Download Chapter 5: Nutritional Considerations

Chapter 5: Nutritional Considerations
Jennifer L. Doherty, MS, LAT, ATC
Academic Program Director, Entry-Level ATEP
Florida International University
Acute Care and Injury Prevention
Proper nutrition can positively contribute to:
• Strength
• Flexibility
• Cardiorespiratory Endurance
Performance vs. Food consumption
• Myths and Habits vs. physiological benefits
• Psychological vs. physiological considerations
Nutrition Basics
Nutrients
• Carbohydrates
• Protein
• Fat
• Vitamins
• Minerals
• Water
Roles
• Growth, repair & tissue maintenance
• Regulation of body processes
• Production of energy
Carbohydrates
• Body’s most efficient energy source
• Accounts for 55-70% of total caloric intake
• Carbohydrates include:
– Simple Sugars
• Monosaccharides = fruits, syrup and honey
• Disaccharides = milk sugar, table sugar
– Complex Sugars
• Starches = rice, potatoes, breads
• Fiber = oatmeal, legumes
Fats
• Most concentrated source of energy
• Essential for normal growth and development
• Saturated vs. unsaturated
– Saturated Fats
• Derived from animal products
– Unsaturated Fats
• plant derivatives - liquid at room temperature
Other Fats
• Phospholipids
• Sterols
– Cholesterol
– Consume <300mg/day
• Omega-3 fatty acids (unsaturated fat)
– Reduces risk of heart disease, stroke, hypertension
– Found in cold-water fish
• Fat Substitutes
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Simplese and Olean
Contain 80% fewer calories than fat
Contain no cholesterol
May cause abdominal cramping and diarrhea
Trans Fatty Acids
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Physical properties resembling fatty acids
Found in cookies, crackers, dairy, meat products, and fast foods
Increases level of bad cholesterol
No safe level of trans fatty acids
People should eat as little of them as possible
Proteins
• Required for growth, maintenance, and repair of the body
• Aid with enzyme, hormone, and enzyme production
• Should encompass 12-15% of daily caloric intake
Amino Acids
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Basic units that compose protein
Most can be produced by the body while others (essential) must be consumed
– Animal products contain all essential amino acids
– Incomplete sources (i.e. plants sources) do not contain all essential amino acids
Protein sources and needs:
• Most diets are rich in protein
– Athletes consume twice the recommended
• Excess protein is converted to fat
– May result in dehydration and potential kidney damage
• Increased physical activity results in increased need for protein in the
diet
Regulator Nutrients
• Vitamins (13) serve as regulators in many body processes
• Fat soluble
– Vitamins A, D, E , K
– Found in fatty portion of foods and oils
• Water soluble
– Vitamin C, B-complex vitamins
– Help to regulate metabolism but cannot be stored
• Anitoxidants
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May prevent premature aging, cancers, heart disease and other health problems
Help protect cells from free radicals
Include vitamins A, C, E
Found in a number of dark green, deep yellow and orange fruits and vegetables
Supplements
• Vitamin Deficiencies
– Illness that results from a deficit in a particular vitamin/mineral
– Are avoidable if an adequate diet is consumed
Minerals
• More than 20 minerals have essential roles in the body
• Many are stored in liver and bones
• Examples
– Iron = energy metabolism and O2 transport
– Calcium = bone formation, clotting, muscle contractions
– Sodium and Potassium = nerve conduction
Water
• Most essential nutrient
• Most abundant nutrient in body
– 60% of body weight
• Essential for all chemical processes
• Dehydration can lead to illness and death
• Body has mechanisms to maintain homeostatic levels of hydration
(electrolyte balance)
Nutrient Requirements and Recommendations
• Amount of nutrient required to prevent deficiency diseases
Requirements vs. Recommendations
• RDA (Recommended Daily Allowance)
• DRI (Dietary Reference Intake)
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RDA
UL’s (upper intake levels)
EAR (estimated average requirements)
AI (adequate intake)
Food Labels
• Aids consumers in determining levels of nutrients in foods
The Food Guide Pyramid
• Used to educate Americans on the relationship of food choices to health
• Illustrates food groupings and minimum number of required servings
Nutrition and Physical Activity
• Activity increases need for energy
• Does not necessarily increase the need for fat, vitamins, and/or minerals
• Vitamin Supplementation
– Athletes believe large doses can lead to superior health and performance
Common practices:
Vitamin Supplementation
Vitamin C
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Thought to prevent the common cold and slow the aging process
May cause kidney stones and diarrhea
Vitamin E
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Protects cell membranes from damage
Little evidence to support enhancing performance or life expectancy
B-complex vitamins
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Aid in release of energy from CHO, fat, and protein
If additional energy is required, increased caloric intake is necessary
Common practices:
Mineral Supplementation
• Calcium and iron tend to be low
– Diets may need to be modified
– Milk products are the most reliable source of calcium
• Need to be certain additional minerals are necessary in diet prior to
purchase
– Save money
Calcium Deficiency
• Ca is the most abundant mineral in body
• Over time, additional levels of Ca++ are required for bone maintenance
++
– Without Ca++ bones become weak and brittle resulting in osteoporosis
• Young adult requires 1000mg/day
– Females tend not to get enough Ca++ in diet
• Exercise helps bones retain Ca++
– Extreme levels of exercise causing hormonal imbalances can disrupt Ca++ retention
Calcium Supplementation
• Supplementing with calcium carbonate or citrate is advisable
• Some athletes complain it causes upset stomach due to a build up of
intestinal gas
– May be lactose intolerant and lack the enzyme lactase
– Can supplement with lactase
• Scientifically produced
Iron Deficiency
• Common in females
• Results in iron-deficiency anemia
– Limits oxygen carrying capacity of blood
• Athlete feels tired and weak due to muscles’ inability to generate energy
• Iron supplementation may be used
Protein Supplementation
• Approximately 1-1.5g/kg body weight of protein should be consumed for
increasing muscle mass
• Often times exceeded with normal diet and supplementation is not
necessary
Creatine
• Naturally occurring substance in body produced by kidneys, pancreas
and liver
• Found in meat and fish
• Role in metabolism
• Phosphocreatine is stored in skeletal muscle and works to re-synthesize
ATP during activity
Creatine Supplementation
Positive effects
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 intensity of workouts
lactic acid buffer
stimulates protein synthesis
 total cholesterol and total triglycerides and improves HDL-LDL ratio
 fat free mass
Negative effects
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weight gain
muscle cramping
gastrointestinal disturbances
renal dysfunction
Caffeine
• Found in carbonated beverages, coffee, tea
• Central nervous system stimulant
– Increases alertness and decreases fatigue
– Too much causes nervousness, irritability, increased heart rate and headaches
• Headaches may result when ceasing caffeine use
• Not detrimental to performance
– Enhances fat utilization and endurance performance
– Makes calcium more available allowing muscles to work more effectively
Alcohol
• Provides energy for the body
• Little nutritional value
• Central nervous system depressant
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decreases coordination
slows reaction time
decreases mental alertness
increases urine production (diuretic effect)
Ephedrine
• Stimulant used in diet pills, illegal recreational drugs, and legitimate OTC
medications
• Similar to amphetamine
• Adverse reactions
– Heart attack, stroke, tachycardia, paranoid psychosis, depression, convulsions, fever, coma,
vomiting, palpitations, hypertension, respiratory depression
Pre-event Nutrition
Note: Long term food consumption is more important than immediate
consumption
• Purpose = provide competitor with nutrients/energy and fluids for
competitions
– Taking digestibility into consideration
• Diets should be individualized
• Important consideration:
– Food takes ~4 hours to clear stomach and upper GI tract
Pre-event Nutrition
Liquid Supplementation
• Extremely effective and successful
• 225-400 calories per serving
• Successful in reducing pregame symptoms of dry mouth, abdominal/leg
cramps, nervous defecation, and nausea
Post-Event Nutrition
Eat nutrient rich carbohydrate foods!
• When the time period between events is <8 hours
– Consume CHO immediately to maximize recovery
– Consume 0.45-0.55 grams of CHO per pound of body weight for each of the first 4 hours
• For a 24 hour time period between events
– Consume 2.3 – 5.5 grams of CHO per pound of body weight
Complete restoration of CHO stores requires 20-24 hours
Weight Control and Body Composition
• Weight gains and weight loss can be problematic for athletes
• Ideal body weight = age-related height/weight chart
– Inaccurate due to broad ranges and failure to take individual body types into
consideration
• Body composition = fat vs. nonfat components of body
Body Composition
• Non-fat component of body = lean tissue
– Bone, muscle, tendon, connective tissue
– Called lean body weight
• Body composition is the relationship between fat tissue and lean tissue
• Averages:
– Female 20-25% body weight = fat
– Male 12-15% body weight = fat
Body Composition
• Overweight = excess body weight relative to size and stature
• Overfat = excessively high percentage of total body weight that is fat
• Obesity = extreme amount of excessive fat
– Female >30% and male >20% percent body fat
Factors that determine the amount of fat:
• (1) Number of cells
– Proliferation or hyperplagia of fat cells
– Occurs from birth to puberty
• (2) Size of cells
– Increase/decrease over time until adulthood
– Relative to caloric balance
• (3) Change of weight = change in size, not number
• Moderate, long term activity uses the greatest amount of fat to meet energy
demands
– One pound of fat = 3500 calories
Assessing Body Composition
• Several methods
– Hydrostatic, bioelectrical impedance, skinfold thickness measures
• Skinfolds based on the fact that 50% of body fat is subcutaneous
– Utilize skin fold calipers
– Relatively low accuracy but is easy to learn and utilize
– Error is + 3-5%
• Hydrostatic Weighing
– Utilizes underwater tank to determine body density
– Establishes relationship between lean mass (more dense) and fat mass (resulting
in more buoyancy)
– Very accurate method
– Not always available, expensive equipment
– Time consuming
– Requires exhaling all air
• Bioelectrical Impedance
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Measures resistance of electrical current flow between points
Based on principle that electricity will flow through path of least resistance
Fat = good insulator
Water = good conductor
Impacted by levels of hydration
Expensive equipment
Determining Body Mass Index
• Determine extent of overweight or obesity
– BMI = ratio of height and weight
• Utilized to measure health risks associated with obesity
– BMI > 25 indicate excess body fat
– BMI 25-30 indicates overweight
– BMI > 30 indicates state of obesity
Assessing Caloric Balance
Caloric balance = Calories consumed - Calories expended
• Positive caloric balance = weight gain
• Negative caloric balance = weight loss
• May be calculated through accurate record keeping
– Calories consumed vs. Calories expended
– Calories are expended through:
• Basal metabolism (calories expended at rest) = BMR
• Work (activity that requires more energy than sleeping)
• Excretion
Methods of Weight Loss
• Dieting results in loss of lean body tissue
– Women should not drop below 1000-1200 calories
– Men should not drop below 1200-1400 calories
• Exercising results in loss of fat mass
– Will also enhance strength, cardiorespiratory endurance, and flexibility
Methods of Weight Loss
Moderation, Moderation, Moderation!!!
• A combination of dieting and exercise is essential
• A negative energy balance must be achieved
• Loss of 1.5 - 2.0 pounds per week is adequate
– Weight loss of more than 4-5 pounds per week can be attributed to dehydration
Methods of Weight Gain
• Goal = increase lean body mass
• Methods to increase lean body mass
– Increased physical activity (muscle work)
– Dietary modifications
• Approximately 2500 calories is required per pound of lean body mass
– Consume additional 500-1000 calories per day
• A 1-2 pound per week gain in lean body mass is adequate
Disordered Eating
• Spectrum of abnormal eating habits
– Mild food restriction, binging, purging, bulimia, anorexia nervosa
• Multi-factorial
– Social, familial, physiological, psychological components
Disordered Eating
• Abnormal eating behaviors, ranging from mild food restriction and occasional
binging and purging, to severe conditions (eating disorders)
• More prevalent in athletic populations
– Control over body weight/composition for performance
Eating Disorders
– Bulimia
– Anorexia Nervosa
– Anorexia Athletica
Bulimia
• Periods of starvation, bingeing (thousands of calories) and purging
through vomiting, fasting and laxatives/diuretics
• Generally affects females ranging in age from adolescence to middle age
Characteristics:
– Typically bulimic athletes are white, middle to upper-middle class
– Perfectionist, obedient, over-compliant, highly motivated, successful academically, well-liked,
and a good athlete
– Gymnastics, track, dance
• Occasionally seen in male gymnasts and wrestlers
• Bingeing and purging can result in stomach rupture, heart rhythm, liver
damage, tooth decay from acids, chronically inflamed mucous lining of
mouth and throat
Anorexia Nervosa
• Distorted body image and constant concern about weight gain
• 30-50% also suffer from bulimia
• Impacts mostly females
• Starts often with adolescents and can be life threatening
Characteristics:
• Continue to feel fat when too thin
• Deny hunger sensations
• Hyperactive
• Highly secretive
Anorexia Athletica
• Condition specific to athletes
• Similar to anorexia nervosa; however, no self-starvation
Characteristics:
• Disturbance of body image
• Weight loss >5% of body weight
• Gastrointestinal complaints
• Primary amenorrhea
• Menstrual dysfunction
• Absence of illness explaining weight reduction
• Fear of becoming obese
• Binging, purging, compulsive eating, or caloric restriction
Female Athlete Triad
• Potentially fatal problem
• Combination of eating disorder, amenorrhea and osteoporosis
– Bone lost may not be regained
• Eating disorders exist in 62% of females in certain sports
– Amenorrhea found in 60% of female athletes
Treatment for Eating Disorders
• Early intervention is critical!!
– Empathy is a must
• Psychological counseling is key
• Keys to successful treatment:
– Must recognize the problem
– Must accept the benefits of assistance
– Must voluntarily accept help