ns425 u3summary
DESCRIPTION
Unit 3 SummaryTRANSCRIPT
CarbohydratesUnit 3
Stacey Day, MS, RD, LDN
Explain the basic structure and classification of carbohydrates
CHO Classification
Simple CHOs◦ Simple sugars◦ Monosaccharides◦ Disaccharides
Complex CHOs◦ Oligosaccharides◦ Polysaccharides
Photos © Photodisc
Other Polysaccharides Dietary Fiber
◦ Nondigestible◦ Plant sources◦ Soluble versus insoluble
Functional Fiber◦ Nondigestible◦ Commercially produced or isolated
form Dietary + Functional = Total Fiber
Photo Courtesy of Renee Comet/ National Cancer Institute
Artificial Sweeteners
Classified as:◦Non-nutritive◦Nutritive
Generally sweeter than sucrose Must have FDA approval Have “GRAS” status
Artificial Sweeteners
Aspartame◦ NutraSweet
Sucralose◦ Splenda
Saccharin◦ Sweet ‘n Low
Acesulfame-K Tagatose Sugar alcohols
Importance of CHO in Exercise
Serves as an energy source both at rest and during exercise.
Becomes sole source of energy during very intense exercise.
However, stores of CHOs in body are limited.
Importance of CHO in Exercise
Blood glucose levels and the amount of CHO (i.e., glycogen) stored in the muscles can delay fatigue.
What should an athlete eat in the days leading up to competition?
Well-balanced diet in which 55 to 70% of total calories come from CHOs.
Carbohydrate loading?
Photo © Digital Stock
What should an athlete eat in the hours leading up to competition?
0 to 4 hours prior to competition◦Small meal, easily digested, low fiber
◦Low glycemic index Liquid meals Fruit juices Photo © Able Stock
What about CHO consumption during competition?
Types of CHOs◦ Glucose, glucose
polymers, starches◦ Sport nutrition
products Gels Bars Drinks
Photo © Photodisc
What about CHO consumption during competition?
Amount of CHO◦ Depends on rate of
utilization◦ Length of
competition◦ ~60 grams/hour
Photo © Photodisc
How much should an athlete eat after competition?
.5 g of CHO/lb:◦ Immediately after◦ 2 hours after◦ 4 to 6 hours after
Photos © Photodisc
Glycemic Index versus Glycemic Load
Glycemic Index (GI)
Glycemic effect of an isolated food
Based on elevation of blood sugar levels two hours after ingestion
Glycemic Load (GL)
Glycemic effect of the diet
(GI x CHO content per serving) x 100
How useful are GI and GL in sport?