Macronutrients Flashcards
2 Types of Carbs, Examples, & Characteristics
Simple carbs
Ex - Sugar
Digested quickly for fast energy
Complex
Ex - starches/fiber
Digested slowly or not at all
Monosaccharides (5)
- Glucose - vital fuel source for body
- Galactose - found in combo w/ other sugars; broken down by liver and converted into glucose
- Maltose - produced during breakdown of plant starches
- Sucrose - sugar beets, sugar cane, gran sugar
- Lactose - sugar in dairy
Resistant starches
Some starches cannot be broken down in small intestine. Will land in colon (?) and fermented/metabolized by gut bacteria to nourish the microbiome
Why can’t our body break down fiber (cellulose)?
In fiber/cellulose, two beta-glucose molecules bind and that bond crosses a plane and our body does not have the enzymes to break that link down.
Starch
stored form of energy found in plant foods
Foods high in starch
tubers, root vegetables, winter squash, cereal grains (rice, corn), grain, flour-based products (bread, pasta)
Food sources of resistant starch
oats, rice, beans and legumes, potatoes, green bananas, plantains
Two types of fiber and their functions
Soluble - dissolve in liquid (pectin, mucilage, gums); slows down movement of food through digestive tract leading to a more gradual absorption of glucose (reducing spikes/dips) and can feed the good bacteria in the microbiome
Insoluble - do not dissolve in liquid; causes food to move faster through GI tract, adds bulk to stool (helps with constipation)
Many plant foods contain a variety!
Foods high in soluble fiber
apples, pears, legumes, oats, dried apricots, dates, sweet potato, cruciferous vegetables, flaxseed, chia seed, psyllium husk
Foods high in insoluble fiber
wheat germ and bran, beans, legumes, whole grains, berries, edible skins of fruits and vegetables, leafy greens
Carbohydrate function
accessible source of fuel for energy production, particularly for the brain and muscles; once immediate needs are met, glucose contributes to stored energy in the body (liver) as triglycerides which will be stored as body fat
Carbohydrate deficit and muscle tissue relationship
In the absence of adequate carbohydrate intake, the body will break down protein in muscle tissue to make glucose to fuel energy pathways
Glycemic Index overview and limitations
-GI is a numerical reference to classify carbs based on the degree to which they increase blood sugar after eating
-Foods are ranked on a scale of 0-100 (100 = white bread)
Limitations:
1. GI values don’t account for how many grams of carbs are in a standard serving
2. GI value alone can wrongly malign otherwise healthy foods
Glycemic Load
the glucose effect produced by a standard serving of food rather than a fixed amount of carbohydrate
Better alternative to glycemic index
Dangers of long-term low-carb diet
constipation, fatigue, compromise to healthy gut flora, nutrient deficiencies, increased risk for osteoporosis, heart disease, and stroke
