The basic science behind nutrition
August 28, 2018
Nutrition is the main process by which we intake energy for life. It’s important for our growth, repair and muscle movement. Every living being requires energy and they obtain this energy from the environment, through the process of nutrition.
You might have heard a long definition about nutrition, and ideas of dieticians and doctors and your gym instructor. Unless you have a good scientific background, you will find it difficult to comprehend their pieces of advice. Many in today’s society doesn’t pay much attention to the food they eat, not because they don’t want to, but because they lack a scientific basis on why food is important, and also it is due to the tight schedules we have. This is the reason why many become susceptible to food-related disorders. In order to stay healthy and eat right, here are some scientific points for your knowledge.
The obtainable products of nutrition are the nutrients. Nutrients can be divided into organic and inorganic nutrients. Organic nutrients consist of carbohydrates (carbs), proteins, lipids, and vitamins while the inorganic nutrients consist of water, carbon dioxide, and minerals.
The main process we humans obtain nutrition is through the process of eating or ingestion of liquid or solid food. In order to eat right, it’s important to have at least a sound knowledge of what nutrients are. Nutritional substances (organic nutrients) mainly consists of the following groups.
- Carbohydrates (carbs)
Additionally, drinking adequate volumes of water is also important in order to stay healthy.
So now let’s try to learn a little bit more about these organic nutrients.
Commonly called Carbs or carbohydrates are the first type of organic nutrients, made up of carbon, hydrogen and oxygen atoms. These carbohydrates are available mainly as sugars and polysaccharides (sugar chains). Most commonly used type of polysaccharide in food is starch. Disaccharides and monosaccharides belong to sugars. Sugars are organic compounds that are sweet and soluble.
Starch is available in potato, rice, bread, and cereals. Disaccharides such as sucrose and maltose can be found in sugarcane and malted milkshakes and candies. Finally, monosaccharides like glucose are present in honey and fruits. An adult person needs about 500g of carbohydrates per day. One gram of carbohydrates provide about 4.1-kilocalories when burned in the bomb calorimeter (This is the value of energy of carbohydrates too)
These are the second type of organic nutrients that are found in food. Proteins are made up of monomers called amino acids, and there are commonly 20 amino acids in living organisms. Out of this 20, some can be produced within our body, so we do not need to take them with our food. They are named as non-essential amino acids. The other type cannot be synthesized within our body, so (you guessed it right) they are called essential amino acids. If you find it interesting, here are names of 10 amino acids for your extra knowledge.
Lysine, Phenylalanine, Lucien, Valine, Isoleucine, Arginine, Threonine, Histidine, Methionine, Tryptophan.
Proteins can be found in both plant and animal foods, however, the plant proteins do not have all the essential amino acids, while the animal foods have all of those. Due to this, plant proteins and animal proteins are called as class 2 and class 1 proteins respectively. A grown adult needs about 40 grams of proteins per day. Proteins act as the structural materials of our body.
1) Plant foods that contain proteins: Soy, beans, mushrooms
2) Animal foods with proteins: Meat, milk, eggs, dairy food
Lipids are the third group of organic nutrients that are water-insoluble. 1 gram of fat can produce about 9.3-kilocalories of energy. This value is approximately equal to the double of carbohydrates’ energy value. This is the reason why people can survive on lipid-containing diets like the ketogenic diet. However, lipids take a long time to digest within our stomach. This results in a longer duration of acidic activity within the stomach, leading to gastritis in the long run.
Just like proteins, lipids can also be found in both plants and animal foods. Plant foods that have lipids are vegetable oils. Animal fats are present in Ghee, lard (pig fat) and butter. An adult person needs about 50g of fats per day.
Fibers can be found commonly in plant foods like Broccoli. Plants have cell walls in them, and cell walls are made up of polysaccharides (chains of sugars) called Cellulose, Hemicellulose, and Pectin, as a result, these give rise to plant fibers. Fibers help to make the food into a bulk and support the passage of food through various parts of our body (through a muscular movement called peristalsis) In addition to this, they also retain the moisture in food and facilitate defecation or excretion. Low fiber diets lead to many complications within the intestine, and may even lead to bowel cancer ultimately.
Vitamins are organic compounds that are required in smaller quantities. They can be grouped into two forms of vitamins, as water-soluble vitamins such as vitamin C and B, and lipid soluble vitamins like vitamins A, D, E, and K.
These are a type of salts or ions that are needed for various body functions. They don’t have an energy value. They are divided into macrominerals and trace minerals based on their usage. Macrominerals are required in larger quantities while the trace minerals are required in smaller quantities, but it’s vital to be included in your diet.
Most of our bodies consist of water, and as we metabolize, our body produces toxins. In order to prevent the accumulation of toxins within our body, we need a large volume of water to flush them out. If you want to find out whether you are taking adequate amounts of water, just forget focusing on “this number of glasses per day” and instead, just take a look at the color of your urine. If it is yellowish that means your body needs more water. If you want to stay healthy and fit every day, try incorporating at least four points from the above list to your daily eating routine.