LDL (Low-Density Lipoproteins): "Lousy" cholesterol; transports to cells, can build up in arteries.

    • HDL (High-Density Lipoproteins): "Healthy" cholesterol; transports excess back to the liver.

    • Triglycerides: Fat cholesterol; excess stored in fat cells, leads to cardiovascular disease and metabolic syndromes.

  • Digestion: Longer in stomach, bulk in small intestine (bile acids, lipase).

  • Deficiency: Impaired absorption of fat-soluble vitamins (A, D, E, K).

  • Excess: Obesity, cardiovascular disease, metabolic syndrome.

• Carbohydrates (Carbs)

  • Function: Primary energy source.

  • Calories: $4 ext{ kcal/unit}$.

  • Types: Simple (quick energy, 1-2 sugars), Complex (slower digestion, starch/fiber component).

  • Digestion: Amylase breaks down carbs, primarily in duodenum. Always broken down to sugar.

  • Deficiency: Lack of energy.

  • Excess: Weight gain, obesity, metabolic syndrome.

• Fiber

  • Types: Soluble (digested, attracts water), Insoluble (not digested, draws water into large intestine).

  • Function: Decreases LDL, promotes normal bowel function, increases mineral absorption, lowers colon pH (decreases cancer risk), feeds GI flora.

Essential Micronutrients

• Vitamins

  • Water-Soluble: B vitamins (B1, B6, B12 are key) and C vitamins. Not stored, pass through body.

  • Fat-Soluble: A, D, E, K. Stored in fat; excess can lead to toxicity.

  • Key Functions:

    • Vitamin K: Blood clotting.

    • Vitamin A: Vision, skin.

    • Vitamin D: Bone health, calcium absorption.

    • Vitamin E: Skin protection.

    • Vitamin B1: Carbohydrate metabolism.

    • Vitamin B6: Protein metabolism.

    • Vitamin B12: Red blood cell production.

    • Vitamin C: Antioxidant, found in citrus fruits.

  • Antioxidants (A, C, E): Repair damage by deactivating free radicals.

  • Deficiencies: Usually due to malabsorption or poor habits.

• Minerals

  • Source: From the earth, cannot be digested.

  • Function: Forms body structures (bones, teeth, nails), assists in water metabolism, fluid/electrolyte balance, enzyme activation, acid-base balance, nerve/muscle contraction.

  • Key Minerals & Functions:

    • Calcium: Most abundant in body, stored in bones; needs Vitamin D for absorption.

    • Iron: Essential for protein and hemoglobin, transports oxygen.

    • Magnesium: Muscle contraction, nerve conduction.

    • Potassium: Nerve conduction, heart muscle.

    • Sodium: Fluid balance, acid-base regulation.

  • Deficiencies: Often from restrictive diets (e.g., iron deficiency).

Water

• Importance: Most critical component to sustain life; most of the body is water.

• Function: Essential for every body function.

• Balance: Essential; too much or too little can be detrimental.

• Increased Needs: Fever, illness, higher body fat percentage.

Nutritional Needs Over the Lifespan

• Adults: Requirements decrease with age; based on age, sex, height, weight, activity. Women specifically need more calcium and less iron post-childbearing age.

• Older Adults: Decreased appetite, GI absorption/motility, impaired digestion, less physical activity, more fat stores, potential financial impact on food choices leading to nutrient deficiencies over calorie intake. Increased needs for Calcium and Vitamin D (they aid each other's absorption).

Obesity

• BMI (Body Mass Index): Used as a reference to determine obesity risk and associated comorbidities. Not perfect (muscle mass can skew results), but requires height and weight for calculation.