Hmmm, yes, what about those calories? Where do they come into it?
There is a lot of debate over calorie control and several conclusions have been drawn. I would like to offer my thoughts on calories here.
Firstly, what is a calorie? Well, it is the rate at which a certain thing produces energy. Most people think of calories only in terms of food but this is not so, they apply to anything containing energy. A calorie unit is measured as follows... specifically, a calorie is the amount of energy, or
heat,
it takes to raise the temperature of 1 gram of water 1 degree Celsius
(1.8 degrees Fahrenheit). One calorie is equal to 4.184 joules, a common
unit of energy used in the physical sciences. So, in every day language, calories are the measurement used to determine the amount of energy a thing can provide, strictly speaking, as heat energy.
In scientific terms, energy IN must equal energy OUT. In the world of weight management, the energy IN of course is food/drinks consumed. Our body then very cleverly converts it from the form it was received in, into a form it can use to produce the energy a person needs to function. Many of you will have heard of the Basal Metabolic Rate. This rate varies from person to person according to muscle mass, bone density etc and it is simply the number of calories your body requires to maintain itself in it's current condition if you were to do absolutely nothing except lay still at all times. Of course, most of us do actually move, some more than others! So we need additional calories on top of those required by our BMR to provide us with the energy for these activities. So, if our BMR is 1400 calories per day, and our activity for the day will need and additional 600 calories, we need then to consume a total of 2000 calories for the day to maintain our weight because we will have used up exactly the amount of energy that we put in. If we consumed 2200 calories that day, then technically, 200 calories remain in our bodies! The body has to find a way to store these extra calories, to save them up for the future when they may be needed... and the body's calorie storage mechanism is... you guessed it... FAT!
So, the principle behind that is fairly straight forward, and it therefore stands to reason that, if you want to lose weight, you should reduce your calories to a lower intake than the amount you expend, and you will create a deficit, and your body will delve into it's reserve stores (your body fat) to fuel the extra energy output required. The result, fat/weight loss! Yay! Now here is where we need to be careful though...
A pound of body fat, in a controlled scientific experiment, will produce 3500 calories. It then follows that for every 3500 calories you expend over that which you consume, you will lose 1lb of fat... well, almost.
If you take your time and cut back only a small amount of calories from what you require daily, you should be okay, but you must not cut back by too much. Research has shown that humans can extract approximately 31.4 calories/pound of body fat
daily. After that, the body will have to burn muscle instead. So, let's say you are carrying an extra 10lbs of body fat, your body cannot supplement your energy intake with more than 314 calories from FAT per day. If you eat any less than 314 calories per day below what your body requires, it will use up your muscle instead! Muscle mass really bumps up your BMR so you DO NOT want to reduce it!
In conclusion, I would say that there is little wrong with calorie counting for weight loss and weight management. You just have to be sure to do it in a sensible and thought out way, don't just start eating 1000 calories a day! Do this and I'm sure you will lose weight but then, after a while, your body will adapt, the weight may stop coming off and where do you go from there? You have already gone so low on your calorie intake! You will then have less muscle mass, so your body won't require nearly as many calories as it did before and this will make maintaining any weight loss even harder. Be sensible, get your body fat measured and do the 31.4 calories per pound of body fat calculation. Let's do a quick example of that:
Let's say a person weighs 150lbs. They get their body composition measured. They are carrying 33% body fat which is 50lbs. 50 x 31.4 = 1570 calories. If their BMR was calculated at 1400 and they use 600 on daily activity, and they choose to consume 2000 calories per day, they will maintain their weight. If they cut their calories to 1500 a day, but maintain their 2000 calories expenditure, they will get 500 calories a day to use from their body fat quite safely, and without using up thier muscle because it is well within the 1570 calories that can be withdrawn from their 'fat bank' daily. When they have lost 20lbs, they will only be able to 'withdraw 942 calories from their fat bank' daily, and when they have only 10lbs to lose, they will only be able to withdraw 314 calories daily... meaning they will need to increase the calorie consumption to 1686. By maintaining the muscle, and therefore the BMR, with careful calculation along the way, a person should be able to lose their weight and increase their calorie intake back up to a comfortable 2000 a day to maintain their goal weight once they get there :)
You may need to read this a couple of times to really grasp it, but that is how the calorie equation balances out.