I have previously talked about what our bodies are made of, and made the distinction between body fat and lean body mass, and in my last entry I talked about metabolism and how that affects our ability to lose fat.
So, armed with this information it should be possible to put together a list of fundamental principles for the safe, effective loss of body fat.
1) There Must be a Calorie Deficit
The human body lives of fuel which is measured in calories. As mentioned in my entry about metabolism, one pound of fat equates to around 3500 calories. Therefore if you wanted to lose 1lb of fat a week, you would want to drop your weekly calories by around 3500. It's not quite that simple, but nothing else will matter if you don't grasp this concept first.
Your body burns a certain number of calories through the course of a day and this is affected by many things - age, weight (kind of), your activity level etc. You feed your body via the food and drink you consume. Generally speaking, you'll want to match up the calories that your body needs with the the calories that you consume. In order to lose body fat you need to create a 'deficit' which means that you give your body less calories than it needs thus forcing it to metabolise parts of itself (sounds nasty huh!) - hopefully just the fat and not the lean body mass, in order to survive.
We all know what happens when you give your body more than it needs - it stores the excess calories as body fat.
For most people, when they decide they want to lose some fat they take one of three approaches:
1) Just eat a lot less
2) Cut out all the 'crap' from their diet
3) Ignore the diet, and exercise lots instead
Any of these three approaches has the potential to work but all have their pitfals. To really lose fat effectively, we need to be a little scientific about it.
The main trouble with the approaches above is that they all rely on guesswork. If I eat less than I was before, or eat less of the high calorie stuff then I should lose fat. Or, if I do loads of exercise I should burn off enough calories to lose fat. The theory is sound, and it may work for some people if they just happen to guess correctly. But how do you know how many calories less you are eating than before? How do you know how many your body needs? Thus, how do you know what deficit you are creating? I'll go into these things in more detail in another entry. For now, just realise that this guesswork approach is risky at best.
2) Metabolism Must be Kept High
As I explained in my last entry, any calorie deficit maintained for too long will eventually invoke the body's starvation response which will drop the metabolism and thus negate the calorie deficit that you have created. You absolutely MUST keep that metabolism up to avoid this from happening. There are lots of techniques, here is a summary of them:
1) Keep the calorie deficit relatively small, no more than 25%
2) Eat little and often through the day
3) Don't skip meals
4) Do daily exercise, preferably not last thing at night
Lets go over these in a little more detail...
If the calorie deficit is too large, the metabolism will drop very quickly and dramatically. You'll also feel like crap because you're just not eating enough to function properly. By keeping the deficit small, like 20-25% of your daily calorie needs you are far more likely to be able to offset any small drop in metabolism via exercise. Plus, by basing it on a percentage rather than a fixed amount, it can work for anyone regardless of their needs.
In addition to changes in your 'base metablism', it also dips and rises throughout the day in response to the food you eat and the exercise you do. If you skip meals such as breakfast or lunch and go for hours without food, it will drop. By spreading your food out into 4-5 small meals a day you will stop this from happening. There are other advantages to this approach too. The body needs fuel on a regular basis (hence the dip in metabolism when there is no food), so by eating regularly, you will find that you are not hungry as much and you'll experience a lot less hunger pangs and cravings which can be diet destroyers.
Exercise can instantly boost your metabolism, and of course it burns off calories. Some exercise, particularly strength training, can also have an 'afterburn' effect which means that the metabolism stays elevated for some hours after the exercise is performed. So if you do this kind of exercise some hours before you to go bed, you'll be burning more calories than normal as you go about your normal daily routine. Of course some times this can't be avoided. I do karate twice a week and the class is held late in the evening. By the time I get back I just have time for a quick shower and then its time for bed so I dont benefit from the afterburn here. However, this is just a bonus.
3) Your Must Retain Your LBM
LBM = Lean Body Mass, in case you forgot! Your base metabolism is based mainly on your LBM. In another entry I'll show the formula for working this out. Its crucial that you hang onto your LBM and only lose fat. The easiest way to do this is to ensure that you incorporate strength training into your routine. This tells your body that you need your muscles for the work they are doing and encourages your body to look elsewhere (such as your fat deposits) for its energy.
Also, by training hard you may even be able to gain a little muscle and actually increase your base metabolic rate. However, don't rely on this because in general, for muscles to grow they need a calorie surplus and we're putting ourselves into a calorie deficit. Its possible to lose lots of fat and gain a *small* amount of muscle at he same time, but dont expect to lose loads of fat and gain loads of muscle - it just can't happen.
That's the basics of fat loss and we can summarise all of that into three things:
1) Diet
2) Cardio
3) Strength Training
Wednesday, 13 December 2006
Wednesday, 6 December 2006
All About Metabolism
Do you know anyone who seems to be able to eat as much crap as they like and yet is stick thin? Perhaps you know somebody else who only has to look at half a grape and instantly puts on half a stone! The reason for this descrepancy is that these two people have different metabolic rates.
Put simply, your metabolic rate is the rate at which your body burns calories. The higher the rate, the more calories you will burn. Obviously then, higher is better. Some people are naturally blessed with high metabolisms, others cursed with a low one. Some medical conditions such as an under-active thyroid can lower metabolism. However, you are not stuck with what you've got as there are many factors that influence it.
The first and foremost of these is your muscle. Muscle needs energy, fat does not. The more muscle you carry on your body, the more energy (in the form of food and drink) your body needs to sustain it. Your fat on the other hand can survive all by itself!
So, think for a moment what would happen if you were to go on some crash diet in which you lost a large amount of body weight in a short space of time. Take the example of your friend who lost 1 stone in 2 weeks on the Atkins diet that I mentioned in the last entry. We already know that most of that stone is lean body mass because unless he had a very large amount of fat to lose, probably no more than about 4 lbs of it was fat loss. So if that was the case, your friend has lost 10lbs of lean body mass, which in turn means that his metabolic rate has just dropped dramatically.
In real terms, on average, every pound of muscle requires around 50 calories a day to sustain itself. So if you lost 10lbs of muscle, your body would need 500 calories less per day than it did before! This is disastrous! So let's say that your friend is at first happy with his weight loss so he goes back to his eating habits before the diet but now his body doesn't need as many calories and 500 a day extra are being consumed!
1 pound of fat equates to 3500 calories. Eat 3500 calories too many and you gain a pound of fat. Eat 3500 calories less than your body needs (slowly!) and you lose a pound of fat. It's never that precise but you get the idea. So your Atkins buddy goes back to his old ways, and because he's now eating 500 calories a day more than his body needs, the weight starts creeping back on at a rate of around 1 pound a week (Oh, and this will be fat he's putting on, not lean body mass - that takes effort!). What does he do? Goes back to Atkins of course! He goes on another crash diet, loses another stone and reduces his metabolism further. You get the picture... This is called yo-yo dieting and it's a Bad Thing.
To keep the fat off on a permanent basis then, it becomes apparent that you must keep up your metabolism. A large part of your metabolism is based upon your lean body mass so you want to preserve what you have at all costs.
But there's more to say about metabolism. Your metabolism has a base rate that it works at all the time but it can also rise and dip over a period of weeks, days and even over the course of the day.
What makes metabolism drop?
A great way to make your metabolism drop is to reduce the number of calories you consume! The further your drop them, the more your metabolism will drop! How can tha be? How is anyone supposed to diet if reducing their calories just reduces their metabolism as well? This is probably the biggest problem with a 'diet-only' approach. First I'll explain why it happens.
Have you ever heard stories of people who have managed to survive for weeks without food? Humans have a strong survival instict thats built right in to them. The body can detect when it is being deprived of food. Thus, it tries to conserve precious energy by lowering the metabolism so that it doesn't need as much food. This is called the starvation response. There is usually a delay beween the calories dropping and the metabolism dropping. The higher the drop the shorter delay but this is the reason why even a modest diet can seem to plateau after a few weeks.
Another way to make the metabolism drop is to go without food for long periods of time. I don't mean weeks or days, I mean hours. Lets say you eat dinner at 7pm and you're the kind of person who tends to skip breakfast. You'll probably be hungry before lunch so you grab something at 11am the next day. Your body has gone 16 hours without food and that will trigger the starvation response. While your body is sleeping the metabolism will naturally drop anyway but after you wake up in the morning it will need some food to kick start it into action again. This is the reason why you are often less hungry in the morning if you skip breakfast!
So it seems as though all the things that are involved on a diet will actually cause the metabolism to drop which work against what the diet is trying to do! Exactly! This is why you'll often hear 'diets don't work'.
It's not all bad news. There are several ways to raise your metabolism.
First and foremost, any form of exercise will give your metabolism a big boost whilst the exercise is being performed. So, if you reduce your calories slightly, and exercise daily you should be able to offset the metabolism drop caused by the diet by the increase caused by the exercise.
Secondly, eating will raise your metabolism. Thats why its much better to spread your meals out throughout the day and eat 'little and often' than just eat 2 or 3 big meals.
Put simply, your metabolic rate is the rate at which your body burns calories. The higher the rate, the more calories you will burn. Obviously then, higher is better. Some people are naturally blessed with high metabolisms, others cursed with a low one. Some medical conditions such as an under-active thyroid can lower metabolism. However, you are not stuck with what you've got as there are many factors that influence it.
The first and foremost of these is your muscle. Muscle needs energy, fat does not. The more muscle you carry on your body, the more energy (in the form of food and drink) your body needs to sustain it. Your fat on the other hand can survive all by itself!
So, think for a moment what would happen if you were to go on some crash diet in which you lost a large amount of body weight in a short space of time. Take the example of your friend who lost 1 stone in 2 weeks on the Atkins diet that I mentioned in the last entry. We already know that most of that stone is lean body mass because unless he had a very large amount of fat to lose, probably no more than about 4 lbs of it was fat loss. So if that was the case, your friend has lost 10lbs of lean body mass, which in turn means that his metabolic rate has just dropped dramatically.
In real terms, on average, every pound of muscle requires around 50 calories a day to sustain itself. So if you lost 10lbs of muscle, your body would need 500 calories less per day than it did before! This is disastrous! So let's say that your friend is at first happy with his weight loss so he goes back to his eating habits before the diet but now his body doesn't need as many calories and 500 a day extra are being consumed!
1 pound of fat equates to 3500 calories. Eat 3500 calories too many and you gain a pound of fat. Eat 3500 calories less than your body needs (slowly!) and you lose a pound of fat. It's never that precise but you get the idea. So your Atkins buddy goes back to his old ways, and because he's now eating 500 calories a day more than his body needs, the weight starts creeping back on at a rate of around 1 pound a week (Oh, and this will be fat he's putting on, not lean body mass - that takes effort!). What does he do? Goes back to Atkins of course! He goes on another crash diet, loses another stone and reduces his metabolism further. You get the picture... This is called yo-yo dieting and it's a Bad Thing.
To keep the fat off on a permanent basis then, it becomes apparent that you must keep up your metabolism. A large part of your metabolism is based upon your lean body mass so you want to preserve what you have at all costs.
But there's more to say about metabolism. Your metabolism has a base rate that it works at all the time but it can also rise and dip over a period of weeks, days and even over the course of the day.
What makes metabolism drop?
A great way to make your metabolism drop is to reduce the number of calories you consume! The further your drop them, the more your metabolism will drop! How can tha be? How is anyone supposed to diet if reducing their calories just reduces their metabolism as well? This is probably the biggest problem with a 'diet-only' approach. First I'll explain why it happens.
Have you ever heard stories of people who have managed to survive for weeks without food? Humans have a strong survival instict thats built right in to them. The body can detect when it is being deprived of food. Thus, it tries to conserve precious energy by lowering the metabolism so that it doesn't need as much food. This is called the starvation response. There is usually a delay beween the calories dropping and the metabolism dropping. The higher the drop the shorter delay but this is the reason why even a modest diet can seem to plateau after a few weeks.
Another way to make the metabolism drop is to go without food for long periods of time. I don't mean weeks or days, I mean hours. Lets say you eat dinner at 7pm and you're the kind of person who tends to skip breakfast. You'll probably be hungry before lunch so you grab something at 11am the next day. Your body has gone 16 hours without food and that will trigger the starvation response. While your body is sleeping the metabolism will naturally drop anyway but after you wake up in the morning it will need some food to kick start it into action again. This is the reason why you are often less hungry in the morning if you skip breakfast!
So it seems as though all the things that are involved on a diet will actually cause the metabolism to drop which work against what the diet is trying to do! Exactly! This is why you'll often hear 'diets don't work'.
It's not all bad news. There are several ways to raise your metabolism.
First and foremost, any form of exercise will give your metabolism a big boost whilst the exercise is being performed. So, if you reduce your calories slightly, and exercise daily you should be able to offset the metabolism drop caused by the diet by the increase caused by the exercise.
Secondly, eating will raise your metabolism. Thats why its much better to spread your meals out throughout the day and eat 'little and often' than just eat 2 or 3 big meals.
What Are Our Bodies Made Of?
The first mistake that people ususally make when starting some new diet or exercise plan is confusing weight and fat. Most people say they want to lose weight when in fact what they really want is to lose fat.
Its your excess body fat that makes you physically look fat and flabby. Its your excess internal fat around your organs that make you more susceptible to heart disease and all manner of other ailments.
However, our bodies are not just fat! They are made up of bones, muscle, skin, water (lots of water) and many other things. For simplicity, we usually separate out all of these things into two categories:
1) Body Fat
2) Lean Body Mass
The Lean Body Mass is basically everything that is not fat. This is the good stuff. You need strong bones and muscle to enable you to move around and function normally. As we get older, past around the age of 30 or so our bodies naturally start to lose muscle and our bone density reduces. The lack of muscle tissue makes us weaker, and lets not forget that the heart is a muscle so that is affected too! The lowering bone density can make us more susceptible to breaks and diseases such as osteoperosis.
Getting old sucks! The good news is that it is possible to reduce the effects of this muscle loss and lowering of bone density by regular strength training, but let's leave that for another post.
So we know that our bodies are made up of both body fat and lean body mass so what does it mean to lose weight? When a friend comes up to you and says "Wow, I lost a stone in 2 weeks on the Atkins diet!", what does that mean? Well, it probably means something quite different from another friend who says "It's taken me four months to shift this stone!".
It is actually rather easy to lose 'weight' quickly. Firstly, our bodies are primarily made up of water so dehydration will lead to weight loss which can be quite dramatic. For example, have you seen adverts for services that wrap you in cling film and make claims about how much weight you can lose in the process? Sure, you'll lose a few pounds doing that because you've just sweated out a few pints of water! But what they don't tell you is that when you get home and have a couple of glasses of water that weight is right back where it started! Those kinds of treatments may be wonderful for the skin but they will not do anything to help you permanently lose fat.
Going back to your two friends that both lost a stone in different ways... fat cells are stubbon creatures and it takes your body considerable time and effort to 'burn' the fat that is contained within them. If your body is put into a position where it needs energy quickly, it may not have time to get to the fat cells so it will simply metabolise something it can access quickly, such as a chunk of your right bicep! Ok, that is perhaps a silly metaphor but the point is that body fat must be lost slowly. I'm sure you've all heard the guidelines of no more than 1-2 pounds a week unless you have a lot (like 4+ stone) to lose. The reason for this guideline is that your body simply cannot burn huge amounts of fat quickly and if you try to force it to do so, you'll eat into your lean body mass instead.
Why is this such a bad thing? As I mentioned earlier, the heart is a muscle and if you lose muscle you could be losing part of your heart tissue and the smaller your heart is, the weaker is it. That may sound far fetched but it is not. There was once a singer called Karen Carpenter who suffered from Anorexia for many years. She died aged 32 from a heart attack. Her overall bodyweight had reduced so low that her heart had weakened to the point where it could no longer function.
Of course, that's an extreme case but there is a another reason why lean body mass, in particular muscle, should be very important to somebody interested in losing fat: the amount of lean body mass that your body carries is a primary factor in determining how many calories your body needs on a daily basis.
Its your excess body fat that makes you physically look fat and flabby. Its your excess internal fat around your organs that make you more susceptible to heart disease and all manner of other ailments.
However, our bodies are not just fat! They are made up of bones, muscle, skin, water (lots of water) and many other things. For simplicity, we usually separate out all of these things into two categories:
1) Body Fat
2) Lean Body Mass
The Lean Body Mass is basically everything that is not fat. This is the good stuff. You need strong bones and muscle to enable you to move around and function normally. As we get older, past around the age of 30 or so our bodies naturally start to lose muscle and our bone density reduces. The lack of muscle tissue makes us weaker, and lets not forget that the heart is a muscle so that is affected too! The lowering bone density can make us more susceptible to breaks and diseases such as osteoperosis.
Getting old sucks! The good news is that it is possible to reduce the effects of this muscle loss and lowering of bone density by regular strength training, but let's leave that for another post.
So we know that our bodies are made up of both body fat and lean body mass so what does it mean to lose weight? When a friend comes up to you and says "Wow, I lost a stone in 2 weeks on the Atkins diet!", what does that mean? Well, it probably means something quite different from another friend who says "It's taken me four months to shift this stone!".
It is actually rather easy to lose 'weight' quickly. Firstly, our bodies are primarily made up of water so dehydration will lead to weight loss which can be quite dramatic. For example, have you seen adverts for services that wrap you in cling film and make claims about how much weight you can lose in the process? Sure, you'll lose a few pounds doing that because you've just sweated out a few pints of water! But what they don't tell you is that when you get home and have a couple of glasses of water that weight is right back where it started! Those kinds of treatments may be wonderful for the skin but they will not do anything to help you permanently lose fat.
Going back to your two friends that both lost a stone in different ways... fat cells are stubbon creatures and it takes your body considerable time and effort to 'burn' the fat that is contained within them. If your body is put into a position where it needs energy quickly, it may not have time to get to the fat cells so it will simply metabolise something it can access quickly, such as a chunk of your right bicep! Ok, that is perhaps a silly metaphor but the point is that body fat must be lost slowly. I'm sure you've all heard the guidelines of no more than 1-2 pounds a week unless you have a lot (like 4+ stone) to lose. The reason for this guideline is that your body simply cannot burn huge amounts of fat quickly and if you try to force it to do so, you'll eat into your lean body mass instead.
Why is this such a bad thing? As I mentioned earlier, the heart is a muscle and if you lose muscle you could be losing part of your heart tissue and the smaller your heart is, the weaker is it. That may sound far fetched but it is not. There was once a singer called Karen Carpenter who suffered from Anorexia for many years. She died aged 32 from a heart attack. Her overall bodyweight had reduced so low that her heart had weakened to the point where it could no longer function.
Of course, that's an extreme case but there is a another reason why lean body mass, in particular muscle, should be very important to somebody interested in losing fat: the amount of lean body mass that your body carries is a primary factor in determining how many calories your body needs on a daily basis.
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