Carbohydrates are referred to as energy-giving foods. They provide energy in the form of calories that the body needs to be able to work, and to support other functions.

Carbohydrates are needed in large amounts by the body. Indeed, up to 65% of our energy comes from carbohydrates. They are the body’s main source of fuel because they are easily converted into energy. This energy is usually in the form of glucose, which all tissues and cells in our bodies readily use.

For the brain, kidneys, central nervous system and muscles to function properly, they need carbohydrates. These carbohydrates are usually stored in the muscles and the liver, where they are later used for energy.

The main sources of carbohydrates are bread, wheat, potatoes of all kinds, maize, rice, cassava, ‘shiro’, pasta, macaroni, ‘kocho’, banana, sweets, sugar cane, sweet fruits, and honey. Other foods like vegetables, beans, nuts and seeds contain carbohydrates, but in lesser amounts.

About 10–35% of calories should come from protein. Proteins are needed in our diets for growth (especially important for children, teens and pregnant women) and to improve immune functions. They also play an important role in making essential hormones and enzymes, in tissue repair, preserving lean muscle mass, and supplying energy in times when carbohydrates are not available.

Pregnant women need protein to build their bodies and that of the babies and placentas, to make extra blood and for fat storage. Breastfeeding mothers need protein to make breastmilk.

Sources of protein
The main sources of proteins are meats, chicken, eggs, breastmilk, beans, ground nuts, lentils, fish, cheese and milk.

All animal foods contain more protein than plants and are therefore usually better sources of body building foods. However, even though plant proteins are usually not as good for body-building as animal proteins, they can become more effective nutritionally when both are mixed with each other.

Fats and oils are concentrated sources of energy and so are important nutrients for young children who need a lot of energy-rich food. Fats can also make meals more tasty and satisfying. Fat is found in meat, chicken, milk products, butters, creams, avocado, cooking oils and fats, cheese, fish and ground nuts.

Classification of fats
Fats are classified into saturated and unsaturated fats. The classification is important to enable you to advise your community about which fats can be consumed with less risk to people’s health. Saturated fats are not good for a person’s health.

Saturated fats are usually solid at cool temperatures. Eating too much saturated fat is not good for a person’s health, as it can cause heart and blood vessel problems.

Unsaturated fats are usually liquid at room temperature. These types of fats are healthy fats. Examples include fats from fish, oil seeds (sesame and sunflower), maize oil and ground nut oil and breastmilk.

As a general rule, plant sources of fats are better for a person’s health than the animal sources, because animal fats contain more saturated fats.

Minerals are the substances that people need to ensure the health and correct working of their soft tissues, fluids and their skeleton. Examples of minerals include calcium, iron, iodine, fluorine, phosphorus, potassium, zinc, selenium, and sodium.

Functions of some of these important minerals and examples of sources of food for each of these.

Calcium
Function : Gives bones and teeth rigidity and strength
Source : Milk, cheese, dairy products and Foods fortified with calcium, e.g. flour, cereals. eggs, fish cabbage

Iron
Function : Formation of haemoglobin
Source : Meat, meat products and Eggs, bread, green leafy vegetables, pulses, fruits

Iodine
Function : For normal metabolism of cells
Source : Iodised salt, sea vegetables, yogurt, cow's milk, eggs, cheese, fish and plants grown in iodine-rich soil

Zinc
Function : For children to grow and develop normally; for wound healing
Source : Maize, fish, breastmilk, meat, beans

Fluorine
Function : Helps to keep teeth strong
Source : Water

Vitamins are groups of related substances present in small amounts in foodstuffs and are necessary for the body to function normally. Vitamins are also called protective foods. They are grouped together because, as their name implies, they are a vital factor in the diet.

Classifications of vitamins
Vitamins are classified into two groups:

Fat soluble vitamins (vitamins A, D, E and K) are soluble in fats and fat solvents. They are insoluble in water. So these are utilised only if there is enough fat in the body.

Water soluble vitamins (vitamins B and C, and folic acid) are soluble in water and so they cannot be stored in the body.

The best sources of micronutrients in our diets are fruits and vegetables. These two food groups contain essential vitamins and minerals. Animal sources of foods are also both good sources of micronutrients. However, an adequate micronutrient intake can only be achieved through sufficient intake of a balanced diet that includes plenty of fruits and vegetables. Table 2.1 overleaf sets out the functions of some of the important vitamins and examples of sources of food for each of these.

Vitamin A
Function : Night vision, Healing epithelial cells, Normal development of teeth and bones
Source : Breastmilk, tomatoes, cabbage, lettuce, pumpkins, Mangoes, papaya, carrots, Liver, kidney, egg yolk, milk, butter, cheese cream

Vitamin D
Function : Needed for absorption of calcium from small intestines
Source : Calcification of the skeleton, Ultra violet light from the sun, Eggs, butter, fish, Fortified oils, fats and cereals

Vitamin K
Function : For blood clotting
Source : Green leafy vegetables, Fruits, cereals, meat, dairy products

B complex
Function : Metabolism of carbohydrates, proteins and fats
Source : Milk, egg yolk, liver, kidney and heart, Whole grain cereals, meat, whole bread, fish, bananas

Vitamin C
Function : Prevention of scurvy, Aiding wound healing, Assisting absorption of iron
Source : Fresh fruits (oranges, banana, mango, grapefruits, lemons, potatoes) and vegetables (cabbage, carrots, pepper, tomatoes), Breastmilk

Epithelial cells form the thin layer of tissue lining the gut, respiratory and genitourinary systems.
Calcification refers to the hardening of bones by calcium deposits.
Scurvy is a disease caused by vitamin C deficiency which leads to sore skin, bleeding gums and internal bleeding.

Fibre is a mixture of different carbohydrates which are not digested like other nutrients but pass through the gut nearly unchanged. Foods rich in fibre are ‘kocho’; vegetables like cabbage, ‘kosta’, carrots, cassava; fruits like banana and avocado; peas and beans; whole-grain cereals like wheat flour and refined maize or sorghum.

Fibre should be included in the diet for the following reasons:

Fibre makes food bulky or bigger — this can help a person who is overweight to eat less food
Fibre makes the faeces soft and bulky; this can help prevent constipation
Fibre slows the absorption of nutrients, so it helps nutrients to enter the blood stream slowly. This is important for patients with diabetes mellitus.

Credit : Internet

A 50 kg adult contains about 31 litres of water and a one year old, 10 kg child contains nearly 8 litres of water. Almost every part of the body contains large amounts of water.

People can live without solid food for a few weeks, but we cannot live without water for more than a few days. An adult needs about 2–3 litres of water each day. That is why giving drinks are so important when people lose a lot of water, such as when they have diarrhoea.

Water is essential for life. We need water for a number of reasons:

For the body to make cells and fluids such as tears, digestive juices and breastmilk
For the body to make sweat for cooling itself
For essential body processes — most take place in water
For keeping the lining of the mouth, intestine, eyelids and lungs wet and healthy
For the production of urine, which carries waste from the body.

Source : Internet

Vitamin A keeps your heart, lungs, liver and other organs working properly. Also called beta-carotene, it’s important for reproductive, vision and immune system health.

You can get vitamin A from beef liver, salmon, broccoli, carrots, squash, green leafy vegetables, cantaloupe, apricots, mangoes, dairy products and fortified cereals.

There are eight different essential B vitamins — B1 (thiamin), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folate) and B12(cobalamin).

They all help convert carbohydrates, fats and proteins into energy. Several B vitamins are also necessary for cell development, growth and function.

You may need more B vitamins if you’re elderly, have had gastrointestinal surgery, have a gastrointestinal disorder, or if you abuse alcohol. Women who are pregnant, breastfeeding or plan to become pregnant may need more B vitamins, particularly folate, which has been shown to prevent birth defects, according to the American Pregnancy Association. Up to 15 percent of people are deficient in B12. You may also need more B12 if you have pernicious anemia or are a vegan or vegetarian.

You can get vitamin B from meat, poultry, fish, organ meats, eggs, legumes, seeds, nuts, whole grains, and fortified cereals, breads and pastas.

Also known as ascorbic acid, vitamin C boosts the immune system and increases iron absorption from plant-based foods and supplements. Since it’s an antioxidant, vitamin C protects our cells from damaging free radicals. It also aids in wound healing by helping our body produce collagen.

If you smoke, you need 35 more mg of vitamin C per day than non-smokers because it takes more vitamin C for your body to repair the cell damage caused by free radicals in tobacco smoke.

You can get vitamin C from citrus fruits and juices, kiwi fruit, red and green peppers, strawberries, cantaloupe, broccoli, brussels sprouts, tomatoes, tomato juice and baked potatoes (cooking it this way, with the skin on, retains the folate, B6 and vitamin C.)

Vitamin D builds strong bones by helping our body absorb calcium from food and supplements. It also boosts the functioning of the immune system.

People who avoid the sun or use sunscreen — all smart precautions for skin cancer prevention — may need supplements, as well as people with a malabsorption disorder where the body has difficulty absorbing nutrients (such as Crohn’s or celiac disease).

Vitamin D isn’t found naturally in many foods. Known as the “sunshine vitamin,” most of the vitamin D our body gets is absorbed from the sun through our skin. Foods with vitamin D include salmon, tuna, mackerel, beef liver, egg yolks, mushrooms, and fortified dairy and nut milks and cereals.

Vitamin E protects our cells from free radicals, boosts our immune system and helps prevent blood clots.

You can get vitamin E from sunflower, safflower and wheatgerm oils, sunflower seeds, almonds, peanuts, spinach, Swiss chard, avocados and butternut squash.

Vitamin K is necessary for blood clotting and healthy bones. You may need more vitamin K if you have had bariatric surgery to lose weight or have a malabsorption disorder.

You can get vitamin K from spinach, kale, lettuce, broccoli, soybeans, blueberries, figs, meat, cheese, eggs, and vegetable oils.

Roughly 99 percent of calcium in the body is found in bones and teeth, where it is crucial for structural support. The remainder is found in the blood, muscles and intracellular fluids, where it is a critical part of many metabolic, neurological and muscular functions. Postmenopausal women (who have an elevated risk of osteoporosis) and people who don’t consume dairy products (a primary source of calcium) are the mostly likely to require calcium supplements.

You can get calcium from dairy products (such as milk, cheese, and yogurt), fortified non-dairy milks (such as almond, soy and rice milks), fortified orange juice, sardines with bones, tofu (if prepared with calcium), collard green, kale, and broccoli.

Iron is an essential part of building red blood cells, specifically hemoglobin, a protein that bonds with oxygen to oxygen through the blood from the lungs to the cells throughout your body. Vegetarians need to consume almost twice as much iron daily because the iron in plant-based food is less available to the body than the iron found in animal products. Pregnant women and people with iron-deficient anemia may also need supplements.

You can get iron from meat (especially red meat and liver), seafood, lentils, beans, tofu, cashews, and broccoli.

Magnesium plays an important role in the function of more than 300 enzymes that regulate various processes in the body, including muscle and nerve function, heart rhythms and glucose control. Older adults and people with diabetes may need supplements.

You can get magnesium from almonds, spinach, cashews, peanuts, beans, potatoes, brown rice, dairy products, oats, chicken, beef and broccoli.

Zinc is a mineral that plays an important role in immune function and is essential for normal growth and development during pregnancy and childhood. Vegetarians may also need supplements since the zinc found in plant-based foods is less available to the body than that found in meat and fish.

You can get zinc from red meat, poultry, seafood (especially oysters, lobster and clams), dairy products, whole grains, beans and nuts.

Reach out to your pharmacist to get more information on supplements. Some vitamins (such as vitamin E) are dangerous in high doses, and some may interact negatively with other medications or medical treatment.

If you ask most people in the West, roasting, and baking are almost always the same method applied to different foods. Both of these cooking methods use an oven to expose the food to heat, eventually cooking them. For our purposes, they are the same in terms of technique. Roasting is typically performed between 200 to 400 degrees, though most dishes are between 200 to 350 degrees on the heat setting.

People usually say that roasting is a term meant for veggies and fish. Meanwhile, baking is meant to address foods like cakes and bread. Sometimes, baking can also include things like salmon, as long as other veggies accompany it. Roasting is great for meats, bread, desserts, vegetables, and fish. Anything can be done right with a roast.

Broiling is often seen as the “sibling” to roasting. Unlike roasting, where the heat comes from below the food to be cooked, broiling has its heat source above the heat source. It also happens to have a much higher temperature, one that usually starts at 400 degrees. This allows the food to get crispy on the outside while keeping it all juicy on the inside.

Broiling is best done with meats and seafood.

Frying is one of the most popular methods used in fast food, and it only takes a trip to McDonald’s to see why. This cooking method involves cooking food by entering it in a bath of oil, often after breading it. It can be done in a shallow pan or a fryer. It’s similar to sauteeing, though this is more viewed to add crispiness to food rather than to soften it up.

Frying can be done to almost any food with success.

Steaming is a unique cooking method that involves using the heat from boiling water to steam as a cooking method. This typically requires you to have a real steamer pot and is meant to be one of the gentlest, moisture-friendly cooking methods here. It’s a favorite among Asian culinary chefs.

Steaming can be done with vegetables, fish, desserts, tamales, and dumplings.

Boiling is straightforward. It cooks food by submerging the food in boiling water. This can be done via a slow boil, which means that the water has just started to bubble up. Or, it can be done via a full, rolling boil. Either way, the water has to be at least 212 degrees for it to happen. Some pots are specially made for boiling milk or other goods.

Boiling is best for pasta, soups, teas, liquids, and eggs.

Simmering is a moist heat method very similar to boiling, but with one major difference. Here, the water doesn’t quite make it to the point of boiling. Instead, the heat from the water is just below what it should take to make things boil. To simmer water, bring it to a boil, then decrease the temperature. Many consider fondue to be an excellent example of simmering food.

Simmering is ideal for eggs, grains, vegetables, and pasta.

Considered to be a two-step process, braising is a more complicated cooking method than most. Braising food requires you to sear it in a well-oiled pan first, then transfer it to a large pot to cook while partially submerged in liquid. The liquid can be anything from butter to a rich broth, but it still needs to be there. You can use a regular pot, casserole dish, or dutch oven for this.

Braising is typically reserved for meats and vegetables.

Not to be mistaken for the illegal hunting act, poaching is a wet cooking technique that submerges food in hot (but not simmering or boiling) water. This locks in flavor without the use of oil, butter, or heavy frying. For people on a diet, poaching is one of the best ways to conserve flavor without adding calories.

Poaching is commonly done with eggs, delicate grains, and certain veggies.

Blanching is a more advanced cooking method that takes two steps to perform. First, the food in question is boiled for a short time. This is often called “scalding.” After that, the cooking process is halted by dipping the food into a bath of ice water. This stops the loss of flavor without harming the texture.

Most people use blanching for vegetables.

Light up the BBQ, because grilling is where it’s at. This cooking method is all about exposing food to radiant heat, often from an open flame. Grilling involves many different temperature controls, but most people will need to have a good fire pit or griller for this. If you see char lines on your meat or veggies, it probably was grilled. (Note: You don’t need to have a cool apron for this, but it’s positively encouraged.)

Grilling is a suitable cooking method for fruits, meats, seafood, and vegetables.

Sauteing is a French term defined as cooking food on a well-oiled pan, using either butter, oil, or another type of fat to even out browning. Most people find that sauteing is one of the fastest ways to cook food, which is why regularly flipping and turning over food is a must. To do this well, always heat the oil before you add the food.

Sauteing is a smart choice for veggies, poultry, and meat.

If you ever walked into an upscale steakhouse, the chances are that you’ve seen seared steak on the menu. Searing is a unique cooking method that involves heating a surface to a very high temperature (sometimes hotter than 800 degrees) and placing the food on the surface until a crust forms. This gives steaks the meaty “bite” people adore, all while locking in moisture.

Searing is usually made for meats, seafood, and certain types of vegetables.

People who own a Crock-Pot already know what this is. This is the ultimate cooking method for people who want a “set it and forget” type of cooking method. This involves a slow cooker or a pressure cooker to heat food using low temperatures and higher pressures. The result is food that is tender, can cook over a long time, and tastes delicious.

Pressure cooking is good for meats, stews, pasta, dips, and almost everything else.

Stewing and braising are often mistaken for one another simply because the methods are so similar. Both involve sauteing meat or vegetables, then transporting them into a pot where they’re cooked in a liquid of some sort. The difference is in the cuts of food as well as the level of submersion.

With braising, you have larger cuts of meat that are partially submerged in liquid. With stewing, it’s usually smaller cuts of meat that are immersed in the pot. The result of stewing is a delicious, tender meal that comes with its own gravy. Delicious.

Stews are often made with meats and veggies.

Stir-frying is a favorite among Asian chefs, and it involves using a round pan called a wok. To stir fry something means to heat it over a stovetop using oil and spices. While the food is cooking, traditional cooks will make sure that everything is evenly heated by rotating the wok and stirring the food using a pair of chopsticks or a spatula.