For anyone who are in the process on gaining or losing weight,they term Calories is likely familiar. But many people don't know what a calorie is or how they work. If you are one of them, this article is for you.
CALORIE DEFINITION:
Scientifically, one calorie is defined as amount of energy required to raise the temperature of 1 gram of water by 1° celsius.
Food we consume is broken down into smaller components like carbohydrates, protein and fats.These nutrients are metabolised to give energy,that is calories. Excess calories are stored as fat.
When we refer to calories in food products , we actually refer to kilocalories(kCal). One kilocalorie equals 1000 calories but for simplicity we use the term 'calories'.
If calorie intake > energy expenditure, you will gain weight
If calorie intake < calories expenditure, you will lose weight.
To maintain balance, we need to know about relation between calories intake and calories expenditure.
Caloric intake :
Total number of calories consumed through food and beverages.
Caloric expenditure:
Total number of calories burned by the body to maintain basic activities and activity throughout the day. Basically calories are burned for three main functions.
TOTAL DAILY ENERGY EXPENDITURE:
• Basal metabolic rate.
•Thermic effect of food.
•Physical activity.
Basal metabolic rate(BMR):
Amount of calories needed to maintain basic physiological function of the body at rest. They may include breathing,circulating blood , regulated body temperature. This accounts for 50-65% of caloric expenditure
Calculating basal metabolic rate:
One of the most appropriate and nearly accurate method to calculate amount of calories needed for basal metabolic rate is the Mifflin-St Jeor equation.
BMR= (10×weight) in kgs + (6.25× height) in cm - (5×age) + parameter.
For this parameter,
Male: 5
Female: -161
Thermic effect of food:
Amount of calories needed to digest the food . Yes, we do require calories today digest the food we consume. This accounts for 10 % of caloric expenditure.
Physical activity:
Calories burned when we perform our daily activities or exercises. These include walking,jogging,running or any physical activity we perform daily. This accounts for 30-50% of caloric expenditure.
CALORIC QUANTITY FOR NUTRIENTS:
Carbohydrates:
1 gram of carbohydrates contain 4 kCal.
Simple carbohydrates:
Sugars like glucose,fructose,sucrose and lactose are simple carbohydrates.These are easily digested and provides rapid energy. It causes spike in blood sugar levels.
Complex carbohydrates:
Starch, fiber found in grains,legumes and vegetables are complex carbohydrates. They are long chains of sugar molecules which take longer time to break down providing sufficient energy.Fiber, a complex carbohydrates does not provide calories.
Functions:
Carbohydrates are important source of brain and muscle's energy resource. They are stored as glycogen in liver and used later.
Proteins:
1 gram of protein contains 4 kCal.
Amino acids:
Proteins are made of amino acids. There are 20 different amino acids which are essential and obtained from diet.
Complete proteins :
These contain amino acids in sufficient amounts. Meat,fish,eggs are examples for complete proteins.
Incomplete proteins:
These lack one or more important amino acids. Plant based diet such as beans,nuts,seeds and grains are examples of incomplete proteins. By combining one or more of these, we can obtain all important amino acids.
Functions:
Proteins are vital for building and repairing body tissue. They produce hormones and enzymes and supports body's immune function.
Fats:
1 gram of fat contain 9 kCal.
Saturated fat:
These are solid at room temperature and consuming it excessively may lead to heart diseases. Meat,butter,cheese contain saturated fats.
Unsaturated fat:
Mono unsaturated fat:
Olive oil,avocados,certain seeds.
Poly unsaturated fat:
Fish, walnuts,vegetable oil, which contain omega-3 and omega-6 fatty acids. They are important for brain function and maintaing cell structure.
Trans fats:
These are created through hydrogenation which solidifies liquid oils. These are found in margarine and baked goods.
Functions:
Fats provide energy during low intese activities. They are crucial for absorbing fat,soluble vitamins, protecting vital organs and insulating the body.
FACTORS AFFECTING CALORIC NEEDS:
Age:
Metabolic rate generally slows down with age that is body burns lesser calories. Older people need few calories than younger individuals.
Gender:
Males generally have high BMR than females due to their high muscle mass.
Body composition:
Muscle burns more calories than fat, even at rest. People with more muscle mass will have higher caloric requirement.
HOW TO MAKE CALORIES WORK FOR YOU:
•Choose foods that are rich in vitamins,minerals and other nutrients but have low calories such as fruits,whole grains.
•Make sure you are acquiring the right balance of carbohydrates,proteins and fats.
•Staying active by performing physical activities, be it running, swimming, cycling help in maintaining muscle mass and a healthy metabolism
Remember it's not just about quantity but also quality, so choose wisely and stay active
