Nutrition is the science that deals with all the various factors of which food is composed and the way in which proper nourishment is brought about to cells and organisms. The intake of food and supplements in the body is utilized for maintaining health, growth and energy or provision of the materials necessary in the form of food to support life. This is made possible with the basic nutrients available in the food. Many common health problems can be prevented or alleviated with a healthy diet.
Aside from not smoking and not drinking alcohol, the most important determinants of good health are what we eat and how active we are? Health nutrition from food we eat and drink is our health and strength. What we eat is part of what we are and what we will become. What we choose for a meal has an impact on our body either positively or negatively. The quality of food we take affects the length and quality of our life. What we choose to eat can have a direct affect on our ability to enjoy life to its fullest. This is true for everyone, despite his or her age and current health. Many life threatening diseases such as heart disease, high blood pressure, diabetes, cancers are often, at least in part, linked to poor nutrition. Much of these diseases could be prevented with sufficient health nutrition intake.
As we know from above that we must eat a balanced diet to obtain healthy nutrition for our wellbeing. However, what is a balanced diet? How to know we are achieving the correct balance? Many of us do not eat enough healthy carbohydrates. Many of us are unaware of a diet which is very low in fat can cause as much harm to our body as a high-fat diet. Many of us do not know that we eat more protein than we really need, and that too much can be bad for us. Many of us fall short on the daily requirement of vitamins and minerals that our body need.
Food is the first thing that comes to our mind with regards to proper nutrition but are we conscious with regards to the importance of proper food and nutrition to our health. No; because some things may influence the food we select that's the reason sometimes many amongst us have ailments and acquire illnesses resulting from poor nutrition that is the reason education is needed regarding proper nutrition.
Humans are complex organisms that need nutrients to sustain the bodily requirements in order to have health and function properly and food is the most essential requirement for human survival as it is a substance that is either eaten or drunk to supply nourishment to the body or for pleasure purposes. The required nutrients such as carbohydrates, fats, proteins, vitamins or minerals found in food that comes from other living organisms such as plants and animals or products, produce energy, replenish old cells, stimulate growth and keep homeostatic life.
There are six main classes of nutrients that the body needs: Carbohydrates (Fiber), Protein, Vitamins, Fats, Minerals and Water. These nutrient classes can be categorized as either macronutrients (needed in relatively large amounts) or micronutrients (needed in smaller quantities). The macronutrients include Carbohydrates, Fiber, Protein, Fats and Water. The micronutrients are Vitamins and Minerals.
The good healthy food mainly consists of Macronutrients, Micronutrients and water. All these are very essential factors for normal functioning of the body. It is important to have these nutrients on a daily basis to build and maintain health. Proper nutrition is only possible when the diet taken is balanced and the food consumed contains all the basic nutrients. The average nutritional requirement will differ for different groups of people and entirely depends on age, sex, height, weight, degree of activity and rate of growth.
A healthy balanced diet is nothing but the nutrients rich food. There are different nutrients essential to generate plenty of energy in the body and immunity against infections and illness. No single food is rich in all the nutrients so variety of food should be included daily to fulfill all the requirements of the body as far as nutrients are concerned. When the food consumed does not fulfill the requirements of nutrients, it leads to malnutrition or under nutrition.
All the nutrients have their own significance and functions in the body. The carbohydrates present in starch, sugar and dietary fibers helps in growth. The fats include different types like unsaturated fatty acids, saturated fatty acids, Trans fatty acids and cholesterol.
Even a single nutrient deficiency can lead to health related problems. Therefore it is very essential to get all the nutrients in required amount. The WHO suggests at least fifty per cent of calories in our diet should come from complex carbohydrates, no more than thirty five per cent comes from fat and up to fifteen per cent comes from protein.
- 50 - 55% Carbohydrates (sugar, sweets, bread, cakes)
- 30 - 35% Fats (dairy products, oil)
- 13 - 15% Protein (eggs, milk, meat, poultry, fish)
Most of the people consume junk and unhealthy food, which doesn't contain the basic nutrients requited by the body. A poor diet can have an injurious impact on our health, causing health-threatening conditions like obesity and metabolic syndrome; and such common chronic systemic diseases as cardiovascular disease, diabetes and osteoporosis.
Nutrient density is defined as a ratio of nutrient content (in grams) to the total energy content (in kilocalories or joules). Nutrient-dense foods have a lot of nutrients, generally with fewer calories. One can compare the nutrient density using the amount of calories in the food.
It has been accepted worldwide that brightly colored fruits and vegetables possess adequate amount of nutrients in them. Whole grain products, like most whole foods, are nutrient dense. Some other nutrient dense foods include dark green vegetables, low-fat meat, fish and low-fat dairy and even fortified foods.
Calories, Nutrients or Food?
Let's understand the difference between calorie intake, nutrient intake and food intake. This is important for the simple fact that the average person doesn't think in terms of calorie intake and they probably don't think in terms of nutrient intake either. Rather, they think in terms of eating food; thus it is very important to examine the distinction between these three 'categories' of intake.
What is a calorie? A calorie (cal) is a measure of heat. One calorie is the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius. Also note that, in all countries except United States, the energy values of foods are measured in Joules, which is just another measure of energy.
To give you an idea of some representative numbers, an average male at about 170 pounds (lbs) has a daily maintenance energy need of about 2700 calories (11,340 Joules). Similarly, an average female at about 135 pounds (lbs) has a daily maintenance energy need of about 2000 calories (8,400 Joules). That number is subject to change and scales with weight (larger individuals having higher daily energy needs and smaller individuals having lower daily energy needs).
- Carbohydrate: 4 calories per gram (16.8 Joules/gram)
- Fat: 9 calories per gram (37.8 Joules/gram)
- Protein: 4 calories per gram (16.8 Joules/gram)
As we know, we don't eat calories but we consume the various macronutrients (Carbohydrates, Fiber, Protein, Fats and Water) which provide calories to the body during their metabolism. As per the chart shown above, the different nutrients provide our body with different caloric values. Example, a gram of protein and a gram of fat will provide 4 and 9 calories/gram respectively.
Also, we don't eat individual nutrients. That is, you don't typically sit down and pick from a tub of protein, a container of fat and a container of carbohydrate. Rather, we probably derive our nutrients (and hence our calories) from food.
Finally, all food contains nutrients in some proportion or another and those nutrients provide energy in the form of calories to the body. From a very simplistic sense, this means that all that matters from a bodily energy standpoint is the caloric content: 2000 calories are always 2000 calories regardless of where they come from.
Healthy Eating Food Guide: Your complete Healthy Nutrition and Food Guide