The technical definition of a calorie is the amount of heat energy that’s needed to raise one gram of water by one degree Celsius.
And on a more basic level… a calorie is a way of measuring the amount of energy is in the foods we eat.
There are three major kinds of food we eat. They are proteins, carbohydrates and fats. Each of these basic macronutrients contains a specific number of calories per gram of food.
Protein contains 4 calories per gram.
Carbohydrates contains 4 calories per gram.
Fats contain 9 calories per gram.
This same law applies to our body tissues as well, one gram of fat is dissolved to produced to produce 9 calories of energy, so one kilogram of fat equals 9000 calories of energy. If you need to lose 1 kilogram of fat per week, you need to find a way of spending 9000 calories by maintaining a lower level diet and increasing your muscle mass through exercise.
The calorie requirement of every person is unique and the person’s daily requirements depend on few a factors:
1) Basal Metabolic Rate (BMR)
BMR is the amount of calories your body burns in order to sustain its normal daily functions. Your body burns these calories in order to supply energy to your brain for thinking, your lungs for respiration, the heart for continuous pumping, the kidneys for continuous filtering and to support other normal body functions such as digestion, circulation, temperature regulation, cell construction, cell repair and metabolic processes in the body.
BMR is the sum total of all the energy used for basic bodily functions. This does not include daily activity or exercise. Your BMR usually accounts for about 60-70% of your energy expenditure, so if you consume 2000 calories every day, about 1400 calories are taken up to maintain all the metabolic processes in your body.
BMR differs from person to person. A person with high BMR can consume a lot of food almost never gain weight. BMR is an inherited factor and you need to thank your forefathers if you have a fairly good BMR!
BMR varies during different times of the day, BMR is at its lowest when you’re sleeping and not digesting anything.
2) Body size
If you are big in size then your vital organs are going to be larger than the average person and this will increase the number of calories you require to survive everyday.
3) Muscle Mass
The more muscle you have the more calories you burn.
When you have more lean muscle tissue in your body, your body will burn calories even at rest. This increases your BMR. If you want to lose fat and keep it away long term then building lean muscle is one of the best decisions you can make.
BMR reduces with age. As you get older, the amount of muscle you have tends to decrease and fat accounts for more of your weight, which slows down calorie burning. After age 20, your BMR drops about 2% per decade.
5) Body temperature and overall health
For each increase of 0.5C in internal temperature of the body, the BMR increases of about 7 percent. The chemical reactions in the body actually become faster with higher body temperature. During fever, BMR increases.
6) Glandular function
Thyroxin is a hormone which is produced by the thyroid gland. This hormone plays a key role as a BMR regulator, which accelerates the rate of metabolic activity in the body.
In the event that too little thyroxine is produced, BMR can come down 30 to 40% of normal levels. The adrenaline of a person may also increase the BMR.
7) Environmental Temperature
The temperature outside can affect BMR. For example, in extremely cold temperatures, the body must create extra heat to maintain the internal temperature of the body. This raises the BMR. Also, prolonged exposure to a high heat may also increase the BMR.
Men usually have less body fat and more muscle than do women of the same age and weight, burning more calories.
The average male needs around 2400 – 2800 calories per day for normal physical activity while a woman requires only 1800-2200 calories per day to maintain their regular physical activity.
9) Levels of activity
The more active you are the more calories you burn. if you are a couch potato who prefers to be cozy and comfortable like a polar bear, then you’re going to save up all the calories and look like a polar bear soon.
On the other hand if you use every opportunity you get to be active you are going to spend all the calories and lose your fat in the process.
The law of calorie balance
Body fat is a stored form of energy.
If you want to lose the fat you need to spend more energy than you consume.
You need to create a negative calorie deficit so that you lose your fat tissue without compromising muscles.
Once the negative calorie balance sets in, your body is going to break down some form of tissue to meet the energy expenditure needs, so what you are essentially doing here is to put your muscles under some form of workout so they increase in size or at least stay in shape without breaking down and this will direct the body to break down fat instead.
It doesn’t matter how healthy or organic your diet is. If you don’t maintain a negative calorie balance you won’t be able to burn any fat. Healthy and organic diets make a big difference to the quality of your energy and keep you alert throughout the day but they do nothing in terms of fat burning until a negative calorie balance is maintained.
Now we need to adjust this mechanism in such a way that there is a calorie deficit but it does not cause a loss of more than 2 lbs per week.
When you understand the principles mentioned above, you will be able to clearly understand the concept of fat burning.
Let me summarize it as follows:
1) Increasing muscle mass will increase the calories burnt everyday.
2) Keeping the muscles worked out will prevent breakdown of muscle tissue.
3) Maintaining a calorie deficit will signal the body to breakdown some form of tissue, of the muscle tissue stays intact, the fat will begin to break down.
4) Balancing out calorie intake to support weight loss at 1-2 lbs per week will result in healthy and long term fitness.
5) If you don’t maintain a negative calorie balance, you wont see any changes, no matter how healthy your diet.
We will discuss the concepts further in the upcoming chapters.
The right calorie deficit
As mentioned earlier we want to aim and reduce only 1-2 pounds of body weight per week. We do that by maintaining a moderate calorie deficit.
Many books recommend a calorie defecate of 500-1000 calories but that doesn’t work for everybody. The daily calorie requirements depend on all the factors mentioned above. So a 1000 calories may be cutting down on 50% of the diet for a woman on a diet of 2000 calories, (which is too much and sets the body into starvation mode) while a reduction of 1000 calories for man on a 3000 calorie diet may be account for a reduction of 33% in total diet intake.
So what is the right calorie deficit?
The one that works best is a calorie deficit of 15-20%. So if you are taking in 2500 calories per day you want to reduce it by 400-500 calories( 15-20%) per day and if you are on a 2000 calories diet you want to reduce between 300-400 calories.
This type of mild reduction allows the body to adapt gradually and lose weight slowly instead of going in to starvation mode.