Nutrition Basics and Essential Nutrients Overview

nutrition

the science of food and how the body uses it in health and disease

essential nutrients

substances the body must get from food because it cannot manufacture them at all or fast enough to meet its needs; include proteins, fats, carbohydrates, vitamins, minerals and water

macronutrients

an essential nutrient required by the body in relatively large amounts

micronutrients

an essential nutrient required by the body in minute amounts

digestion

the process of breaking down foods in the gastrointestinal tract into compounds the body can absorb

kilocalorie

a measure of energy content in food; one kilocalorie represents the amount of heat needed to raise the temperature of one litre of water by one degree Celsius

protein

an essential nutrient; a compound made of amino acids that contains carbon, hydrogen, oxygen and nitrogen

amino acid

the building blocks of proteins

complete protein

supplies all the essential amino acids in adequate amounts

incomplete protein

do not supply all the essential amino acids

legumes

vegetables, such as peas and beans, that are high in fibre and are also important sources of protein

Recommended protein intake

Adults: 0.8g/kg of body weight; DRI = 10-35% of total calories should be protein

fats

most concentrated source of energy

hydrogenation

a process by which hydrogens are added to unsaturated fats, increasing the degree of saturation and turning liquid oils into solid fats

trans fatty acid

a type of unsaturated fatty acid produced during the process of hydrogenation; trans fats have an atypical shape that affects their chemical activity

cholesterol

a waxy substance found in the blood and cells and needed for synthesis of cell membranes, vitamin D and hormones

low-density lipoprotein (LDL)

blood fat that transports cholesterol to organs and tissues; excess amounts result in the accumulation of deposits on artery walls

high-density lipoprotein (HDL)

blood fat that helps transport cholesterol out of the arteries, thereby protecting against heart disease

omega-3 fatty acids

polyunsaturated fatty acids commonly found in fish oils that are beneficial to cardiovascular health

Recommended fat intake

adult men need 17g/day of linoleic acid; 1.6g/day alpha linolenic acid; adult women need 12g/day of linoleic acid; 1.1g/day alpha linolenic acid

carbohydrates

an essential nutrient; sugars, starches, and dietary fibre are all carbohydrates

simple carbohydrates

sugars such as sucrose, fructose, lactose, maltose that provide sweetness in foods

complex carbohydrates

starches and dietary fiber that are primarily needed to supply energy for body cells and during high intensity exercise

total fat intake

20-35% of total daily calories

protein intake

10-35% of total daily calories

carbohydrate intake

45-60% of total daily calories

Complex carbohydrates

Starches and most types of dietary fibre (i.e. grains, fruits & vegetables).

Glucose

A simple sugar that is the body's basic fuel.

Insulin

Hormone released by the pancreas that signals cells to take up glucose.

Glycogen

An animal starch stored in the muscles and the liver.

Whole grain

The entire edible portion of a grain, such as wheat, rice, or oats, consisting of the germ, endosperm, and bran.

Germ

Provides nourishment for the seed and contains antioxidants, vitamin E and B vitamins.

Endosperm

Starchy middle portion that provides energy and contains carbohydrates and proteins.

Bran

Outer shell that protects the seed and contains fibre, B vitamins and trace minerals.

Refined carbohydrates

Only endosperm remains, becomes white flour, rice, etc., and is lower in fibre, vitamins, minerals, etc. than unrefined counterpart.

Unrefined carbohydrates

Tend to take longer to digest, enter the bloodstream more slowly, and are high in fibre.

Glycemic index

A measure of how the ingestion of a particular food affects blood glucose levels.

Recommended carbohydrate intake

45-65% of total calories, or 225-325g/2000 cal diet.

Fibre

Non-digestible and passes through the intestine, providing the bulk for feces.

Dietary fibre

Non-digestible carbohydrates and lignin that are intact in plants.

Functional fibre

Non-digestible carbohydrates either isolated from natural sources or synthesized; may be added to foods and dietary supplements.

Total fibre

The total amount of dietary fibre and functional fibre in the diet.

Soluble fibre

Fibre that dissolves in water or is broken down by bacteria in the large intestine.

Insoluble fibre

Fibre that does not dissolve in water and is not broken down by bacteria in the large intestine.

Recommended fibre intake

38g/day for adult men and 25g/day for adult women.

Vitamin

Carbon-containing substances needed in small amounts to help promote and regulate chemical reactions and processes in the body.

Fat soluble vitamins

4 vitamins (A, D, E, K) that are carried in the bloodstream by special proteins and stored in the liver and fat tissues.

Water soluble vitamins

9 vitamins (8 B-complex and C) that are readily absorbed into the bloodstream and excess are excreted through urine.

Antioxidant

A substance that can lessen the breakdown of food or body constituents by free radicals.

Vitamin deficiencies

Conditions resulting from lack of specific vitamins, such as scurvy (lack of vitamin C) and rickets (lack of vitamin D).

Anemia

A deficiency in the oxygen-carrying material in the red blood cells.

Osteoporosis

A condition in which the bones become extremely thin and brittle and break easily.

Recommended water intake

3.7 L/day for men and 2.7 L/day for women.

Free radical

An electron-seeking compound that can react with fats, proteins and DNA, damaging cell membranes and mutating genes.

Phytochemical

A naturally occurring substance found in plant foods that may help prevent and treat chronic diseases.

Cruciferous vegetables

Vegetables of the cabbage family, including cabbage, broccoli, Brussels sprouts, kale, and cauliflower.

Dietary Reference Intakes (DRIs)

An umbrella term for four types of nutrient standards.

Estimated Average Requirement (EAR)

Nutrient amount for half a population's needs.

Adequate Intake (AI)

Intake level when RDA data is insufficient.

Recommended Daily Allowance (RDA)

Daily intake level to prevent deficiencies.

Tolerable Upper Intake Level (UL)

Maximum intake unlikely to cause health issues.

Daily Values

Simplified RDAs used on food labels.

Guidelines for Healthy Eating

Principles for reducing chronic disease risk.

Healthy Eating Goals

Enjoy variety, limit fats, and maintain weight.

Eating Well with Canada's Food Guide

Food-group plan for balanced nutrient intake.

Physical Activity Benefits

Improves fitness and reduces chronic disease risk.

Fat Intake Goals

Total fat: 20-35% of daily calories.

Saturated Fat Limit

Less than 7% of total daily calories.

Trans Fat Limit

Less than 2% of total caloric intake.

Cholesterol Limit

Less than 300 mg per day.

Omega-3 Fatty Acids

Two servings of fish weekly recommended.

Sodium Intake Recommendation

Limit to less than 2300 mg/day.

Potassium Benefits

Helps lower blood pressure levels.

Alcohol Consumption Guidelines

1 drink/day for women, 2 for men.

Mediterranean Diet

Emphasizes vegetables, fruits, whole grains.

Canada's Food Guide Purpose

Guides food selection for nutritional health.

Grains Serving Example

1 slice of bread or 1 cup cereal.

Vegetables Serving Example

½ cup of raw or cooked vegetables.

Fruits Serving Example

1 small whole fruit or ½ cup juice.

Milk Serving Example

1 cup of milk or fortified soy beverage.

Meat Serving Example

75 g of cooked meat or 2 eggs.

Vegetarianism

Diet linked to lower chronic disease risk.

Lacto-Vegetarian

Includes milk and cheese in diet.

Lacto-Ovo-Vegetarian

Eats eggs and dairy, excludes meat.

Pescovegetarian

Includes seafood, eggs, and dairy.

Discretionary Calorie Allowance

Extra calories after meeting nutrient needs.

Vitamin B12

Essential vitamin found only in animal foods.

Vitamin D

Nutrient obtained from sunlight and fortified products.

Calcium

Mineral found in dairy, legumes, and fortified foods.

Iron

Mineral harder to absorb from plant sources.

Zinc

Mineral found in whole grains and legumes.

Dietary Challenges

Obstacles faced by specific population groups.

Children & Teens

Need nutrient-rich foods for growth.

College Students

Often prioritize convenience over health.

Older Adults

Require nutrient-dense foods due to absorption issues.

Athletes

Need increased energy and carbohydrates.

Low-Income Families

Struggle to meet nutritional needs.

First Nations, Metis, Inuit

Face unique challenges in food preparation.

Pregnant Women

Have increased nutrient requirements.

Food Labels

Provide serving sizes and nutrient information.