Nutrients and Homeostasis

Macromolecules vs. Macronutrients

Macromolecules are large, complex molecules that make up polymers

4 MACROMOLECULES:• Carbohydrates• Proteins• Fats• Nucleic Acids

Macronutrient is a type of food required in large amounts in the human diet

6 GROUPS OF NUTRIENTS: • Carbohydrates• Proteins• Fats• Vitamins• Minerals• Water

What are Carbohydrates?• Should make-up ~50-60% of daily calories• Purpose:

– Provide the body with short term energy– Preferred energy source– Our body converts all carbohydrates to glucose (simple

sugar)– Carbohydrates not used will be stored by your body as fat

• Two types:– Simple– Complex

What are Simple Carbohydrates?• Easily broken down• Provides quick energy• Simple sugars are probably the largest source of

cellular energy • Examples:

– Glucose– Fructose– Lactose

Fruit is a type of simple carbohydrate, like cake. But, why is fruit a better option for fuel than cake? What are some

differences?

What are Complex Carbohydrates? • Broken down more slowly

– More fiber– Feel fuller, for longer

• Majority of carbohydrates in your diet should be complex carbohydrates!

• Examples:– Whole grains– Legumes – Seeds

Proteins• Purpose:

– Promotes muscle and connective tissue growth– Formation of antibodies to strengthen immune system– Foundation of hormones, enzymes, and blood cells

• 10-35% of your daily calories should come from protein

• Two Types:– Complete– Incomplete

Complete vs Incomplete Proteins

• Complete Protein– Contains amounts of 9 essential amino acids– Examples: fish, meat, poultry, eggs, milk, cheese,

yogurt, soy• Incomplete Protein

– Lack 1+ essential amino acids – Examples: beans, peas, nuts and whole grains

What are Fats?• Fats are a type of lipid, a fatty substance that does not

dissolve in water (hydro-phobic)• 20-30% of your daily calories should come from fat• Purpose:

– Essential for absorption of some vitamins– Long term energy storage → keeps you FULL! – Protects body organs/cell membranes

• The “building blocks of fats” are called fatty acids • Two types:

– Saturated– Unsaturated

What are Saturated Fats?• Straight, fatty acid chain with all single bonds• Easier for body to break down, but not as useful • Solid at room temp• Most ANIMAL fats

– Examples:• White, visible fat found in meats• Lard, Crisco, butter• Coconut and palm oils• Dairy products

✦ Whole milk✦ Cream✦ Hard cheeses

• High intake is associated with an increased risk of heart disease and high cholesterol

What are Unsaturated fats?• Kinked, fatty acid chain

with a double bond• Harder for body to break

down, but more useful• Liquid at room temp• Most PLANT fats

– Examples:• Olive, vegetable, and canola

oil• Nuts/nut butters• Fish oils• Avocado • Associated with a reduced risk of

heart disease

Nucleic Acids

•A large chain of nucleotides:–Phosphate–Sugar–Nitrogen Base

•NA make up:–DNA–RNA

Function of Nucleic Acids

•Stores genetic information •Gene – specific piece of DNA that codes for a specific protein

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Vitamins & Minerals

• Vitamins are compounds that help regulate many vital body processes that include digestion, absorption, metabolism, and circulation

• We will break this down into three types:– Water Soluble Vitamins– Fat Soluble Vitamins– Minerals

What does it mean for something to be SOLUBLE??

Vitamins & MineralsWater-soluble vitamins

• Dissolve in water and pass easily into the blood during digestion• The body does not store these so they need to be replenished

regularly • Includes vitamins C, B1 ,B2, Niacin, B6, Folic acid, and B12

Fat-soluble vitamins • Absorbed, stored, and transported in fat• Body stores these vitamins in fatty tissue, liver, and kidneys • Excess buildup can be toxic → including vitamins A, D, E, and K

Minerals• Substances that the body cannot manufacture• Needed for forming healthy bones and teeth• Important minerals include calcium, phosphorus, magnesium, and iron

Why is Water Important?• Water makes up, up to 65% of our body • Water helps maintain bodily functions

• Lubricates joints and mucous membranes• Helps us swallow and digest foods • Absorbs other nutrients and eliminates waste• Sweat helps us maintain a normal body temperature

• It’s important to drink at least 8 cups of water/ day to maintain health

How Many Calories Do I Need?• What is a calorie?

– unit used to measure the energy value of foods– men and women have different caloric needs

How Many Calories Do I Need?

• To burn 1 pound of fat you must burn 3,500 calories– 1 pound a week = 500 calories a day burned– 2 pounds a week = 1,000 calories a day burned

• So, how do we figure out how to eat the right amount of calories?– Reading nutrition labels– Calculating calories in/out

• Product labeling shows a food’s nutritious value

• Some common used terms are light, less, free, more, rich, rich in, lean, or excellent source of…

• Many food products have open dates on their label• Examples are

expiration date, freshness date, pack date, and sell-by date

Understanding Nutritional Labels • Start with the serving

size– Provided in units like

cups, grams, or pieces…

• Try to pay attention to the serving size (how many servings there are in the food package)– Example: A package of

pop-tarts is TWO servings

Understanding Nutritional Labels • Next, look at the calories (& calories from fat)

– We usually consume more calories than we need WITHOUT meeting our RDA for vitamins/nutrients

• Rule of thumb – for a 2000 calories diet– 40 calories is low– 100 calories is moderate– 400+ calories is high

Understanding Nutritional Labels

Limit These Nutrients Get Enough of These!

Nutrients are next!

Understanding Nutritional Labels • Finally, Daily Values (DV)• Foot note at the bottom of all labels shows the DVs for a 2,000

and 2,500 calorie diet– Notice cholesterol and sodium do not increase

• These are values to use as a benchmark when eating (based on a 2,000 calorie diet):

Nutrient DV DV% Goal

Total Fat 65 g = 100%DV Less than

Sat. Fat 20 g = 100%DV Less than

Cholesterol 300 mg = 100%DV Less than

Sodium 2400 mg = 100%DV Less than

Total Carbohydrates 300 g = 100%DV At least

Dietary Fiber 25 g = 100%DV At least

Understanding Nutritional Labels • Daily Values Percentages (DV%) are

recommendations for a 2,000 calories diet ONLY

• Helps determine if a serving of food is high or low in a nutrient

• Rule of thumb: 5% is low, 20% is high • Example – This mac & cheese food makes up

18% of the fat for a 2,000 calorie diet

Notice how much fat you will still have for your diet if you eat 1 serving….or 2….