FOOD AND NUTRITION

 

Food and Nutrition
Food and Nutrition
All living organisms require food for their survival. These foods contain a number of food constituents known as Nutrients.
The process by which living organisms take in food and utilize it for their growth and maintenance is called Nutrition.
These complex constituents are broken down by enzymes into simpler forms that can be absorbed by the cells of the body through the process of Digestion.
Food and Nutrition
Absorption: The process of passing digested food molecules across the wall of the intestine into the blood or lymph.
Enzymes: proteins such as pepsin, originating from living cells and capable of producing certain chemical changes in organic substances by catalytic action as in digestion.
Food and Nutrition
Two modes of nutrition among different organisms, Autotrophic Nutrition and Heterotrophic Nutrition.
Autotroph means organisms that prepare their own food from simple raw materials such as water, carbon dioxide and mineral salts with the presence of sunlight, hence they are called Producers.
Food and Nutrition
The organisms which derive their food from other or different organisms are known as Heterotrophic organisms.
They depend for their food on other organisms, hence they are called Consumers.
Food and Nutrition
Difference between heterotrophs and autotrophs is: Heterotrophs cannot synthesize their food while
autotrophs can perform photosynthesis.
Complex organic food prepared by autotrophs or producers are broken down into simple form to derive nourishment (Nutrients).
Food and Nutrition
Foods are complex mixtures of different components, providing varying amounts of the nutrients the body needs.
The nutrients in foods are grouped by their similar characteristics and the functions that they carry out in the body.
Some of these nutrients are Carbohydrates, Protein, Fats, Vitamins and Minerals.
Food and Nutrition
Most foods are a mixture of different nutrients. Certain nutrients are called “Macro” nutrients because the body needs them in fairly large amounts in order to function properly.
These are Carbohydrates, Protein and Fats.
Other nutrients, also necessary for body functions, are called “Micro” nutrients because the body needs them in very small amounts.
These are Vitamins and Minerals.
Carbohydrates
Carbohydrates
Carbohydrates (Carbs) are broken down by the body into glucose for energy and are the basis of a healthy diet.
Generally, they are classified as complex or simple, depending on their structure.
All carbohydrates are made up of chains of sugar molecules. Simple carbs are made up of one or two molecules (monosaccharides or disaccharides). Complex carbs have more molecules in their chains, known as polysaccharides.
Carbohydrates
Complex Carbohydrates include potatoes, yams, cereals and grains such as wheat, oats, rice, legumes, and starchy vegetables.
Starchy vegetables include potato, corn, peas and lentils, while non- starchy varieties include broccoli, tomatoes, cauliflower and mushrooms.
Whole grains are best because they contain all the nutrition including fiber.
Carbohydrates
Simple carbohydrates are basically, sugars.
These sugars take several forms: glucose and fructose found in honey, fruit, and vegetables; lactose (a mixture of glucose and galactose) found in milk; and sucrose is table sugar.
Types of Carbohydrates
Carbohydrates are found in three forms:
Sugar Starch Fiber
Each form of carbohydrate serves different purposes and is important in our diets.
Types of Carbohydrates
Sugar is quickly absorbed into the body and provides calories for energy
It is found naturally in fruits, milk, honey and the sap of certain trees. It is also made from the processing of sugar cane or beets into table sugar or other sweeteners to be added to foods.
Table Sugar
Types of Carbohydrates
Starch is eventually broken down by the body into simple sugars to be absorbed.
Plants that contain starch, or foods made from starchy plants, form the basis of most diets.
Starch is found in grains (rice, corn, wheat, millet, oats), roots and tubers (potatoes, cassava, yams), legumes (peas and beans), and certain fruits (breadfruit, banana, water chestnut).
Carbohydrates in Fruits and Vegetables
Types of Carbohydrates
Fiber is defined as the material in plant foods that the digestive enzymes can not break down into absorbable nutrients.
These substances therefore are not absorbed in the small intestine, and pass intact into the large intestine, where some are broken down by intestinal bacteria, and the rest are excreted.
Types of Carbohydrates
Fiber is needed for efficient digestion, and to keep the heart healthy.
It helps regulate the amount of glucose in our blood
Keeps our energy levels up, and helping concentration and the ability to learn.
It also reduces the chances of developing diabetes and certain cancers.
Types of Carbohydrates
The two types of fiber are insoluble and soluble.
Insoluble fiber (also known as roughage) is found in the husks of whole grains, in seeds and beans, and in the skin of fruit and vegetables.
Soluble fiber is found mainly in fruit, vegetables, beans, and grains such as oats. It absorbs water in the intestines and then works to lower cholesterol in the blood, slows glucose absorption, help prevent heart disease, and to keep our energy levels constant.
Importance of Fiber
Great for weight control (helps one feel full for long, can improve cholesterol and blood sugar levels)
Fight against diseases (diabetes, heart disease and bowel cancer)
5 ways to eat more fiber
Eat more fruit
Eat more vegetables: Eat them raw, steamed, roasted or lightly
boiled. Brassicas such as broccoli are tops for fiber.
Choose high-fiber: whole-grain cereals, preferably with little or no added salt or sugar.
5 ways to eat more fiber
Whole-grain bread: brown, nutty loaves made from wheat, spelt, rye, and/or barley (sometimes with added nuts, seeds, or dried fruit) are the best breads to choose since they are packed with fiber.
Home Bake: Bake your own desserts and pies, such as an apple and blackberry crumble with a whole wheat flour and oat topping, instead of the classic white flour.
5 ways to eat more fiber
Top tips for Carbohydrates
Choose brown over white: Whole-wheat bread and rice gives you the nutrition of the whole grain and plenty of the fiber you need for a healthy digestive system.
Eat whole-grain cereals: Go for oatmeal, granola, or whole-wheat breakfast cereals. Avoid those high in salt and added sugar. Recommended to read the labels.
Eat fruit and vegetables: They are packed with carbs, Leave the skin on, if edible, for maximum fiber.
Avoid tooth decay: All carbs can cause cavities. Worst are refined sugars, dried fruits, and pure juices. Best avoid added sugar, brush and floss twice daily
Proteins
Proteins
Proteins provide amino acids for basic body functions. Amino acids (building blocks) are combined in the body to
create protein substances needed to form body tissues.
They are the main building blocks, as well as the repair kit for the body's tissues such as muscles, bones, organs, blood, skin, and hair.
Proteins
Proteins are perhaps the most essential nutrient for growth because, without protein, the most basic life functions cannot be carried out.
Proteins make up the body’s hormones and enzymes.
They are necessary for clotting blood and for keeping the immune system strong by developing antibodies to fight disease.
Proteins
They repair damaged tissues due to illness or injury.
They are the major component of the body’s transportation system that carries oxygen to maintain proper fluid regulation to remain in their appropriate place in veins, arteries, and cells
Sources of proteins
Protein is found in foods from both animal and plant sources, which provide different combinations of amino acids needed by the body.
All types of meat, poultry, fish, eggs, milk, cheese, and yogurt are foods from animal sources rich in protein. Foods from plant sources high in protein are: dried beans, peas, lentils and other legumes, nuts, pumpkin seeds, and soybeans.
Lipids or Fats
Lipids or Fats
The body needs fat in small amounts.
Fats are made up of carbon, oxygen, and hydrogen. They store vitamins and produce fatty acids. These acids are used to produce cell membranes (thin layers of tissue).
Lipids or Fats
Fat is an energy source that when consumed, serves to transport and increases the absorption of fat-soluble vitamins including vitamins A, D, E, and K;
They are essential for brain function, particularly for helping children to learn and concentrate, and for maximizing the function of an aging brain
They form a large part of all cell membranes and also provide insulation, to help regulate our body temperature and keep us warm.
Lipids or Fats
Fat cell store excess energy and are burned as energy once the body has exhausted all immediate sources in foods.
Sources of fats
Fats can come from animals or plants. They are in meat and dairy products like butter and cheese. Other types of fats are in vegetable oils, nuts or seeds.
There are three main types of fat in food
Saturated Fats Monounsaturated Fats Polyunsaturated Fats
Sources of fats
The saturated form of fat is usually solid at room temperature.
Food sources are animal fats such as butter, milk, cheese, cream, and the fat in meat and poultry. Tropical oils like palm and coconut oils also contain large amounts of saturated fat.
Sources of fats
Monounsaturated fats appear to lower “bad” cholesterol levels in the blood while increasing “good” cholesterol.
Food sources are canola or peanut oil; margarines made from olive, canola, or peanut oil, and nuts seeds.
Olive oil is one of the richest sources of monounsaturated fat.
Sources of fats
Polyunsaturated fats lower total cholesterol levels in the blood, especially when used as a replacement for saturated fats.
These fats are usually found in liquid oils at room temperature such as sunflower, corn, and other vegetable oils.
Other food sources include kinds of margarine made from these oils, nuts, seeds, and fatty fish such as salmon, trout, mackerel, sardines, and tuna.
Good Fats and Bad Fats
Reduce the amount of saturated fat in diets since it can clog the arteries with cholesterol, eat lean meat, do not eat the skin on chicken, and go easy on the cheese.
Eat more polyunsaturated fats such as omegas 3 and 6 and monounsaturated fats, which reduce the level of bad cholesterol in the blood.
Avoid the trans fats (hydrogenated fats) found in some processed foods, since they are like saturated fats, increase bad cholesterol and decrease good cholesterol.
Good Fats and Bad Fats
It is recommended that adults take in low-fat or skim milk, and low-fat yogurt, cream, and cheeses.
Butter is a good source of calcium as well as other minerals and vitamins. It is also the best-tasting fat to use in baking, sauces, and some sautéing. However, it is high in saturated fat, so needed to be used in moderation
Good Fats and Bad Fats
Olive oil spread is a good alternative, or also try making “butters” simply from cooked and puréed dried beans or fresh peas for tasty, wholesome bread spreads.
Omega 3 fatty acids help maintain healthy brains, spinal cord, and eyes, and regulate blood pressure and blood clotting. They may also help prevent heart disease.
Omega 6 fatty acids, found in vegetable oils, are essential for growth, cell structure, and boosting the immune system.
Good Fats and Bad Fats
The fat content of vegetable oils
All oils contain a mixture of monounsaturated, polyunsaturated, and saturated fats.
The fat content of vegetable oils
Cholesterol
Cholesterol occurs naturally in animals.
It is found in all animal products such as meat, poultry, eggs, milk, and cheese.
Plant food sources do not contain cholesterol.
About 80% of cholesterol is made by our liver, while the other 20% comes from our diet.
Cholesterol
The cholesterol that comes from the diet is Low-density Lipoprotein (LDL) Cholesterol.
This is known as the “bad” cholesterol because it contributes to the formation of sticky plaques in our arteries.
High-density lipoprotein (HDL) cholesterol is known as the “good” cholesterol because it can reverse the build-up of plaque in our arteries.
Vitamins
Vitamins
Vitamins are organic compounds produced by living beings.
Their main regulatory duties are to monitor growth, maintain the body's tissue, and help release the energy that is stored in food so the body can use it.
Vitamins
Some vitamins are also involved in the production of blood cells and hormones.
Vitamins help to regulate chemical reactions in the body.
There are 13 vitamins, including vitamins A, B complex, C, D, E, and K.
Vitamins
There are two types, categorized by their solubility
Water-soluble vitamins (B complex, C, and folic acid) dissolve in water, and the excess is expelled as waste.
Fat-soluble vitamins (A, K, E, and D) are stored in our body's fat until needed
Vitamins
VITAMIN A
ROLE: There are two types, retinol, and beta-carotene, vital for growth, healthy skin, teeth, good vision, and a strong immune system, and is a powerful antioxidant against heart disease and cancer.
SOURCES: Retinol from liver, oily fish, egg yolk, and dairy; beta-carotene from red, yellow, orange, and green fruit and vegetables.
Vitamins
VITAMIN B1
ROLE: Also known as thiamin, vitamin B1 is needed for energy production, heart function, and healthy digestive and nervous systems. Also aids general growth and development and helps children concentrate.
SOURCES: Whole grains, legumes (such as peas and fresh soybeans), brown rice, nuts, seeds, and pork.
Vitamins
VITAMIN B2
ROLE: Also known as riboflavin, this vitamin is needed to release energy from food, digest fats and proteins, protect the nervous system, and maintain mucous membranes.
SOURCES: Dairy, fish, meat, eggs, yeast extract, and fortified cereals.
Vitamins
VITAMIN B3
ROLE: Niacin or nicotinic acid; plays a major role in helping convert food into energy, develops and maintains the nervous and digestive systems, and helps in the manufacturing of DNA.
SOURCES: Meat, fish, beans, eggs, nuts, wheat, corn, and fortified breakfast cereals.
Vitamins
VITAMIN B5
ROLE: Pantothenic acid is needed to convert proteins, fats, and carbohydrates into energy and for making vitamin B12, cell membranes, and hemoglobin.
SOURCES: Found in most plant and animal foods. It's particularly high in whole grains, nuts, meat, oily fish, yogurt, snow peas, mushrooms, avocados, cauliflower, Brussels sprouts, and fortified breakfast cereals.
Vitamins
VITAMIN B6
ROLE: Also known as pyridoxine, this vitamin is needed for strong nervous and immune systems, to digest proteins, and to fight infection.
SOURCES: Poultry, organ meats, eggs, oily fish, potatoes, sweet potatoes, bananas, nuts, and whole grains.
Vitamins
VITAMIN B12
ROLE: Needed for growth and development, releasing energy from food, and maintaining a strong nervous system. It's important in the production of energy, and, with folic acid, for healthy blood cells.
SOURCES: Red meat, such as beef and lamb, pork, seafood, eggs, and dairy. The only vegetable source is yeast extract.
Vitamins
FOLIC ACID
ROLE: Another B vitamin, also called folate, helps make healthy red blood cells and reduces the risk of defects in the central nervous system of unborn babies.
SOURCES: Leafy greens, asparagus, broccoli, Brussels sprouts, liver, beans, whole grains, and fortified grains.
Vitamins
VITAMIN C
ROLE: Ascorbic acid, a powerful antioxidant, protects against infection and helps heal wounds. It is easily destroyed by heat and light.
SOURCES: Best in kiwis, berries, pomegranates, citrus fruit, potatoes, winter squash, bell peppers, and cruciferous vegetables.
Vitamins
VITAMIN D
ROLE: It is important for the absorption of calcium and phosphorus, and for building and maintaining healthy bones and teeth. It also boosts the immune system and helps muscle function.
SOURCES: Largely manufactured in our skin when it’s exposed to sunlight, but also in oily fish, eggs, and fortified low-fat spreads and cereals.
Vitamins
VITAMIN E
ROLE: An antioxidant, vitamin E is needed for healthy skin and heart and for a strong immune system. This vitamin is also used in topical creams to reduce scarring.
SOURCES: Vegetable, nut and seed oils, avocados, almonds, dairy, seeds, eggs, soy and whole grains, and fortified low-fat spreads.
Vitamins
VITAMIN K
ROLE: Mainly needed for blood clotting and healthy bones. Babies are given an injection of vitamin K at birth, since their body supply does not kick in immediately.
SOURCES: Most is produced in the digestive system but also in vegetable oils, cereals, green leafy vegetables, particularly broccoli, grapes, and plums.
Minerals
Minerals
Minerals are needed for growth and essential for health
Their main function is to regulate musculoskeletal functions.
They also facilitate blood clotting and help maintain a normal heartbeat.
Minerals are obtained by eating plants that have taken the minerals from the soil and animals that have eaten the plants.
Minerals
There are 16 minerals, divided into two categories, major and trace.
The major minerals are: Sodium, Potassium, Chloride, Calcium, Phosphorus, Magnesium, and Sulphur.
The trace minerals are Iron, Zinc, Selenium, Molybdenum, Iodine, Copper, Magnesium, Fluoride, and Chromium.
Minerals
CALCIUM
ROLE: Calcium is essential for bones and teeth and to help muscles contract, including the heart. Lactose, the sugar found in milk, aids its absorption.
SOURCES: Dairy, smelt, sardines, canned fish, green leafy vegetables, okra, soy products, almond milk, nuts, seeds, tahini, dried figs/apricots, fortified bread.
Minerals
CALCIUM
Osteoporosis is a disease where bones become weak, brittle, and break easily. It is caused by severe losses of calcium.
Minerals
IRON
ROLE: Iron is important for growth and development and crucial in the formation of healthy blood cells, which carry oxygen around the body. Iron from animal products is easier to absorb than that from plants but eating plenty of foods rich in vitamin C helps enormously.
SOURCES: Liver, lean red meat, shellfish, egg yolks, fortified breakfast cereals, dried fruit such as prunes, apricots, nuts, seeds, dark leafy greens and seaweed, beans, oat and wheat bran.
Minerals
IRON
Anaemia: The mineral iron is vital for making red blood cells. Iron from the diet forms haemoglobin, which carries oxygen in the blood. Anaemia, the symptoms of iron deficiency. Large amounts of iron can be toxic.
Minerals
MAGNESIUM
ROLE: Magnesium helps the body process fats and proteins, and build strong healthy bones and teeth. Along with calcium, sodium, and potassium, it also facilitates muscle contraction and the transmission of nerve signals and helps to control the level of calcium in the blood.
SOURCES: Cabbage (best raw), okra, artichokes, sweet potatoes, whole grains, meat, game birds and poultry, dried fruits, especially figs, sunflower and sesame seeds, and nuts, such as cashews, almonds, and peanuts.
Minerals
PHOSPHORUS
ROLE: Vital for healthy bones and teeth, phosphorus also helps store energy needed by body cells. It is essential for the manufacturing of DNA. It is found in all animal and plant proteins, The body needs vitamin D to process phosphorus.
SOURCES: Whole grains, dairy, red meat, poultry, seafood, beans, soy products, nuts, and seeds.
Minerals
SELENIUM
ROLE: Selenium works alongside other antioxidants such as vitamin E and is essential for normal function of the immune system and thyroid gland. It is thought to help protect against cancer, enhance male fertility, and regulate asthma.
SOURCES: Brazil nuts, liver, shellfish, caviar, fish (especially canned tuna), mushrooms, garlic, egg yolk, sesame and sunflower seeds, wheat germ, wheat, oat, and rice bran.
Minerals
POTASSIUM
ROLE: Potassium works in conjunction with sodium and chloride to regulate the amount of water and acid/alkali balance in the body.
It also helps the nerves and muscles to function properly, lowers and controls high blood pressure, keeps the heart healthy, and eases fatigue, irritability, and confusion.
Minerals
POTASSIUM
SOURCES: Many fruit and vegetables but especially bananas, oranges, tomatoes, chard, spinach, mushrooms, fennel (best raw), beets, and potatoes, as well as beans, soy products, bran and bran breakfast cereals, meat, poultry, game, and fish.
Minerals
ZINC
ROLE: Although needed in miniscule amounts, zinc is still essential in normal cell division, growth, and repair, for the immune system and for the development of the reproductive organs and hormones. Zinc also helps regulate moods and appetite, including the sense of taste and smell, and assists in the breakdown of carbs, proteins, and fats.
SOURCES: Fish and shellfish (especially oysters), lean red meat, poultry, whole grains, wheat germ, nuts (especially Brazils), seeds, navy beans, soybeans, eggs, and dairy.
Minerals
SODIUM CHLORIDE
ROLE: Sodium chloride is salt, and is naturally present in most foods. Both elements (sodium and chloride) are crucial in controlling the amount of water in the body and its acid/alkali balance.
Salt also helps muscular contraction. Most people eat too much, which can cause higher blood pressure, heart disease, and strokes.
SOURCES: All foods, particularly high in shellfish.
Water
Water
Although water does not give us energy, it is the most important or essential nutrient.
It is a macronutrient that mainly focuses on regulatory tasks within the body.
Water regulates body temperature, maintains blood volume, and it is the main conduit (canal/outlet) for transporting all forms of nutrients and waste products in the body.
Water
It helps to keep the brain more alert. Children should be encouraged to drink plenty of water. Every cell in our body needs water to function.
The body is made up of around 60 percent water. It controls body temperature and prevents dehydration.
Water also helps to move nutrients around the body, aiding their absorption, and assists in ridding the body of toxins and other waste products.
Drinking plenty of water helps to lessen constipation, urinary tract infections, colon cancer, and kidney stones.
Fruits and Vegetables
Fruits and Vegetables
They are edible plant foods excluding cereal grains, nuts, seeds, tea leaves, coffee beans, cacao beans, herbs, and spices
Fruits and Vegetables
Fruit: Edible parts of plants that contain the seeds and pulpy surrounding tissue; have a sweet or tart taste; generally consumed as breakfast beverages, breakfast and lunch side- dishes, snacks, or desserts
Fruits and Vegetables
Vegetables: Edible plant parts including stems and stalks, roots, tubers, bulbs, leaves, flowers, and fruits; usually includes seaweed and sweet corn;
Generally consumed raw or cooked with a main dish, in a mixed dish, as an appetizer, or in a salad
Fruits and Vegetables
Fruits and vegetables contain many vitamins, minerals, and phytonutrients that are good for your health.
Required to eat at least five servings of vegetables and two serves of fruit each day. Choose different colors and varieties.
A serving of vegetables is about one cup of raw salad vegetables or 1/2 cup of cooked. A serving of fruit is about one medium piece, 2 small pieces of 1 cup canned (no added sugar).
Fruits and Vegetables
Fruit and vegetables for good health:
Reduce obesity and maintain a healthy weight Lower cholesterol
Lower blood pressure
Lower risk of digestive problems
Fruits and Vegetables
Fruit and vegetables and protection against diseases: Type 2 Diabetes
Heart (cardiovascular) disease
prevent some types of cancer
reduce the risk of heart disease
Stroke
High blood pressure (hypertension)
Lower risk of eye disease (cataracts and macular degeneration)
Fruits and Vegetables
Eat non-starchy vegetables and fruits like apples, pears, and green leafy vegetables helps to promote weight loss
Eat a variety of types and colors of produce to give the body the mix of nutrients it needs.
Tips on Fruits and Vegetables
Keep fruit where you can see it Make it a meal
Eat with the seasons
Try something new
Let colors guide you
Fruits
Fruit is the sweet, fleshy, edible part of a plant.
It generally contains seeds.
Fruits are usually eaten raw, although some varieties can be cooked.
Delicious, ready to eat, and abundant in nutrients such as fiber and vitamins.
Comprised of mostly water
Comes in a wide variety of colors, shapes and flavors.
Types of Fruits
The 5 main types of fruits are: Drupes
Berries
Pomes
Hesperidia (Citrus Fruits)
Pepos
Tropical fruits (not always classified as a kind of fruit)
Drupes
A type of fruit that has a single seed in the center surrounded by a hard layer like a shell.
The hard internal part of drupe fruits is surrounded by a juicy, fleshy fruit wall.
Drupes are generally sweet, juicy fruits that are rich sources of vitamins and minerals as well as fiber.
Drupes
Some examples of delicious fruits that are classified as drupes include mangoes, apricots, cherries, nectarines, peaches, plums, and dates.
Among the types of drupes that are “botanically” referred to as fruits are olives, almonds, walnuts, coconuts, and cashews.
Berries
Berries are among the most popular types of fruit because of their varied taste, color, and texture.
Berries are small juicy edible kind of fruits and they can have a sweet, sour, or tart taste.
All varieties of “true” berries do not have a stone in the middle. However, their flesh usually contains seeds as in the case of blackcurrants, grapes, blueberries, gooseberries, and persimmon.
Pomes
Relatively hard flesh that surrounds a core containing seeds.
For example, apples and pears
The characteristic feature of the pome variety of fruits is their central core.
The endocarp, which is the innermost layer that surrounds a seed, can have a leathery or stony texture.
Hesperidia (Citrus Fruits)
These fruits have a thick tangy rind and sectioned pulp inside and come in various colors from green to yellow to orange.
Most citrus fruits such as oranges, lemons, limes, and grapefruit have a soft juicy flesh that is in segments
The protective spongy rind covering the citrus flesh also contains many health benefits.
Hesperidia (Citrus Fruits)
The rind contains volatile oils that are often used to make essential oils.
The outer layer of citrus fruit skins can be scraped to get zest to add to flavor food and beverages.
Pepos
Relatively large fleshy fruits that have multiple seeds throughout the flesh or grouped together in the center
Melons and watermelon are among some of the largest kinds of pepo fruits.
There are certain kinds of pepo “fruits” that are classified as vegetables. These include cucumbers, pumpkin, squash, and, eggplant.
Tropical Fruits
Tropical fruits are not botanically classified as a type of fruits
The list of tropical fruits includes bananas, pineapples, mangoes, papayas, guavas, dragon fruit, rambutan, lychees, and passion fruit
Varieties of plants that produce tropical fruits grow around the equator and include countries in the Caribbean, the northern part of South America, Central Africa, Asia, and islands in the Pacific Ocean
Colors of fruits and vegetables
The most health benefits and protection against disease is eating a wide variety of fruits and vegetables
Foods of similar colors generally contain similar protective compounds. Try to eat a rainbow of colorful fruits and vegetables every day to get the full range of health benefits
Phytochemicals and Nutrients
Red foods: like tomatoes and watermelon. These contain lycopene, which is important for fighting prostate cancer and heart disease
Green vegetables: like spinach and kale. These contain lutein and zeaxanthin, which may help protect against age-related eye disease
Blue and purple foods: like blueberries and eggplant. These contain anthocyanins, which may help protect the body from cancer
White foods: like cauliflower. These contain sulforaphane and may also help protect against some cancers
Phytochemicals and Nutrients
Vegetables
Vegetable usually refers to the fresh edible portions of certain herbaceous plants—roots, stems, leaves, flowers, fruit, or seeds.
Plant parts are either eaten fresh or prepared in a number of ways, usually as a savory, rather than sweet, dish.
Most fresh vegetables are low in calories and have a water content in excess of 70 percent, with only about 3.5 percent protein and less than 1 percent fat.
Vegetables
Vegetables are good sources of minerals, especially calcium and iron, and vitamins, especially A and C.
Nearly all vegetables are rich in dietary fibre and antioxidants.
Classification Vegetables
Vegetables are usually classified on the basis of the part of the plant that is used for food:
Roots and tubers Vegetables Bulb and Stem Vegetables Leafy Vegetables
Podded Vegetables
Fruit Vegetables Flower Vegetables
Roots and Tubers Vegetables
Root Vegetables and tuberous vegetables are part of the staple diet of many people.
Roots and tubers are generally vegetables that have carbs such as starches and sugars
Potatoes, Beets, Carrots, Ginger
Bulb and Stem Vegetables
Types of vegetables where the bulbs and stems are the edible part.
Garlic, Onions, Asparagus, Celery, Leeks, Fennel
Leafy Vegetables
Leafy vegetables are an important source of nutrients.
Many varieties of green leafy vegetables can be eaten raw in salads or boiled as an accompaniment to food.
Some root vegetables such as beets and dandelion produce edible green leaves that are also very nutritious.
Cabbage, Spinach, Brussels sprouts, Lettuce, Kale, Bok choy, Chard, Watercress
Podded Vegetables
Podded Vegetables (or, pod vegetables) include types of vegetables that contain seed, peas, or beans encased in a pod.
Legume is a term for the seeds or fruit of podded vegetables. Beans, Peas, Lentils, Okra
Fruit vegetables
Most popular vegetables are some types of plants that are, botanically classified as fruits, but used in the culinary world as vegetables.
Tomatoes, Cucumbers, Eggplants, Squash, Avocados
Flower Vegetables
Some types of plants produce edible flowers. Broccoli, Cauliflower, Artichoke,
Food Intake
Food Intake
No food has the exact amount of nutrients that are appropriate for everyone.
Some ideas to help figure out how much one need to eat in order to stay at a healthy body weight and maintain energy throughout the day.
Food Intake
You are what you eat
When you look in the mirror your body shape and size will probably tell you whether you’re eating too little or too much (unless your doctor has diagnosed an underlying medical problem). If you are looking very thin and are also constantly tired, it may be that you need to eat a little more.
Alternatively, you may well feel better just by tweaking the balance of the different types of foods, such as eating more starchy carbs for slow release energy, or more fruit and vegetables for extra vitamins and minerals.
Food Intake
Food portion
A portion is the average serving of any food. It is the sensible amount to eat, so children will eat smaller portions, and very active people larger ones.
If you really love a particular food, it is too easy to eat more than enough. So do not keep eating until you feel ready to burst or tired.
Food Intake
Managing your plate
If you know you eat too much, put your food on a smaller plate so that you can not get as much on it.
Also, make sure you dish food out with a tablespoon, not the largest spoon and should also cut down on the fatty and sugary foods.
As a general rule, eat more vegetables, either raw or steamed, without high calorie sauces or dressings. While an extra portion of fruit is also healthful, overdoing it can pose a problem with too much sugar.
Food Intake
Calories per day
Food is used by the body as fuel for energy (measured in calories); each food has a calorific value per gram.
If you consume more than you use in energy, they are stored in the body as fat.
If you consume fewer than you use, your body burns its fat for fuel and you lose weight.
Recommended to ask your doctor what is appropriate for you and your children, If you have any concerns about calories and weight
Nutrient Deficiency and Symptoms
Nutrient deficiencies or diseases can be the result of poor nutritional intake, chronic health conditions, acute health conditions, medications, altered nutrient metabolism, or a combination of these factors, and can impact the levels of both macronutrients and micronutrients in the body.
They can lead to alterations in energy metabolism, immune function, cognitive function, bone formation, muscle function, as well as growth and development.
Balance Diet and Healthy Eating
The foundation for good physical health is good nutritional status. Nutritional status is directly affected by the foods we eat and their nutrient content.
Most nutrients cannot be produced by the body. No single food contains all the nutrients needed by the body in the right amounts. One food may be rich in one or two nutrients, but low in other essential nutrients.
It is only by eating adequate amounts of variety of foods that helps to ensure the right amounts of the nutrients needed for good health and nutritional status.
Balance Diet and Healthy Eating
Balanced diets include a variety of foods from all the food groups to provide the vitamins , minerals, healthy fat, fiber , protein and carbohydrate needed for good health
Making healthy choices from each food group and limiting empty calories from sugary foods or unhealthy fat, can help maintain a healthy body weight.
A balanced diet can reduce the risk of developing certain conditions and diseases, such as obesity, diabetes, certain cancers, hypertension, heart disease, and osteoporosis.
Balance Diet and Healthy Eating
Malnutrition refers to insufficient, excessive or imbalanced consumption of nutrients.
Intake of nutrients below or in excess of needs for long periods of time can affect health.
Malnutrition is an unhealthy state or condition in which a person’s physical functions are temporarily or permanently damaged. Poor, inadequate diets weaken the body, making disease and illness more likely.
Disease in turn often increases the body’s need for food. Repeated and prolonged illnesses, such as diarrhea and malaria, contribute to malnutrition, as nutritional needs are higher during and following illness.
Balance Diet and Healthy Eating
Under nutrition: Kwashiorkor and Marasmus are two common diseases caused by a lack of protein and energy. Kwashiorkor is a disease that occurs, if the body does not get enough proteins. Marasmus occurs in young children who do not get enough calories every day. They become weak, underweight and often die.
Over nutrition: Too much fat and cholesterol in the body can lead to heart diseases, obesity and cancer. High cholesterol levels may make the arteries narrow. This may result in high blood pressure, heart attack or stroke.
Food Poisoning
Food poisoning is caused by the consumption of foods or drinks contaminated with pathogens (including bacteria, viruses and parasites), bacterial or biochemical toxins or toxic chemicals.
Affected persons usually show gastrointestinal symptoms like nausea, abdominal pain, diarrhea and vomiting, although other symptoms like fever may also develop.
The incubation period varies from hours to days depending on the causative agent.
Food which can cause food poisoning may appear harmless, their colour, taste and appearance are normal and there is no evidence of spoilage.
Food Poisoning
Food spoilage can be defined as any decay or undesirable decomposition of constituents by excessive growth of micro- organisms or by other natural causes (physical or chemical changes).
If food spoilage occurs, the food is unpalatable because the colour, taste and appearance have been changed.
Food Poisoning
Food poisoning more properly referred to as a food-borne illness. It is the result of ingestion of food (or water) contaminated with pathogenic microbes, toxic chemicals or toxins produced by microbes.
Most cases of food poisoning are actually intoxications caused by bacterial toxins, either ingested pre-formed or produced by the micro-organisms in the gastrointestinal (GI) tract.
Most of the common food-borne illnesses present with abdominal cramps, nausea, vomiting and diarrhea and have a relatively acute onset.
How do we get food poisoning?
Exposure to possible causes of food poisoning is virtually unavoidable in our society. Much of our food is handled, transported and prepared by dozens of (potentially unwashed) hands before it reaches our mouths.
Any type of food can be a source of gastrointestinal infection.
Mechanisms of food poisoning
Most cases of food poisoning result in diarrhea that is either Secretory or Inflammatory, resulting either damage to the intestinal mucosa causing inflammation (via cytotoxins) or alteration of the balance between absorption and secretion, causing loss of salt and water from the gut (via enterotoxins).
Occasionally, pathogens may act by invading the GI mucosa and causing systemic infection or symptoms related to the production of neurotoxins.
Mechanisms of food poisoning
Secretory Diarrhea: This type of diarrhea is classically caused by pathogens, which elaborate enterotoxins, usually involving the small bowel.
The toxins can act very quickly and cause a relative imbalance between fluid absorption and secretion in the intestinal lumen. The result is acute onset of watery diarrhea, potentially within an hour of eating.
Mechanisms of food poisoning
Inflammatory diarrhea: Inflammatory diarrhea is the result of damage to the intestinal wall caused by pathogens or by cytotoxins released by certain organisms. Damage or destruction of cells lining the gut results in bleeding and inflammation.
As a consequence, the patient experiences bloody diarrhea that will demonstrate an elevated leukocyte count, if tested. The large bowel is more commonly involved. The onset of symptoms is generally delayed compared to the acute onset of secretory diarrhea.
Digestive System
Key Terms
Ingestion: Intake of food into the body through mouth
Mastication: is the process by which food taken into the mouth is chewed
by the teeth.
Absorption: The process of passing digested food molecules across the wall of the intestine into the blood or lymph.
Assimilation: The movement of digested food molecules into the cells of the body where they are used, becoming part of the cells.
Egestion: Passing out of undigested food, in the form of faeces through the anus.
Key Terms
Digestion: The process of break-down of large, insoluble food molecules into small, water soluble molecules using mechanical and chemical processes.
Mechanical digestion: muscular movement of the digestive tract (mainly in the oral cavity and stomach) physically break down food into smaller particles for chemical digestion by enzymes. Mechanical processes include chewing, mixing of food with saliva by the tongue
Chemical digestion: hydrolysis reactions aided by enzymes (mainly in the stomach and small intestine) chemically break down food particles into nutrient molecules , small enough to be absorbed
Digestive System
The human digestive system consists of the alimentary canal and the associated glands.
The alimentary canal begins with an anterior opening – the mouth, and it opens out posteriorly through the anus.
The mouth leads to the buccal cavity or oral cavity. The oral cavity has a number of teeth and a muscular tongue. Each tooth is embedded in a socket of jaw bone
Digestive System
The digestive glands associated with the alimentary canal include the salivary glands, the liver and the pancreas.
Liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human.
Saliva is mainly produced by three pairs of salivary glands, the parotids (cheek), the sub-maxillary/sub-mandibular (lower jaw) and the sublingual (below the tongue).
Digestive System
These glands situated just outside the buccal cavity secrete salivary juice into the buccal cavity.
Functions of Saliva:
Cleanses the mouth;
Dissolves food chemicals so that they can be tasted;
Moistens food and aids in compacting it into a bolus, and;
Contains enzymes that begin the chemical breakdown of starchy foods.
DIGESTION OF FOOD
The process of digestion is accomplished by mechanical and chemical processes.
The buccal cavity performs two major functions, mastication of food and facilitation of swallowing.
The teeth and the tongue with the help of saliva masticate and mix up the food thoroughly.
Mucus in saliva helps in lubricating and adhering the masticated food particles into a bolus.
DIGESTION OF FOOD
The bolus is then conveyed into the pharynx and then into the esophagus by swallowing or Deglutition.
The bolus further passes down through the esophagus by successive waves of muscular contractions called Peristalsis.
The stomach stores the food for 4-5 hours. The food mixes thoroughly the acidic gastric juice of the stomach by the churning movements of its muscular wall and is called the Chyme.
DIGESTION OF FOOD
The small intestine, a principal organ for the absorption of nutrients.
The digestion is completed here and the final products of digestion such as glucose, fructose, fatty acids, glycerol and amino acids are absorbed through the mucosa into the bloodstream and lymph.
The undigested and unabsorbed substances are passed on to the large intestine.
DIGESTION OF FOOD
No significant digestive activity occurs in the large intestine. The functions of the large intestine are:
Absorption of some water, minerals, and certain drugs;
Secretion of mucus which helps in adhering the waste (undigested) particles together and lubricating it for an easy passage.
DIGESTION OF FOOD
The undigested, unabsorbed substances called feces enter into the caecum of the large intestine through the ileocecal valve, which prevents the backflow of the fecal matter.
It is temporarily stored in the rectum till Defecation.
DISORDERS OF THE DIGESTIVE SYSTEM
The inflammation of the intestinal tract is the most common ailment due to bacterial or viral infections.
The infections are also caused by the parasites of the intestine like tapeworms, roundworms, threadworms, hookworms, and pinworms, among others.
DISORDERS OF THE DIGESTIVE SYSTEM
Jaundice: The liver is affected, and skin and eyes turn yellow due to the deposit of bile pigments.
Vomiting: It is the ejection of stomach contents through the mouth. This reflex action is controlled by the vomit center in the medulla. A feeling of nausea precedes vomiting.
Constipation: In constipation, the feces are retained within the rectum as the bowel movements occur irregularly.
DISORDERS OF THE DIGESTIVE SYSTEM
Diarrhea: The abnormal frequency of bowel movement and increased liquidity of the fecal discharge is known as diarrhea. It reduces the absorption of food.
Indigestion: food is not properly digested leading to a feeling of fullness. The causes of indigestion are inadequate enzyme secretion, anxiety, food poisoning, overeating, and spicy food.