THE FOUR FOOD GROUPS
Introduction
Sometimes it can be difficult to understand the different food groups. Set out below is a simplified breakdown explaining each of the four food groups which will assist in maintaining a balanced diet.
It is important to eat a wide variety of foods. Eating from the four basic food groups is the easiest way to get everything you need for a healthy diet. It is possible to be a vegetarian or a vegan (no diary products or meats) and still be very healthy, but it requires a lot of careful planning to get all the protein, vitamins, and minerals you need.
The four food groups are:
1. Fruit and Vegetables
2. Grains and cereals
3. Dairy products
4. Meats
THE THREE BASIC NUTRITIONS
All food can be divided into three parts - carbohydrates, fats, and proteins. The first two provide most of the fuel for the body to run on, while the third also provides the raw material for the cells and tissues.
Carbohydrates
Carbohydrates have four calories per gram.
The brain and nervous system run on the glucose provided by carbohydrates.
Carbs fuel the muscles during exercise.
Carbs help maintain tissue protein.
The body converts protein to carbohydrates when carb stores are low.
100 to 150 grams of carbohydrate are needed to prevent drawing on the body's proteins.
Carbs aid in the breakdown of free fatty acids.
Complex carbohydrates - fruit, vegetables, whole grains - are good because they convert to blood sugar more slowly and provide energy longer. They are also excellent sources of vitamins, minerals and fibre.
Refined carbohydrates - sugar, sweets, soft drinks, white bread etc. are bad because they have zero nutrition value, they pack a load of calories and their quick energy jags are rapidly depleted.
Fats
All fats have nine calories per gram.
Fats are the main form in which energy is stored.
They are the energy source for prolonged low-to-moderate intensity exercise.
Fats are the 'shock absorbers' for the vital organs.
Fats provide insulation from hot and cold.
Fats are a source of vitamins A, D, E and K.
Simple fats are triglycerides (95 per cent of body fat), which are divided into saturated fatty acids, and unsaturated fatty acids.
Saturated fatty acids which are solid at room temperature are obtained from animal fats and include meat, egg yolks, dairy products and shellfish.
Unsaturated fats, which are liquid at room temperature come from plant sources, including corn oil, safflower oil, olive oil, and peanut oil.
Compound fats are simple fats combined with other chemicals. The main ones are phospholipids, which are a key component of cell membranes, and lipoproteins, which transport fat in the blood. These are the HDLs (high density lipoproteins), LDLs (low density lipoproteins, and VLDL (very low density proteins). HDLs the good cholesterol lipoproteins, ferry cholesterol away from the walls of the arteries to the liver where it is broken down into bile and excreted through the intestines. The LDLs, the bad lipoproteins, carry the fat throughout the body where they can form deposits in the arteries causing atherosclerosis (narrowing of the arteries).
Derived fats combine simple and compound fats. The best known of the derived fats is cholesterol. Despite its bad reputation, cholesterol is essential for many body functions, including the synthesis of vitamin D, and male and female sex steroid hormones. The liver produces about 500 to 2000 milligrams of cholesterol a day regardless of how much you take in from food. The main dietary sources of cholesterol are egg yolks, organ meats, shellfish, and diary products (not the low or no fat kind).
Proteins.
Proteins have four calories per gram.
Primus inter pares: The first among equals, proteins are the foundation of all life.
Proteins make up one-half of dry body weight, including muscles, skin, bone, hair, teeth, eyes, nails, and scar tissue.
Hormones and enzymes, which orchestrate all the activities of the body, are proteins.
Proteins help maintain water and acid base balance, confer resistance to disease, carry oxygen in the blood, maintain growth and repair of cells and tissue.
Proteins provide 10 to 15 per cent of total energy expenditure during exercise of long duration.
Protein stores are drawn from muscle and liver for energy when there is not enough carbohydrate or protein available from the daily diet, when people diet without exercising or maintaining adequate physical activity, during extended periods of bed rest or immobilisation after injury. This is known as negative nitrogen balance.
Amino acids are the building blocks of protein. There are two kinds of amino acids, essential and nonessential. Essential amino acid cannot be synthesised by the body and must be supplied from the outside. Nonessential amino acids can be made from nonessential amino acids. Complete proteins are composed of essential amino acids. The absence of even one essential amino acid in the right amount will stop protein synthesis.
Protein comes from animal and plant sources. Animal proteins - meat, milk, milk products, fish, poultry and eggs - contain all the essential acids in the correct proportions. Plant proteins - grains and beans - usually lack one or more essential amino acid, but can be combined to form balanced proteins.
-Excess protein is converted to fat and stored in fat cells.
The secret of a healthy diet is to eat a normal diet with small amounts from each food group. Don't eat too much fat and remember that food that is not utilised for energy is stored as fat whether it is protein, carbohydrates or fat. So remember to keep active, exercise three times a week if possible, join a gym, go for brisk walks, swim etc. Be active. USE IT OR LOOSE IT!