Balanced diet and optimum weight Flashcards
What is a balanced diet?
The combination and proportion of carbohydrates, fats, proteins, roughage, water, and essential vitamins and minerals which best provide a sportsperson’s nutritional requirements.
Carbohydrates - function as a food fuel
> Main energy provider
Broken down into glucose
Transported as an immediate energy source
Excess stored in muscles and over as glycogen
Carbohydrate sources
Pasta, rice, potatoes, sugars
Carbohydrate % in a balanced diet
60%
Fats - function as a food fuel
> Secondary energy supply
For long duration, low intensity aerobic exercise
Absorbed as fatty acids and glycerol in small intestine
Stored as triglycerides in adipose tissue
Provides energy when glycogen stores are depleted
Useful for insulation
Fats sources
Butter, oil, confectionary, cheese, pastry
Unsaturated - avocados, nuts
Fats % in balanced diet
20-25%
Proteins - function as a food fuel
> Absorbed as amino acids in the small intestine
Aids tissue repair and recovery from intense exercise
Energy source when CHO and fats are depleted
Protein sources
Meat, eggs, milk, cheese, nuts
Vitamins - function as a food fuel
> Organic substances needed for crucial bodily functions
Regulate metabolism
Facilitate energy release
Bone formation and tissue synthesis
Vitamin C and D
Maintain the immune system and strengthen bones
Vitamin E
Prevents oxidative damage that occurs during endurance events
Vitamin K
Regulates blood flow, aiding transport of O2 to working muscles
Vitamin sources
Fruit, whole grains, seeds
Vitamin % in a balanced diet
Small amounts are essential
Minerals
> Calcium
Iron
Magnesium
Sodium
Calcium
(Milk)
> Structure in bones and teeth
> Bone regeneration and protection
Iron
(Red meat, spinach)
> Red blood cell production
Magnesium
(Beans)
> Counteracts amount lost during sweating
Sodium
(Cheese)
> Maintains electrolyte balance, improving cell maintenance
Minerals % in balanced diet
Small amounts essential
Roughage (Fibre) - function as a food fuel
> Gives bulk to food residues in intestines
Aids gastrointestinal functions
Effective digestion
Prevents overeating
Roughage sources
Brown rice, nuts, potatoes, bran cereal, vegetables
Roughage % in balanced diet
Large amounts necessary
Water - function as a food fuel
> Transports nutrients
Leaves the body in urine and faeces
Lubricates joints
Water needs during performance
> Performance decreases when an athlete is dehydrated by 5% of their body weight
Leads to dizziness, headaches, increased body temperature, increased heart rate
Additional water should be consumed
Water % during balanced diet
Large amounts necessary
Body Mass Index
A measure that uses our height and weight to work out if your weight is healthy
BMI equation
BMI: weight (kg) / height (m2)
Energy balance
Energy input : Energy expenditure
Male and female calorie requirements
Male: 2500 / day
Female: 2000 / day
Positive energy balance
Energy intake > Energy expenditure
What is the cause of positive energy balance
> Inactivity
Too much fat intake
CHO and excess fat are converted into fatty acids and glycerol, then stored as triglycerides
Results of positive energy balance
Health conditions:
> Coronary heart disease
> Hypertension
Negative energy balance
Energy intake < energy expenditure
Why might an athlete want to create a positive energy balance?
Gain body mass
> Sumo wrestler
> Higher intake than expenditure
> Helps them to gain fat
> Making it more difficult for their opponent during competition
Why might an athlete want to create a negative energy balance?
Lose body mass
> Jockey
> Higher expenditure than intake
> Lose weight, lighter
> Increase speed on horse
Basal Metabolic rate
The rate at which the body uses energy while at rest to maintain vital functions (such as breathing)
Factors that raise BMR
> Eating frequent meals - digestion requires energy
Exercise
Muscle mass - muscle requires more energy than other tissues
Age
Height
Pregnancy
Environment - extremes in temperature
Factors that lower BMR
> Age
Fasting/starvation
Sleep
Hormones
Optimum weight
The weight someone should be based one sex, height, bone structure, and muscle girth
(differs by sport and position)
Optimum weight - sex
Men
- heavier bone structure
- bigger muscle girth
Optimum weight - height
Tall people weigh more
Optimum weight - muscle girth
Bigger muscles weigh more
Optimum weight - bone structure
Heavier bones weigh more