(NDT) Ch. 1: The Science of Nutrition

What is Nutrition?

The scientific study of food and how it nourishes the body and influences health. (simple def.)

• This includes how we consume digest, metabolize and store nutrients

What are the determinants of our health?

1. Personal

2. Social

3. Economic

4. environmental

The evolution of nutrition includes…

• Mid 1700s: observation of an association between food and disease

• 1800s: nutrients identified

• Early 20th: research focus on nutrient deficiency diseases

• 1950s-present: Nutrition research focus on chronic diseases, supported by wellness

What is wellness?

An active process including a nutritious diet that provides a energy and functional chemicals for mental and physical tasks and boosts out ability to fight infections.

What are the two key components of wellness?

1. Nutrition

2. Physical activity

What are the 6 groups of nutrients?

1. Carbohydrates

2. Lipids (fats and oils)

3. Proteins

4. Vitamins

5. Minerals

6. Water

Which of the 6 nutrients are organic? (CONTAINS hydrogen and carbon)

1. Carbs

2. Lipids

3. Proteins

4. Vitamins

Inorganic? (Does NOT contain hydrogen or carbon)

1. Water

2. Minerals

Macronutrients

Nutrients that are required in regularly large amounts to support health and to provide energy and fuel to our bodies.

1. Carbohydrates

2. Proteins

3. Lipids

Alcohol

Not considered a nutrient, considered both a drug and toxin. Does not support the regulation of bodily functions or repairing of tissues.

Carbohydrates

(Primary fuel source for the body for neurologic functioning and physical exercise) Composed of chains of carbon, hydrogen and oxygen

• (e.g.) grains (wheat, rice), vegetables, fruits, legumes, nuts and milk products

• Fiber

Lipids (fats and oils)

(Primary fuel source for the body) Diverse group of organic substances that are largely insoluble in water. Triglycerides are the most common lipid in foods.

• (e.g.) Vegetable oils, butter, dairy, fat in animal products

Proteins

(NOT a primary source of fuel) Amino acids are the building blocks forming peptide bonds (polypeptides). Made up up hydrogen and carbon as well as NITROGEN.

• (e.g.) Meats, dairy, nuts, seeds and legumes

Kcal per gram…

1g of protein: 4 kcal

1g of carb: 4 kcal

1g of lipids: 9 kcal

Micronutrients

Nutrients that are needed in minimal amounts (mg)

1. Vitamins (fat soluble and water soluble)

2. Minerals

Vitamins

Micronutrients that assist in regulating body processes:

Vitamins are not a source of energy but aid the process of creating energy from macronutrients

Fat-soluble vitamins

Soluble in fat meaning that it’s stored in adipose tissue (Toxicity can occur due to overconsumption).

• (e.g) A, D, E, K

Water- soluble vitamin

Soluble in water, not stored heavility in the body. Excess is excreted in urine.

Minerals

Inorganic substances required for body processes (major and trace) :

• regulate fluid and energy production

• support bone and blood health

• cannot be broken down

Water

Necessary macronutrient needed for fluid balance nutrient transport and excretion of waste products.

Dietary Reference Intakes (DRIs)

Aim to reduce and prevent the risk of chronic disease (promoting optimal health). Dietary standards for HEALTHY people ONLY.

• Expands upon the RDA

• Used to refer to other nutrient based references

DRIs (Dietary reference intakes) refer to…

1. Estimated Average Requirement (EAR)

2. Recommended Dietary Allowance (RDA)

3. Adequate Intake (AI)

4. Tolerable Upper Intake Level (TUI)

5. Chronic Disease Risk Redcution (CDRR)

Estimated Average Requirement (EAR)

The average daily intake level of a nutrient to meet the needs of 50% of the healthy people.

• Used to calculate the recommended dietary allowance (RDA)

Recommended Dietary Allowance (RDA)

The average Daily nutrient intake level that meets the needs of 97-98% of healthy people in a particular life stage and sex group.

Adequate Intake (AI)

Recommended average daily nutrient intake level based on observed and experimentally determined estimates of nutrient intake by a group of healthy people.

• Used when the RDA is not available

Tolerable Upper Intake Level (TUIL)

Highest daily average nutrient intake likely to prose no risk of adverse health effects.

• Right before intoxication

• Above TUIL will increase potential risk of toxic effects

Estimated Energy Requirement

Average energy requirement to maintain energy balance in a HEALTHY adult.

• defined by age, gender, weight, height and level of physical activity

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Acceptable Macronutrient Distribution Ranges (AMDR)

Ranged of energy intakes from macronutrients that provide adequate intakes of essential nutrients while reducing the risk of chronic disease.

Anthropometrics

• Body weight, height

• waist circumference

• BMI

Malnutrition

Nutritional status is out of balance: with too much of too little of a particular nutrient.

• Overnutrition

• Undernutrition

Covert

Symptoms that are not visible to the eye and require laboratory tests

Overt

Obvious signs (visible) and symptoms of nutrient deficiency

Primary deficiency

When a person does not consume enough of a nutrient a direct consequence of inadequate intake.

Secondary deficiency

A person cannot absorb enough of a nutrient, a deficiency that is indirectly caused by something else occurring.