Food
Anything ingested as food gives a creature the nutrition it needs to survive. It often comes from plants or animals and contains vital nutrients such proteins, carbs, lipids, and vitamins. In order to supply energy, support life, or promote growth, the chemical is consumed by an organism and assimilated by the organism’s cells.
Nutrients
The study of nutrition examines how nutrients interact with other components of food (such as phytonutrients, anthocyanins, tannins, etc.) and how these interactions affect an organism’s maintenance, development, reproduction, health, and susceptibility to disease. Food intake, absorption, assimilation, biosynthesis, catabolism, and excretion are all included in this process.
Classification of Food
1. According to their function in the body
I. Energy giving food- carbohydrates and fats.
Protein, lipids, and carbohydrates are all categorized as “calorie nutrients” because they provide the body with the energy it needs to carry out its essential functions. Minerals and vitamins are both regarded as non-calorie nutrients.
II. Body building food-proteins
Body-building foods are things like proteins, lipids, and carbs. They serve as the building blocks for body tissues. 20%, or 1/5 of the total body weight, is made up of proteins. Furthermore 20%, or one-fifth of the body weight, is made up of fat nutrients, whereas just 1% is made up of carbs.
III. Protective foods-vitamins and minerals
The nutrients that control bodily functions are vitamins and minerals. Considering that they are not actually a part of the structural components of the body, minerals make up 4% of the body weight and vitamins about 28 grammes.
2. According to its chemical properties
The nutrients are further categorized into organic and inorganic categories based on their chemical characteristics. The term “organic nutrient” refers to nutrients that contain the element of carbon, while the term “inorganic nutrient” refers to nutrients that do not.
3. According to their essentiality
I. Non-essential Nutrients
Which are produced through precursor molecules, typically important nutrients, but which are not necessary to the organism. Therefore, in order for the body to receive the antecedents of its surroundings, it does not require continuous intake of such a condition. The metabolism of the body generates these.
II. Essential nutrients
Things that the body needs since it cannot synthesize them. Essential fatty acids, essential amino acids, some vitamins, and particular minerals are among them for humans. Water and oxygen are also necessary for human living, but they are not typically regarded as nutrients when taken alone.
4. According to its mass Depending on the quantity necessary for cells and organisms are classified as:
I. Macronutrients
Macronutrients are required in large quantities daily. These nutrients are involved as substrates in metabolic processes for energy. Include proteins, carbohydrates and fats. They are the basis of any diet.
II. Micronutrients
Micronutrients are needed in small quantities (usually in amounts less than milligrams). These nutrients are involved in regulating metabolism and energy processes, but not as substrates. They are vitamins and minerals.
5. According to its origin
Food has been divided into two categories: animal food sources and plant food sources, depending on where it comes from. Foods are compounds derived from both animal and plant sources that, when consumed and absorbed by the body, provide heat and energy. Food nutrients maintain and regenerate tissues and control bodily functions.
6. According to its nutritive value
- 1. Cereals and millets,
- 2. Pulses
- 3. Nuts and oil seeds
- 4. Vegetables
- 5. Green leafy vegetables
- 6. Non-leafy
- 7. Roots and tubers
- 8. Fruits
- 9. Milk and milk products
- 10. Animal foods – meat, fish, liver, egg, etc.
- 11. Carbohydrate foods,
- 12. Condiments and spices
Nutrients their Sources and Function
1. Carbohydrates
Sugar and starches, which are carbohydrates, are the most effective sources of energy and are referred to as the “fuel of life.” They are prevalent in the majority of plant food sources. These are the three-element compounds composed of carbon, hydrogen, and oxygen. Glucose, other sugars, and starch make up the majority of the carbs in diet.
Types of Carbohydrates
Complex carbohydrates (starches) are in breads, cereals, pasta, rice, dry beans and peas, and other vegetables, such as potatoes and corn.
Simple carbohydrates are found in sugars, honey, syrup, jam, and many desserts. Each gram of carbohydrate yields 4 calories in the process of its metabolism.
Sources of carbohydrates
These include cereals such as wheat, maize, rice, potatoes, sugar, honey, bread, sugarcane, and sugar –beet.
Functions of carbohydrates
Carbohydrates serve as the primary energy source for muscular work and nutritional processes, as well as for maintaining body temperature, forming reserves of fuel, assisting in the oxidation of lipids, and freeing up protein for development and repair. The body uses it to produce energy; it also uses it to oxidize fat, promote the growth of beneficial bacteria, produce the vitamin B complex, assimilate minerals, and prevent constipation.
Daily requirements
Children: 60-250 grams, Adolescents: 400 grams, Men: 300 – 700 grams and women: 240 – 540 grams.
2. Fats
Fats’ main purposes are to carry fat-soluble vitamins and to provide energy. There are 9 calories in 1 gramme of fat. Both the animal and vegetable kingdoms have fats. The byproducts of fat breakdown are fatty acids and glycerol. The fat-soluble vitamins A, D, E, and K are transported by many lipids. They also serve as subcutaneous tissue, which helps to retain body heat, and as padding for important organs, including the kidneys. Adipose (fatty) tissue stores fat as a reserve supply for when it’s needed. Obesity, the precursor to arteriosclerosis, hypertension, gallbladder disease, and diabetes, may result from consuming too many calories from fat. A high-fat diet, particularly one heavy in cholesterol and saturated fat, raises blood cholesterol levels in many people. An inadequate amount of fat in the diet can result in underweightness, inadequate protection for the essential organs, and decreased energy. Dietary fats can be found in butter, margarine, cream cheese, fatty meats, whole milk, olives, avocados, egg yolks, almonds, processed baked goods, and vegetable oils.
Fats Sources
Animal sources: ghee, butter, fat of meat, fish oils etc.
Vegetable sources: groundnut oil, ginger oil, mustard oil, cotton seed and nut oil and coconut oil, etc.
Daily Requirements
Man: 20-60 gm
Woman: 20-40 gm
Functions
- Fats provide energy: 1 gram of fat provides 9 calories of energy.
- Dietary fats supplies essential fatty acids needed for growth and maintenance of the integrity of the skin.
- They maintain our body temperature.
- Fats provide support for many organs in our body such as heart, kidneys, intestine etc.
3. Proteins
The “building blocks” of the body, proteins supply vital nutrients that are needed. Proteins are essential for the development, upkeep, and replacement of body cells as well as the repair of damaged tissues. They also create hormones and enzymes that control bodily functions. The daily protein requirement is 1 g/kg body weight. 20% of an adult’s weight is made up of protein, which is composed of amino acids. All biological parts, including muscle, the brain, blood, skin, hair, nails, bones, and bodily fluids, are made of protein.
Sources of Protein
There are 2 main sources of protein.
1. Animal sources: Milk, eggs, meat, fish, cheese etc.
2. Plant sources: Pulses, cereals, beans. nuts, soya bean etc.
Daily Requirements
Infants <6 months: 2 gm/day, Infants 6-12 months: 1.50 gm/day, Child 1-3 yrs: 21 gm/day, Child 4-6yrs: 29 gm/day, Child 7-9 yrs: 40 gm/day, Adolescents 13-15yrs Boys 67 gm/day, Adolescents 13-15yrs girls 62 gm/day, Adolescents 16-18yrs Boys 75 gm/day, Adolescents 16-18yrs girls 60 gm/day, Man: 60 gm/day and Woman: 50 gm/day.
Functions
- Acts as Building blocks of cells and tissues.
- Regulates hemoglobin.
- Regulates muscle contraction, formation of enzyme, hormones and other secretions which help synthesis of enzymes and produces digestive juices and antibodies.
- Act as a source of energy: 1 gm of protein gives 4 kcal.
- Proteins are needed for the growth and repair of the body, they are also called body building food.
4. Vitamins
Vitamins are necessary substances that are only trace amounts in food. Although vitamins don’t provide energy or serve as materials for tissue growth, they do work as catalysts in a variety of bodily chemical reactions and are essential for growth, regular metabolic processes, and overall health of the body.
Although they are just little needed, these are crucial for our development and progress. They produce enzymes that advance the chemical processes in our bodies. They should be routinely consumed because a lack of them can result in illnesses including pellagra, scurvy, and night blindness.
Types
1. Water-soluble vitamins
Water soluble vitamins travel around the body in the bloodstream and are picked up by cells when they are needed. Water-soluble vitamins that are not required by the body are excreted in the urine.
- Vitamin B1 (Thiamine)
- Vitamin B2 (Riboflavin)
- Vitamin B3 (Niacin)
- Vitamin B5 (Pantothenic Acid)
- Vitamin B6 (Pyridoxine)
- Vitamin B7 (Biotin)
- Vitamin B9 (Folic Acid)
- Vitamin B12 (Cobalamin)
- Vitamin C (Ascorbic acid)
2. Fat soluble vitamins
Fat soluble vitamins are stored in body fat (for a few days or as long as 6 months) until the body needs them.
- Vitamin A (Retinol)
- Vitamin D (Calciferol)
- Vitamin E (Tocopherol)
- Vitamin K (Phytonadione)
Sources
- Animal sources: Ghee, butter, fat of meat, fish oils etc.
- Vegetable sources: groundnut oil, ginger oil, mustard oil, cotton seed and nut oil and coconut oil etc.
Daily requirements
- Man: 20-60 gm
- Woman: 20-40 gm Fats
Functions
- Vitamins help in protecting our body against diseases. They also help in keeping our eyes, bones, teeth and gums healthy.
- Fats provide energy: 1 gram of fat provides 9 calories of energy.
- Dietary fats supplies essential fatty acids needed for growth and maintenance of the integrity of the skin.
- They maintain our body temperature.
- Fats provide support for many organs in our body such as heart, kidneys, intestine etc
5. Minerals
Although mineral components make up a very small percentage of the body’s total weight, they are significantly more involved in bodily functions than their weight would suggest.
These are also essential in modest doses for the fundamental growth and structure of our bodies. The 50 or so minerals in our bodies play crucial roles in processes including the development of bones and teeth, the production of blood, the growth of hair and nails, the maintenance of skin integrity, etc.
Minerals
- Calcium
- Chloride
- Fluoride
- Iron
- Magnesium
- Phosphorus
- Potassium
- Sodium
- Zinc
Sources
Egg, meat, milk, cheese, nuts, vegetables, beans, banana, orange, melons, salt etc.
6. Water
It’s common to refer to water as the “forgotten nutrient.” Water is required to replenish body fluids lost, mainly through sweat and urine. Despite not being a food, it is a crucial part of our diets. It is essential for our fundamental metabolism since it facilitates all chemical interactions, regulates body temperature, aids in nutritional processes, and other functions.
Without drinking 8 to 10 glasses of water each day, a diet is not complete. Dehydration brought on by insufficient intake might manifest as weight loss, a rise in body temperature, and lightheadedness.