Nutrient can be classified into macronutrient and
micronutrient.
- Macronutrients : daily requirement of the nutrient is more than 1 g / day such as carbohydrate, protein and fat.
- Micronutrients : daily requirement of the nutrient is less than 1 g / day such as itamin and mineral.
Calorie providing nutrient including carbohydrate,
protein and fat while non energy providing nutrient include vitamin, mineral
and water.
MACRONUTRIENTS
Carbohydrate
The majority of carbohydrate in the diet come from
plants, an exception being milk. Carbohydrate are the most importance source of
energy in the diet, being the primary energy source for exercising muscles, the
brain and central nervous system. Carbohydrates are classified according to
their structure into simple or complex carbohydrates.
- Primary source of energy that provide glucose necessary for glycogen stores.
- 1 g CHO = 4 kcal
- CHO should contribute 55% – 70% from total energy intake
- Recommendations: 6-10 g/kg body weight/day
- Optimum CHO needs depend on:
- Total energy
- Body size
- Duration, intensity and type of exercise
- Glycemic Index ( a factor that rank food from 0 to 100 based on the rate at which a food raises the blood glucose level.
Types: sample and complex
Source of
Carbohydrate
Situation
|
CHO
Recommendation
|
Low intensity @ training program less than 60-90 min/day
|
5-7 g/kg body weight/day
|
Training program more than 90-120 min/day
|
7-10 g/kg body weight/day
|
Extreme exercise program in between 6-9 hours/day (cross country
cyclist
|
10-12 g/kg body weight/day
|
CHO loading for endurance & ultra endurance athletes
|
7-10 g/kg body weight/day
|
Rapid recovery after training session @ competition multiple day
(duration in between session is less than 8 hours)
|
1 g/kg body weight (the first 30 min
after competition) repeat intake of 1 g/kg body weight every 1-2 hours until
actual requirement achieved
|
- Complex CHO or starches include rice, bread, pasta, sweet corn, pulses, potatoes, animal muscle and liver.
- Carbohydrate recommendation according to situation.
Protein
Protein is needed to build and maintain all the
cells in the body, a unique function that no other nutrient can fulfill. Cells
are constantly being replaced and an intake of protein is therefore needed on a
daily basis. During periods of growth and development there is an additional
need for protein hence, children and adolescents will have a proportionally
greater requirement than adults.
If carbohydrate and fats are not eaten in
sufficient amounts, protein can be used to meet energy demands. Protein cannot
be stored for later use like carbohydrate and fat, so if more protein is
consumed than the body needs for growth, maintenance and repair, the excess
protein is either broken down and used for energy or converted into fat and
stored.
Proteins are made up of amino acids linked together
in long chains. The body needs 20 different amino acids for its structure and
function. Eight of these amino acids are essential, cannot be made by the body
and must therefore be provided by the diet.
Functions:
- Growth and maintenance
- Structural components
- Enzymes
- Hormones
- Antibodies
Types: Complete and incomplete protein
Requirement:
- Sedentary adults – 0.8 g/kg bw
- Active adults – 1.0 g/kg bw
- Endurance athletes – 1.2 to 1.4 g/kg bw
- Strength athletes – 1.4 to 1.8 g/kg bw
Sources of
protein
- Animal sources include meat, offal, poultry, fish, shellfish, eggs, milk and milk products.
- Vegetable source include beans, peas and lentils, nuts and seeds, tofu, soya and soya milk, textured vegetable protein.
Fat
Dietary fat is a vital nutrient and should be
included in the diet. Although a large percentage of the population consumes
too much fat, it is both unnecessary and unhealthy to try to exclude fat
totally from the diet.
- Recommendations: Endurance athletes: 20-25% of energy athletes, trying to lose weight : 20% of energy.
Visible fat include butter, margarine, ghee, oils,
cream, fat on meat and poultry skin.
Invisible fat include fat present in all but the
very lean cuts of meat, whole milk, eggs, meat products, chips, fried food and
pastry, salad cream, chocolate and creamy sauces.
The different
types of fats in the diets
Dietary fats are made up of different mixtures of
fatty acids which may be saturated, monounsaturated or polyunsaturated. Fat
containing a high proportion of saturated fatty acids tend to be solid at room
temperature while those that contain high proportions of unsaturated fatty
acids are usually liquid at room temperature.
Saturated fats e.g. meat and poultry, dairy
product.
Monounsaturated fats e.g. olive oil, peanuts,
almonds, avocado, pears, rapeseed oil.
Polyunsaturated fats e.g. sunflower, corn, soya
bean, cottonseed and safflower oils, only fish and lean meat.
Essential fatty acids which the diet must supply
include the omega-6 (linolenic acid) and omega-3 (alpha linolenic acid). The
are vital for the development of cell membranes and are involved in the
regulation of immune responses and blood clotting.
Cholesterol is an essential part of cell membranes.
It is involved in protecting nerve fibres and plays a role in the production of
vitamin D. Dietary sources of cholesterol are of animal origin only, namely egg
yolks, liver and kidney, fish roes and shellfish. However, the main source of
cholesterol in the blood is not directly from diet cholesterol. Cholesterol is
made in the liver and high intakes of saturated fats are associated with
increased levels of blood cholesterol. A raised level of blood cholesterol is a
risk indicator for heart disease.
MICRONUTRIENT
Vitamins and minerals are found naturally in food
and are vital in the maintenance of all body functions. They help to maintain
health and prevent disease. Different foods supply different vitamins and
minerals in varying amounts and therefore a wide range of foods must be
includes in a diet if requirements for these essential nutrients are to be met.
The Recommended Nutrient Intakes (RNI) Malaysia (NCCFN,2005) provides the
amount of nutrient that is sufficient for almost every individual. If an
individual consumes the RNI of a nutrient, that person is most unlikely to be
deficient in that nutrient.
Vitamins
Vitamins do not provide energy, although some are
involved in the release of energy from food. The requirements, functions and
food sources of water-soluble and fat-soluble vitamin are as follows:
Water Soluble Vitamins
Vitamins
|
Recommendations
|
Functions
|
Food
Sources
|
Vitamin
B1 (Thiamin)
|
1.0
1.5 mg
|
Needed in
energy metabolism and growth. Supports
muscle, nerve and cardiovascular function
|
Fortified cereals,
legumes nuts, organ meats, molasses and yeast.
|
Vitamin
B2 (Ribofalbin)
|
1.2 -1.7
mg
|
Essential for
energy metabolism; growth and tissue repair
|
Cereals, liver,
milk, green leafy vegetable, nuts, whole grains
|
Vitamin
B3 (Niacinamide, Nicotinic acid)
|
13 – 19
mg
|
Essential for
energy metabolism and nerve function
|
Lean meat, seafood,
milk, yeast, enriched cereals, whole grains
|
Vitamin
B5 (Pantothenic acid)
|
4 – 7 mg
|
Essential for
energy metabolism and nerve function
|
Legumes, meat,
fish, poultry, wheat germ, whole grains
|
Vitamin
B6 (Pyridoxine acid)
|
2 mg
|
Essential for
carbohydrate and protein metabolism, immune function, red blood cell
production, nerve function.
|
Oatmeal and
cereals, banana, plantain, poultry, liver
|
Folate
(Folic acid, Folacin)
|
400 µg
|
Vital for red blood
cell synthesis, Essential for the proper division of cell, Maternal folate
deficiency may result in an infant with birth defects
|
Fortified cereals,
green leafy vegetables, liver, lentils, black eyed peas, orange juice
|
Vitamin
B12 (Cobalamin)
|
2 µg
|
Required for red
blood cell production, energy metabolism, and nerve function.
|
Ground beef, lever.
Seafood, milk, cheese
|
Biotin
|
30 – 100 µg
|
Participates in
energy metabolism, fatty acid formation and utilization of the B vitamins.
|
Legumes, whole
grains, eggs, organ meats
|
Vitamin C
(Ascorbin acid, Ascorbate)
|
60 mg
|
Antioxidant, role
in growth and repair of tissue, increases resistance to infection and
supports optimal immune function.
|
Cantaloupe, citrus
fruits, strawberries, asparagus, cabbage, tomatoes, broccoli.
|
FatSoluble Vitamins
Vitamins
|
Recommendations
|
Functions
|
Food
Sources
|
Vitamin A
(Retinol, Retinolds, Carotene)
|
800 –
1000 µg RE or 5000 IU
|
Growth and repair
of body tissues, immune function, night vision, carotene is the water soluble
from with antioxidant properties.
|
Oatmeal, green and
yellow fruits and vegetable, liver, milk
|
Vitamin D
|
5 – 10 µg or 200 - 400 µg
|
Regulates calcium
metabolism and bone mineralization.
|
Fortified milk, egg
yolk, salmon and sunlight.
|
Vitamin E
(Alpha, Tocopherol)
|
8 – 10 mg
|
Antioxident,
protects cell, membranes and enhances, immune function
|
Fortified cereals,
nuts, wheat germ, shrimp and green vegetable.
|
Vitamin K
|
60 – 80 µg
|
Assists in blood
clotting and calcium metabolism
|
Green and leafy
vegetable
|
Minerals
Minerals also do not provide energy, although some
are involved in the process of energy production like vitamins.
Minerals can be classified into :
Macro minerals: minerals that required in
relatively large amounts. (Celcium, chloride, magnesium, phosphorus, potassium
and sodium).
Micro minerals : Minerals that also required but in
small amounts that knows as trace elements. (iodine, chromium, copper,
fluoride, iron, manganese, molybdenum, selenium and zinc).
Macro
Minerals
Minerals
|
Functions
|
Food
Sources
|
Calcium
(Ca)
|
Bone formation,
enzyme activation and nerve impulse transmission and muscle contraction.
|
Milk, cheese,
yogurt, dried beans and peas, dark green leafy vegetable, calcium –fortified
products.
|
Fluoride
(F)
|
Helps from bones
and teeth
|
Milk, egg yolk,
drinking water and seafood.
|
Magnesium
(Mg)
|
Protein synthesis,
glucose metabolism, smooth muscle contraction, and bone component.
|
Milk and yogurt,
dried beans, nuts, whole grain products, fruits and green leafy vegetable.
|
Potassium
(K)
|
Ion in
intracellular fluid, glucose transport into cell.
|
Banana, citrus
fruit, fresh vegetable, milk, meat and fish.
|
Sodium
(Na)
|
Ion in extra
cellular fluid, nerve impulse conduction, muscle contraction, acid-base
balance, blood volume homeostasis.
|
Salt, canned and
processed food, soy sauce.
|
Micro
Minerals
Minerals
|
Functions
|
Food
Sources
|
Ferum
(Fe)
|
Hemoglobin and
myoglobin formation, electron transfer, essential in oxidative process.
|
Meat, internal
organ, fish, poultry, whole grain products, green leafy vegetable and dried
fruits.
|
Copper
(Cu)
|
Proper use of iron
and hemoglobin in body.
|
Organ meat, meat,
fish, nuts, eggs, whole grain bread, bran cereal and banana.
|
Zinc (Zn)
|
Cofactor of many
enzymes, involved in energy metabolism, protein synthesis, immune function,
sensation of taste and smell.
|
Organ meat, meat,
fish, poultry, shellfish, dairy products, whole grain products.
|
Chromium
(Cr)
|
Enhances insulin
function
|
Organ meat, oyster,
cheese, whole grain products, asparagus.
|
Selenium
(Se)
|
An antioxidant enzyme
|
Meat, fish,
poultry, organ meats, seafood, whole grain and nuts.
|
Water
Up to 55% to 65% of the adult body is made up of
water, equivalent in volume up to 40 liters.
Function and importance of water:
- Transporting nutrients and oxygen around the body and excrete metabolic waste via kidneys in urine.
- Body temperature regulation through sweating mechanism.
- Medium for chemical reaction during digestion
- To keep joints and eye well lubricated.
Fluids intake and fluids loss
- Fluids intake: Water, food and drinks.
- Fluids loss: Urine, breathe, sweat, faces.
General Recommendation for Athletes
It is no coincidence that the
diet that is currently being promoted for better health and reduced risk for a
long term disease and premature death forms the foundation of the diet for
sporting performance. A good diet will contain a wide variety of foods in other
to ensure that all the nutrients are present in the required amounts. There are
no “good” or “bad’ foods. All foods can fit in to overall diet, but the
frequency with which some foods are consumed and infrequency of other being
consumed will lead to one diet being good while another will be not so good.
General Eating Rules:
- Eat 5 – 6 times a day (3 meals plus 2 – 3 snacks) every 3 hours. Do not allow more than 5 hours between meals.
- Eat within one hour of awakening. Start your day with breakfast.
- Eat a small snack in the afternoon and before bedtime.
- Eat before you become hungry.
- Distribute calories during the day. Eat dinner by 7.30 pm to 8.00 pm and keep supper light.
- Drink 200 ml of water 10 minutes before each meal. Drink 1.5 liter of water or preferably sports drinks for every hour to training.
- Take time and sit down in a calm environment to eat. Enjoy your food.
- Carbohydrate rich foods and drinks should make up at least half of all meals and snacks.
- Follow the food Pyramid Guide. Keep each meal as close to its recommendation.