Post on 31-Dec-2015
Part of the food is converted into our living flesh as building blocks for cellular molecules and structures, as wells as to replace worn out parts.
Most foods are used as metabolic fuels. They are oxidized and transformed into
ATP.
The energy value of foods is measured in units called kilocalories (kcal) or “large calories (C)” the units counted by dieters.
A nutrient is a substance in food that is used by the body to promote normal growth, maintenance, and repair.
The major nutrients:1. Carbohydrates2. Lipids3. Proteins4. Vitamins5. Minerals6. Water (60% of the volume of the food we eat)
With the exception of Lactose and a small amount of glycogen from meat, all other carbohydrates we eat come from plant products.
Fiber – cellulose; plentiful in most vegetables; not digestible by humans; increases the bulk of the stool and aids in defecation
Most are dietary neutral fats – triglycerides
Saturated fats from animal products such as meat and dairy products, and coconut
Unsaturated from seeds, nuts, and plant oils
Cholesterol from egg yolk, meats, and milk products
Highest quality (complete proteins) comes from animal products
Incomplete proteins – legumes, nuts, cereals
Cereal grains and legumes ingested together provide all the essential amino acids (rice and beans)
Organic nutrients of various forms that the body requires in small amounts
No one food contains all the required vitamins
A, C, E appear to have anticancer effects
Most vitamins function as coenzymes (work with an enzyme to perform a particular function)
The body also requires adequate supplies of seven minerals (inorganic substances)
1. Calcium2. Phosphorus3. Potassium4. Sulfur5. Sodium6. Chloride7. MagnesiumThe most mineral rich foods are
vegetables, legumes, milk, and some meats. Fats and sugars have practically no minerals.
• This table lists foods that contain fat-soluble and water-soluble vitamins.
VitaminsFat-soluble
Function Source
A Maintain health of epithelial cells; formation of light absorbing pigment; growth of bones and teeth
D Absorption of calcium and phosphorus in digestive tract
E Formation of DNA, RNA, and red blood cells
K Blood clotting
Liver, broccoli, green and yellow vegetables, tomatoes, butter, egg yolk
Egg yolk, shrimp, yeast, liver, fortified milk; produced in the skin upon exposure to ultraviolet rays in sunlightLeafy vegetables, milk, butterGreen vegetables, tomatoes, produced by intestinal bacteria
VitaminsWater-soluble
Function Source
B1Sugar metabolism; synthesis of neurotransmitters
B2 (riboflavin) Sugar and protein metabolism in cells of eyes, skin, intestines, blood
Niacin Energy-releasing reactions; fat metabolism
B6 Fat metabolism
Ham, eggs, green vegetables, chicken, raisins, seafood, soybeans, milk Green vegetables, meats, yeast, eggs
Yeast, meats, liver, fish, whole-grain cereals, nutsSalmon, yeast, tomatoes, corn, spinach, liver, yogurt, wheat bran, whole-grain cereals and bread
Minerals and vitaminsMinerals and vitamins
VitaminsWater-soluble
Function Source
B12Red blood cell formation; metabolism of amino acids
Pantothenic acid Aerobic respiration; synthesis of hormones
Folic acid Synthesis of DNA and RNA; production of red and white blood cells
Biotin Aerobic respiration; fat metabolism
Liver, milk, cheese, eggs, meats
Milk, liver, yeast, green vegetables, whole-grain cereals and breadsLiver, leafy green vegetables, nuts, orange juiceYeast, liver, egg yolk
C Protein metabolism; wound healing
Citrus fruits, tomatoes, leafy green vegetables, broccoli, potatoes, peppers
Minerals and vitaminsMinerals and vitamins
Group Example Foods By all groups Some groups
Fruits Apples, bananas, dates, oranges, tomatoes
Carbohydrates
Water
Vitamins: A,C, folic Acid
Minerals: iron, potassium
Fiber
Vegetables Broccoli, cabbage, green beans, lettuce, potatoes
Carbohydrates
Water
Vitamins: A, C, E, K, and B vitamins except B12
Minerals: calcium, magnesium, iodine, manganese, phosphorus
Fiber
Group Example Foods By all groups Some groups
Grain Products
(preferably whole grain; otherwise, enriched or fortified)
Breads, rolls, bagels, cereals, dry and cooked pasta, rice, tortillas, pancakes, crackers, popcorn
Carbohydrates
Proteins
Vitamins: Thiamin (B1), niacin
Water
Fiber
Minerals: iron, magnesium, selenium
Milk Products Milk, yogurt, cheese, icecream
Protein
Fat
Vitamins: riboflavin, B12
Minerals: calcium, phophorus
Water
Carbohydrates
Vitamins: A,D
Meats and Meat alternatives
Meat, fish, poultry, eggs, seeds, nuts, nut butters, soybeans, tofu, other legumes (peas & beans
Protein
Vitamins: niacin, B6
Minerals: iron, zinc
Carbohydrates
Fat
Vitamins: B12, thiamin (B1)
Water
Fiber
When energy intake and energy outflow are balanced, body weight remains the same.
When not, weight is either gained or lost. Researchers believe that several factors –
1. rising and falling blood levels of nutrients (glucose & amino acids)2. Hormones (insulin, glucagon, and leptin)3. Body temperature (rising is inhibitory)4. Psychological factors
-- have an affect on eating behavior through feedback signals to the brain.
The amount of energy used by the body is measured in kilocalories.
The basal metabolic rate (BMR) is the amount of heat produced by the body per unit of time when it is under basal conditions – at rest. (energy needed to perform essential life activities)
An average 70-kg (154 lb.) adult has a BMR of about 60 to 72 kcal/hour.
Factors Variation Effect on BMRSurface Area Large surface area in relation to body
volume, as in thin, small individuals
Small surface area in relation to body volume, as in large, heavy individuals
Increased
Decreased
Sex Male
Female
Increased
Decreased
Thyroxine production Increased
Decreased
Increased
Decreased
Age Young, rapid growth
Aging, elderly
Increased
Decreased
Strong emotions (anger or fear) and infections
Increased
BMR for Males = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.76 x age in years)
BMR for Females = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)
Total amount of kilocalories the body must consume to fuel all ongoing activities.