Sports Nutrition Exam 2

3 Carbohydrate Types

1. Simple Carbs

2. Complex Carbs

3. Dietary Fiber

Simple Carbs

• known as sugar

• monosaccharides and disaccharides

Monosaccharides

• glucose

• fructose

• galactose

Disaccharides

• each contains at least one glucose

glucose + glucose =

maltose

glucose + fructose =

sucrose (table sugar)

glucose + galactose =

lactose - milk sugar

Complex Carbs

• polysaccharides

• chain length and are often up to thousands of sugar links

Storage form in animals

glycogen

Storage form in animals

Starch

Starch

• you EAT starch

• body breaks it down into monosaccharides

• then converted to glucose by liver

• then reassembled into glycogen and stored

Where is glycogen stored?

• liver

• individual muscles

Fiber

• has no calories

• is a complex carb

• can be mechanically digested

Fiber cannot be:

• chemically digested

• absorbed

Total fiber =

• dietary fiber (intact foods)

• functional fiber (isolated - Metamucil)

• normal intake = 12-14g

• daily value % = 25g/day

Carbs organic compounds that contain:

1. carbon

2. hydrogen

3. oxygen

Carbs are also known as sugar

• some are refined (pepsi)

• some are natural sugars (honey)

• all sugars = carbohydrates

What is the major nutrient utilized by atheletes

CARBS

1 g of carbs = ? calories

4 calories

Can the body survive without carbs?

yes; only if enough protein and fiber is consumed

The no card diet can lead to…

certain deficiencies

How many carbs?

RDA = 130g / day (for brain function)

diabetic = <250g / day

average = 300-500g / day

athletes = 400-700g / day

blood glucose

• “blood suagr”

• changes by the minute

• used for energy

blood glucose is converted into

• glycogen

• fat & then stored

• or excreted in the urine

• must be maintained at a certain level for normal metabolism

hypoglycemia

low blood glucose “sugar”

hyperglycemia

high blood glucose “sugar”

normal blood glucose levels

70-110 mg/dL

What is normal after eating carbs?

elevated / increased blood glucose

what is the name of the effect that occurs when blood glucose increases after eating carbs?

glycemic index

glycemic index

• controversial and dismissed by some

• numbers are 1-100, 100 being highest

• peoples glycemic responses differ

• food prep can change glycemic effects

which has a higher glycemic index? potato chips or regular potatoes?

regular potatoes

order of digestion

1. mouth

2. esophagus

3. stomach

4. small intestine (SI)

5. large intestine

2 ways food is broken down

1. mechanically

2. chemically

what occurs before absorption?

digestion

do monosacchrides and cholestoral get digested?

no; already in smallest form

what do capillaries on villi in the small intestines pick up?

carbs and proteins

fat is picked up by…

lymph vessels

Where does the digestion of starch begin?

the mouth through mechanical digestion

Where do simple sugars start to digest?

in the small intestine

Monosaccharides travel to the liver after absorption through the?

Portal vein

The liver converts ___ & ___ into ___.

fructose and galactose to glucose

3 sources of available carbs

1) blood glucose

2) liver glycogen

3) muscle glycogen

blood glucose is increased by…

• liver releasing glucose

• absorption from intestine

liver glycogen is created by…

• monos from bloodstream

• liver making its own from protein/fat

muscle glycogen…

• increased from blood glucose

• cannot be released back into bloodstream

• is locked in their muscle

how does insulin work?

activates receptors to let glucose enter the cell

Can exercise also activate receptors to let glucose in cell?

yes, exercise can

what does low level of BG / muscle glycogen lead to?

premature onset of fatigue

does training increase or decrease the ability of muscle to store and use carbs

increase

carb loading

Promotes a significant increase in the glycogen content of the liver and muscles

how many days out from competition should one start carb loading?

3-7 days

what are the 2 carb loading techniques

1) classic

2) current

Current technique

• change to a very-high carb diet 3-7 days before comp

• combined with rest or reduced activity a few days before event

how to know if the carb loading worked?

• muscle biopsy

• increased weight (2-3 lbs)

1g of glycogen has how many g of water?

3g of water for 1g glycogen

Does carb loading make you faster as an athlete?

no, it does not make you faster

what does carb loading do?

• enables athletes to perform longer at a given speed

• postpones fatigue

glyconeogenesis

the formation of carbs from molecules that aren’t carbs, like amino acids (protein building blocks) and glycerol from fat

insulin

a hormone secreted by the pancreas, involved in carbohydrate metabolsim

glucagon

a hormone secreted by the pancreas; basically it exerts actions just the opposite of insulin, i.e., it responds to hypoglycemia and helps to increase blood sugar levels

exogenous

meaning a substance, nutrient, or compound originating from outside of the body and introduced through injection, ingestion, or infusion.

endogenous

substances, nutrients, and compounds that originate or are produced in the body

What artificial sweetener is made from coal tar?

Saccharin

Which artificial sweetener had 4 Cal / g?

Aspartame

Which artificial sweetner is sugar that’s been altered?

Sucralose

How much energy does fat provide?

9 Cal / g

Why do we need fat?

• provides energy

• provides essential FAs

• essential for fat-soluble vitamins

• protects and insulates body

• forms body structures

• helps regulate metabolism

What is dietary fat vs. adipose fat?

Fat we eat vs. fat we store

Can you survive without dietary fats?

NO we cannot

Is fat used during athletic events

yes it is used

What are two essential fats?

Linolenic (Omega-3) and Linoleic (Omega-6)

Linolenic (Omega-3) fat examples

spinach, canola oil, leafy greens, chia seeds, flaxseeds

Linoleic (Omega-6) fat examples

corn oil, sunflower oil, peanut oil, corn, soybean oil

3 types of lipids

triglycerides, cholesterol, and phospholipids

How are triglycerides composed?

3 FAs + glycerol; think E shaped with glycerin backbone

Triglycerides are the principle lipids we eat and store.

True

Can each FA in a triglyceride be different kind and saturation?

Yes, they can be different

Saturated Fat

all carbon bonds are filled with hydrogen

Monounsaturated Fats

has one double bond

Polyunsaturated fat

has 2 or more double bonds

Cooking oils have

all 3 types of FAs

How are cooking oils classified?

By which FA makes the majority of the oil

Olive Oil is an example of what FA?

monounsaturated fats

Corn oil is an example of what FA?

polyunsaturated fats

Coconut oil is an example of what FA?

saturated fats.

Coconut oil have a ___ ___ on LDL

negative effect

Polyunsatured fats include:

Omega-3s and Omega-6s

Saturated Fats

• found in animal products

• usually solid at room temp

• coconut oil, palm oil, palm kernel oil

Polyunsaturated and Monounsaturated fats

• typically found in plant foods

• typically liquid at room temp

Trans Fats

• exist naturally in small amounts

• large amounts created by hydrogenation

Hydrogenation

makes a liquid oil into a solid

High intake of trans fats can…

increase the risk of heart disease and or lead to heart disease

Examples of trans fats:

• margarine, peanut butter, convenience foods

Cholesterol

• is in all animal products

• is NOT found in plant foods

• is NONessential

Is cholesterol digested?

No, it is just absorbed since its already in its smallest form

Phospholipids

• a combo of phosphorus and lipids

• non-essential

• ex: lecithin

Where does the digestion of Dietary Fats begin?

in the SI where bile is then released

Triglycerides are emulsified to allow for digestion, why?

Because fat and water don’t mix due to different densities, so to try and absorb/digest the fat, the stomach needs to emulsify.

How the TGs broken up?

into glycerin and FAs

After passing through the SI wall, what happens to the fat components?

They are repackaged into chylomicron which enters the lymphatic system