The document discusses protein and fiber needs for athletes. It recommends endurance athletes consume 1.2-1.4 g/kg protein daily and strength athletes consume 1.2-1.7 g/kg daily. While intakes up to 2.0 g/kg may support muscle growth, higher intakes are unlikely to provide benefits and could negatively impact hydration, nutrient quality, and health. The document also outlines different types of fiber, their physiological effects, health benefits including regularity and disease reduction, and recommends 25-38 g of fiber intake daily depending on gender.

1. Protein for Athletes
 American College of Sports Medicine (ACSM) /
American Dietetic Association (ADA)
–Endurance athletes, 1.2 to 1.4 g/kg per day
• Accounts for greater use of protein as fuel for energy
–Strength athletes, 1.2 to 1.7 g/kg per day
• To support muscle growth, particularly during early training phase when gains
are greatest and protein utilization is less efficient
 Clinical studies suggest there is no apparent
benefit at intakes above 2.0 g/kg per day

2. How much protein for athletes?
• Many athletes may already meet or exceed protein
recommendations
– Definition of “high protein” can be the absolute amount of
protein, % of total energy (calories), or protein ingested
per kg of body weight
• Strength athletes in particular may believe that much
higher protein intakes are needed for muscle building
– Intakes at 4- to 6-g/kg range are not uncommon
– Unlikely to provide benefit beyond 2.0 g/kg
– It is possible that this much protein intake could adversely
affect the nutrient quality of the overall diet

3. Risks of High Protein
 Hydration status
– Nitrogen that is obtained from consuming protein must be excreted in the
urine as urea
– Increased urinary output due to high protein load may increase chances of
dehydration
 Diets very high in protein may lack appropriate amounts
of carbohydrate, fiber, and some vitamins/minerals
– Could impair exercise performance
– Could increase long-term risk of diseases such as colon cancer
• Possibly due to lack of fiber or increased intake of red meat
 Excessively fatty protein sources could increase risk
of cardiovascular disease
– Choose mostly lean protein sources
• For example, salmon is more desirable than a ribeye steak

4. Branched Chain Amino Acids
• Make up 40% of the daily requirements of essential amino
acids

5. Branched Chain Amino Acids
 BCAAs are
 Unlike other amino acids, most BCAA
metabolism occurs in skeletal muscle
– Liver lacks first 2 enzymes in the pathway that break
down BCAAs
 Supplemental free form, bypass the liver and gut
and go directly into the blood stream.
 BCAAs inhibit brains ability to uptake tryptophan

6. Leucine
– The bodies need for leucine is 25 times greater than
the available free amino acid pool.
– Stimulates protein synthesis by activating insulin
– Insulin increases a.a. uptake
– Incorporation of BCAAs in muscle is IGF-1 dependent
– IGF-1 stimulates muscle synthesis
– Chronic low levels of BCAAs will show up in urine
– β-hydroxy-β-methylbutyrate (HMB) is derived from the
breakdown of leucin
– Some evidence in humans that doses of 3 g/day may
be effective at preventing muscle breakdown
• Additive benefits with creatine
– Some studies suggest that HMB may provide greater
benefit to untrained people who start weight training
compared with previously conditioned athletes

7. Should athletes Supplement?
 If protein requirements are met, the individual AA
requirements should be met as well
 Estimated that 3-18% of workout energy is provided by
BCAAs
 Leucine increases release of fats for energy
 Claims mainly center on decreasing muscle soreness and
improving either performance or recovery from exercise
 Doses can range from 2 to 7 g/day to more than 20 g/day
taken before during and after
 There are potential risks associated with AA supplements
– Large doses of single AAs can prevent the absorption of other AAs, which may
lead to diarrhea
– Can indirectly cause deficiency of other AAs as a result

8. Phosphocreatine
• aka creatine phosphate (PCr)
• Rapidly mobilizable reserve
of high energy phosphate for
skeletal muscle (and brain)
• Formed from parts of Arg,
Gly & Met
• Can donate phosphate to
ADP anaerobically in the first
2-7 seconds following an
intense muscular effort
• Forward and reverse reaction
catalyzed by CK, which is a
marker of muscle damage

9. Alcohol
• Ethanol
• Not a nutrient
• 7 kcal/g
• 50% alcohol = 100 proof

10. Alcohol Absorption
• Small amounts absorbed
in mouth and esophagus
• 20% absorbed directly
across stomach wall
• Food delays diffusion
• Most absorbed by simple
diffusion in the upper
small intestine
• Distributed wherever
water is found

11. Alcohol metabolism
1) Alcohol Dehydrogenase System
- women have less
- varies among ethnic groups
- NADH production turns of TCA cycle
- Excess acetyl CoA converted to FATTY ACIDS
- Fatty liver develops

12. 2) Microsomal Ethanol-oxidizing
System (MEOS)
• When ADH cannot keep up with demand
• Occurs in liver, in cytosol of cells
• Also used to metabolize drugs and foreign substances
• Reduces bodies ability to detoxify drugs  overdose
• Increases alcohol metabolism, thus tolerance  leads to weight
loss

13. 3) Catalase Metabolism of Alcohol
• Found in liver
• Minor pathway for alcohol metabolism
Ethanol Acetaldehyde
H2O2 H2O
Catalase

14. Alcohol Metabolism
• Depends on:
- Sex
- race
- size
- food
- physical condition
- alcohol content
• Amount of alcohol
dehydrogenase
• Alcohol cannot be
stored and has priority
in metabolism

16. Negative effects on vitamins and
minerals
• Thiamin
• Niacin
• B6
• B12
• Folate
• Vitamin C
• Vitamin A
• Vitamin D
• Vitamin K
• Vitamin E
• Magnesium
• Zinc
• Iron

17. Alcoholics and malnutrition
• Poor diet
• Alcohol has energy but no nutrients
• Lack of interest in food: GI problems
• Alcohol interferes with absorption of amino
acids
• Alcohol races blood level of fats

18. Liver Damage
• Build up of
acetaldehyde
• Production of free
radicals
• Alcohol inhibits
body’s natural
antioxidant systems
• Advanced stages of
liver damage are
not reversible

19. Fetal Alcohol Syndrome
• Alcohol reaches fetus
• Deprives brain of
oxygen and nutrients
• About 4 drinks a day or
binge drinking while
pregnant
• Prenatal and postnatal
growth retardation
• Brain and CNS
impairment
• Abnormalities of face
and skull
• increased rate of birth
defects

20. Health Benefits of Alcohol
• Moderate drinking
associated with reduced
mortality
• ≤ 2 drinks for men, ≤ 1
drink for femal
• Reduced cardiovascular
disease
-reduces blood clotting
-increase HDL
-reduced inflammation
• Polyphenols
• Relaxation and
socialization

21. Fiber
• Plant cell wall contains > 95% of dietary fibers
- cellulose, hemicellulose, lignin, pectins
-Lignin  structural support
-Pectin  intercellular cement
-Cereal bran  hemicellulose and lignin
-Fruit & Vegetables  cellulose and pectin
• Starch  energy storage is found within the
cells walls

22. Fiber = ability to resist digestion
in the small intestine

23. Fiber
Dietary + Functional = Total Fiber
• Dietary – Found natuRally in foods
• Functional – forms added to foods
• Insoluble – Not fermented by bacteria
in the colon
• Soluble – Fermentable

24. Fiber
Soluble Insoluble
• Pectin
• Gums
• Mucilages
• Some
hemicellulose
• Lignin
• Cellulose
• Some
hemicellulose

25. Polysaccharides
1. Cellulose
• Polysaccharide of glucose
• Most abundant substance
in plant kingdom
• Β- 1,4 glycosidic linkages
• Water insoluble
• Does not provide energy
• Bran, legumes, nuts peas,
root vegetables, cabbage
• Cotton is pure cellulose

26. Insoluble fibers – Exterior/hulls &
Structural
2. Hemi-cellulose
• Mixture of
pentoses &
hexoses
• Linked to lignin
in cell wall
• Amorphous
• Partially soluble
in mild alkali
3. Lignin
• Highly branched
• Not digested by
colonic bacteria
• Non-CHO
• Structural support
• Roots vegetables,
carrots, wheat,
fruits with seeds

27. Soluble Fibers – inside & around plant
4. Pectin
• gel forming
• Amorphous
• Intracellular cement –
spaces b/w cell wall
• Almost completely
metabolized by colonic
bacteria
• Apples, strawberries &
citrus
• Added jellies & jams
5. Gums/Mucilages
• Secreted at the site of
plant injury: tree
exudates
• Highly branched
• Highly fermented by
colon bacteria
• Gum arabic is a food
additive for gelling
• Caramels, gumdrops,
toffee, bakery goods,
salad dressings, oatmeal

28. Physiological & Metabolic Effects
Effects of Fiber
1. Solubility in water
• delay gastric emptying
• Increase transit time
• Decrease nutrient absorption
2. Water-holding capacity
• Delay gastric emptying
• Reduced mixing of GI contents w/ digestive
enzymes
• Delayed nutrient absorption
• Shortened transit time

29. 3. Ability to bind (adsorption) molecules
• Decreased absorption of lipids
• Increased bile excretion
• Lower serum cholesterol
• Altered mineral balance
4. Fermentability by intestinal bacteria
• Microflora produces SCFAs
- energy
- cell proliferation
-increases water absorption in the colon
Physiological & Metabolic Effects
Effects of Fiber

30. Soluble Fiber Fermented SCFA
• Acetic acid
• Butyric acid
• Proprionic acid
Fuel for cells
≈1.5-2.5 kcal/g
Blood stream
CO2, H2, CH4

31. Pre & Pro – biotic Diets
Medical Nutritional Therapy
• Pro-biotic
- ingestion of certain foods with live cultures containing
certain strains of bacteria to increase the counts of
specific microflora of the GI tract
-Yogurt
-survive digestion and then colonize lower GI tract
• Prebiotic
-food ingredients that are not digested or absorbed but
can stimulate the growth/activity of selected types of
bacteria in the colon
- Oligofructose or inulin (non-digestible oligosaccharides)

32. Health benefits of Dietary Fiber
• Promotes softer, larger stool and regularity
• Slows glucose absorption
• Increases satiety
• Reduces blood cholesterol
• Reduces heath disease
• Reduces hemorrhoids and diverticula

33. Nutrition and GI disorders
• Constipation
- reduced by fiber, fluid intake, exercise
• Diarrhea
• Diverticulosis
- Pouches along colon
- high fiber diet reduces formation

34. Recommended Dietary Fiber Intake
• Adequate intake (14g/1000 kcal):
- 25 g/day for women
- 38 g/day for men
- US intake: 13-17 g/day
• Too much fiber (>60 g/day)
- require extra intake of fluid
- binds to some minerals (Fe & Zn)
- fill the stomach of young child quickly