Lecture 2: Macronutrients Flashcards
What are the macronutrients?
Proteins
Carbs
Fats
What is the kcal per macronutrient?
Carbs/proteins are 4 kcal/gram
Fats are 9 kcal/gram
What is a carb?
Organic compound made of carbon and water in a 1:1 ratio.
What do carbs lack?
No fatty acids
No amino acids
Where are carbs the majority of matter?
Plant matter
Why do we like carbs?
Readily usable energy. It is the primary source.
What % of calories are made up of carbs in a typical diet?
40-70%
What are the major functions of carbs?
Fuel for metabolic processes (ESP CNS, RBCs, and renal medulla)
Prevent protein breakdown for energy
Enable fat metabolism/oxidation
Taste/dietary variety
Healthy gut (our gut flora needs the fiber to eat)
Help form important cellular structures
What are the simple carbs?
Monosaccharides: glucose, fructose, galactose.
Disaccharides: sucrose, lactose, maltose
What is found in every simple carb?
Glucose.
What are the complex carbs?
Polysaccharides: Starches, cellulose, glycogen, gums, pectins
What are the primary starches in a human diet?
Amylose and amylopectin
What is glycogen?
Storage for glucose in ANIMALS.
What are the two types of fiber?
Soluble fiber, which dissolves in water and makes a gel-like material
Insoluble fiber, which stays intact and increases stool bulk.
What is fiber?
A resistant starch that is not absorbed or digested.
What is the recommended fiber intake?
30-38g for males
21-25g for females
Why do carbs need to be broken down?
Our body can only absorb monosaccharides in the GI tract.
How are carbs brokwn down?
Amylase from the salivary glands and pancreas.
Where are monosaccharides absorbed and moved?
Absorbed in the SI.
Moved to the liver.
Why do monosaccharides end up at the liver for processing?
It can covert all monosaccharides to glucose.
It can convert excess glucose into glycogen to store.
It can covert excess glucose to TG/fats if glycogen is full.
Why are complex carbs better to eat?
Increased satiety due to the longer breakdown time.
What is the impact of fiber on blood sugar/energy?
None.
What is glycemic index?
Evaluates the 2-hour postprandial curve for BG values relative to a reference standard
What is glycemic load?
Similar to glycemic index, but it takes into account the standard serving size of the food.
What kind of pts can really benefit from a low GI/GL diet?
Chronic disease pts, esp. those with HTN, DM, cancer, CV disease, or obesity.
What is generally considered low GI?
Anything under 55, aka veggies, whole grains, low-fat stuff.
What is the recommend carb intake in terms of %?
45-65% of carbs.
What are the clinical pearls for pt education regarding carbs?
Less processed is generally more healthy.
White foods are generally unhealthier.
Fiber is your friend.
Avoid eating carbs without protein or fat.
Type of carb is more important than the amt.
Avoid sugary beverages
What are dietary fats?
Water-insoluble lipids.
Where do dietary fats come from?
Plants AND animals
What essential thing do dietary fats contain?
Essential amino acids.
What countries have high dietary fat intake?
Some european countries and the US.
Why is consuming excess fat so easy to do?
It has a low satiety index.
It feels less filling but has the highest calorie/gram.
What are the major functions of dietary fats?
Energy reserve
Adipose tissue (you can store extremely high amts of kcal in adipose tissue)
Absorb necessary fat-soluble vitamins (DEAK)
Provide the essential AAs (linoleic and alpha-linoleic acid)
Component of body structures and molecules
Insulate
Cushioning
Flavor
What are saturated fats more likely to be at room temp?
Solid.