What is the recommended RDA for adults?
130 g/day
4 kcal/g
amount of heat required to raise 1 kg of water by 1 degree celcius
What are some sources of sugars?
fruit, soda, dairy products, candy, juice, honey
What are some sources of starch?
bread, potatoes, rice, corn, peas
What is the definition of natural sugar?
sugar that is found as part of food in nature
What are some examples of natural sugars?
lactose in milk
glucose and fructose in fruit, honey, etc.
What is the definition of added sugars?
natural sugars not found naturally in that particular food
What are some examples of added sugars?
high fructose corn syrup
sucrose in soda
What are some examples of whole grains?
buckwheat, bulgar, corn, millet, brown, rice, rye, oats, sorghum, wheat and wile rice
Endosperm = ?
starch
germ = ?
oil
Bran = ?
insoluble fiber
What is the definition of whole grains?
the starchy endosperm, germ and bran that are present in the same relative proportions as they would be seen in the intact grain
When fasting, what is the normal blood glucose?
70-99 mg/dL
When fasting, what is a diabetic blood glucose?
greater than 125 mg/dL
What is blood glucose regulated by?
peptide hormones (insulin and glucagon)
Describe what happens when there is high blood glucose.
- pancreas shuttles glucose from blood to the muscle and adipose cells, stimulating production of GLUT 4
- blood glucose decreases back to normal
- eating carbs raises blood glucose
- start the cycle again
What does the normal cell do with glucose?
- insulin binds to the insulin receptor
- IRS-1 is recruited to the receptor
- IRS-1 begins a signal transduction cascade to tell the golgi complex to make GLUT-4
- GLUT-4 is translocated from the golgi complex to the plasma membrane
- glucose is able to enter muscle and adipcytes for use or storage
What does the insulin resistant muscle cell do with glucose?
- Insulin binds to the insulin receptor
- IRS-1 is recruited to the receptor
- excess inflammation (CRP-1) abnormally phosphorylates IRS-1, causing it not to signal properly
What does insulin tell the cell to do (depending on how much glucose there is)?
(least amount of glucose) use glucose for ATP
store glucose as glycogen in liver and muscles
(most amount of glucose) turn into adipose tissue
What happens when there is low blood glucose?
- Alpha cells from pancreas release glucagon
- glycogen gets broken down into glucose
- this stimulates glucocorticoids that inhibit glucose uptake by cells
- stimulates gluconeogenesis (AA–>glucose)
- increases glucose in blood to normal
What is hyperglycemia?
when the blood glucose is persistently too high
What are the different types of hyperglycemia?
prediabetic, diabetic
What are the symptoms of hyperglycemia?
frequent urination, dehydration, thirst
Why is frequent urination a symptom of hyperglycemia?
the kidneys can’t resorb all the glucose and it end up in the urine and it pulls a lot of water with it
Describe Type 1 diabetes.
insulin dependent, autoimmune disorder, need insulin injections
Describe Type 2 diabetes.
insulin independent, GLUT 4 problems, cause by poor diet and sedentary lifestyle, can be fixed by losing weight and eating healthier
When recommending lifestyle changes,
jmk,
How do you determine how many other carbs you are getting?
total carbohydrates - dietary fiber - sugar = other carb
Which kind of carbohydrate does NOT increase blood glucose?
dietary fiber
What are the different outcomes for glucose in the blood?
liver glycogen, kidney, other tissues for glycolysis, stored as fat, muscle glycogen
What is glycogen?
the storage form of carbs in mammals
What is the liver’s role in glucose maitenence?
reglulates blood glucose
How much time passes for the liver to be completely depleted of glycogen?
15 hour fast
What happens to the glycogen in the liver after 1 hour of aerobic activity?
50% of it is used
How much glycogen fills the liver?
400kcal or 100g
What does muscle do with glycogen?
uses it for excercise, can be doubled in trained muscles
What happens to glycogen once it enters the muscle?
it cannot be released from muscle once it is phosphorylated
How much glycogen can an untrained muscle hold?
350g or 1400kcal
How are proteins used in creating energy?
amino acids –> pyruvate –> acetyl CoA –> Krebs cycle, ETC–>CO2, H2O, ATP
How are carbs used in creating energy?
glucose –> pyruvate –> acetyl CoA –> Krebs cycle, ETC –> CO2, H2O, ATP
How are lipids used in creating energy?
glycerol –> pyruvate –> acetyl CoA –> Krebs, ETC –> CO2, H2O, ATP
OR
FA–> acetyl CoA–> Krebs, ETC –> CO2, H2O, ATP
How does adipose turn into glucose?
Triglycerides –> glycerol–> blood stream–> glucose
How does the muscle contribute to glucose creation in the liver?
protein –> glucogenic AA –> alanine–> blood stream–> glucose
OR
glycogen–>pyruvate–>lactate–>blood stream–> glucose
OR
glycogen–> pyruvate–>glucogenic AA–> alanine
OR
glycogen–> pyruvate–> blood stream–>glucose
What is the general role of carbs in the body?
fuel activity, spare protein
What kind of energy contributes to low intensity exercise?
lipids more than carbs
What kind of energy contributes to moderate intensity exercise?
carbs more than lipids
What kind of energy contributes to high intensity exercise?
carbs way more than lipids
Why are carbs preferred during high intensity exercise?
carbs are more efficient because they require less oxygen
How do endurance trained muscles differ from untrained muscles?
increase capacity for carb use
increases fat burning
store more glycogen in muscle
muscle glycogen synthesis is twice as fast in trained muscle
During exercise hypoglycemia, what decreases?
insulin so there is an increase in glucose transport into muscle cells
During exercise hypoglycemia, what increases?
GLUT 4 receptors, epinephrine, glucagon, cortisol
Why is GLUT 4 increased during exercise?
increases glucose transport into muscle
Why is epinephrine increased during exercise?
promotes liver glycogen breakdown
Why is glucagon increased during exercise?
promotes liver glycogen breakdown and stimulates gluconeogenesis
Why is cortisol increased during exercise?
promotes muscle breakdown for gluconeogenesis
When can you experience dizziness and partial breakout?
when the body is using more blood glucose than muscle glycogen
During exercise (after a while), where do you get glucose from?
liver glycogen and gluconeogenesis
During aerobic exercise, what makes the muscle fatigue?
low muscle glycogen stores
During anaerobic exercise, what makes the muscle fatigue?
low muscle glycogen stores, lactic acid production
Who carb loads?
swimmers, bicyclists, triathletes, marathoners, cross-country skiers