Nutrition Basics Study Notes

Nutrition: The science of food and dietary supplements, including how the body utilizes them for health and disease.
Essential Nutrients: Approximately 45 nutrients required from food since the body cannot manufacture them adequately. These include:
- Macronutrients: Required in larger amounts, including proteins, fats, carbohydrates, and water.
- Micronutrients: Required in smaller amounts, including vitamins and minerals.
Digestion: The process of breaking down food into usable compounds. An adequate diet provides both nutrients and energy necessary for bodily functions.

Kilocalories (kcal): The measure of energy in food, commonly referred to as calories. 1 kcal is defined as the amount of heat needed to raise the temperature of 1 liter of water by 1°C.
Sources of Energy:
- Fat: 9 calories per gram
- Protein: 4 calories per gram
- Carbohydrates: 4 calories per gram
Nutrient Density: The ratio of essential nutrients to the calories in a food, indicating its nutrient quality.

Process of Digestion:
- Food is chewed and mixed with saliva in the mouth.
- Travels down the esophagus to the stomach where acids and secretions further break it down.
- Muscular contractions in the digestive tract mix food to enhance digestion and absorption.
- Most nutrient absorption occurs in the small intestine; excess water is reabsorbed in the large intestine, with waste excreted later.

Function of Proteins: Form essential structures including muscle, bone, blood, the immune system, enzymes, hormones, and cell membranes.
Amino Acids: Building blocks of proteins.
- Types: 20 common amino acids total, 9 being essential (must be obtained from food).

Complete Proteins: Contain all essential amino acids; usually from animal sources (e.g., meat).
Incomplete Proteins: Often from plant sources; need to be combined (e.g., legumes and nuts) to form complete proteins.
Recommended Protein Intake: 0.8 grams per kilogram of body weight. The Acceptable Macronutrient Distribution Ranges (AMDR) suggest that protein should comprise 10–35% of total daily calories.

Item	Protein (g)
3 oz lean meat, poultry, fish	20–27
¼ block (3 oz) tofu	7
1 cup cooked beans	15–17
1 cup yogurt	8–13
1 oz cheese	6–8
1 egg (cooked)	6
1 cup ricotta cheese	28
1 cup milk	8
1 oz nuts	2–6
Note: For specific protein content, refer to food labels or the USDA food composition database.

Definition & Function: Fats (lipids) are the most concentrated energy source, storing energy, providing insulation and support, and serving as a major fuel source during rest and light activity.
Energy Yield: Fats provide 9 calories of energy per gram.
Essential Fatty Acids:
- Linoleic acid (omega-6)
- Alpha-linolenic acid (omega-3)
Triglycerides: The most common form of fat in foods, categorized by types:
- Saturated: Found in animal fats and some plant oils (e.g., palm).
- Monounsaturated: Found in oils like olive, canola.
- Polyunsaturated: Includes omega-3s from fatty fish and omega-6s from certain oils.

Trans Fats: Formed through hydrogenation, leading to increased risk of cardiovascular disease and other health issues. The FDA banned artificial trans fats in 2015.
Dietary Recommendations: Total fat should compose 20–35% of daily calories; saturated fat should be <10% of total calories.

Function: Carbohydrates provide energy for cells, broken down into glucose during digestion.
Types:
- Simple Carbohydrates: Monosaccharides (e.g., glucose) and disaccharides (e.g., sucrose).
- Complex Carbohydrates: Include starches and fibers.
Recommended Carbohydrate Intake: On average, Americans consume 200–300 grams daily, with a minimum of 130 grams for basic requirements. The AMDR is 45–65% of daily calories, ideally emphasizing complex carbs, especially whole grains.

Types:
- Soluble Fiber: Such as in oat bran, may delay stomach emptying.
- Insoluble Fiber: Increases fecal bulk and helps to prevent constipation.
Health Benefits: A high-fiber diet reduces the risk of type 2 diabetes, heart disease, and promotes gastrointestinal health. Recommended intake is 38 grams for men and 25 grams for women.

Definition: Carbon-containing compounds required in small amounts for various functions in the body.
Types: Four fat-soluble (A, D, E, K) and nine water-soluble vitamins (including Vitamin C and B-complex).
Functions: Aid in energy release, red blood cell production, and act as antioxidants. Sources primarily include fruits, vegetables, and grains.
Deficiencies and Toxicities:
- Deficiencies can lead to serious health risks, and vitamin excesses can be toxic.

Role: Essential for body functions, including energy release and growth maintenance.
Types:
- Major Minerals: (e.g., calcium, sodium) needed in larger amounts.
- Trace Minerals: Needed in smaller amounts but equally important (e.g., iron, zinc).
Health Issues: Deficiencies can lead to issues like anemia and osteoporosis.

Importance: Composed of 50–60% of the human body; critical for digestion and chemical reactions. Daily recommendations: Men: 3.7 liters; Women: 2.7 liters.

Dietary Reference Intakes (DRIs): Standards to prevent deficiencies and chronic disease, including RDAs, AIs, EARs, and ULs for various nutrients.
Dietary Guidelines for Americans: Emphasize healthy eating patterns adjusted for personal culture and preferences, focusing on nutrient-dense foods and limiting sugars, fats, and sodium.
MyPlate: Guide for food groups at meals, promoting a balanced diet.

Understanding Labels: Daily Values inform nutritional contributions based on a 2000-calorie diet. Claims like "healthy" involve meeting specific criteria for nutrient limits.
Safety and Efficacy: QC on supplements and labels regarding nutrient content helps consumers make informed choices.

Specific dietary needs for children, teens, pregnant women, the elderly, and athletes.

Utilize food labels for informed decision-making. Pay attention to nutrient content and consider dietary needs, especially related to potential deficiencies and excesses.