Fat Loss & Gain – How it Really Works
Body fat, stored energy in adipose tissue, is probably the single most discussed topic related to health, fitness, body confidence and other related areas. Most want less of it, or at least want to spend as much time as possible not gaining it, but I often find that a really big stumbling block people have towards this end is that they’ve never learned the answer to a relatively straightforward question – what IS fat gain and what IS fat loss?
Now I know what you may be thinking – they sound like really stupid questions, to be honest. Obviously the two just mean exactly what they are, right? They are statements that don’t need any further investigation; one is gaining some fat and the other is losing some – but I would put forth the following opinion: if these phrases didn’t need investigation, and so people already know what they mean, then nobody would ever ask:
– Will this make me gain weight?
– Should I cut back on carbs?
– Is (insert food) good for fat loss?
– And many more
A few fitness personalities have started to espouse the idea of ‘it’s just calorie balance’ as the answer to these, and this is of course correct. For example, the answer to the above questions are, in order:
– Not unless it creates a calorie surplus
– Only if it helps you achieve the calorie balance you want
– Only insofar as it helps you create a calorie defecit
Now I’m a fan of this idea, not least of all because it’s true, but it is lacking a couple things which I do think are important. The first thing, which is beyond the idea I’m exploring here, is that the information doesn’t elucidate exactly how the hell the person reading or hearing it is supposed to put that idea into action. Cool, just create a calorie deficit…but what do I eat for breakfast tomorrow?
That’s something that can be explored at a later date, because for now I want to focus on the other thing that this simple phrase lacks: an explanation. You may accept the fact that a calorie deficit or surplus is all that matters for weight management (with body composition and health being a bit more complicated) but unless the reason why that is the case is explained, you’re just expected to take it on faith and that’s a problem.
Some will accept that calorie balance is all that matters, but they’ll get a sneaking suspicion at the back of their mind when they spend a day sitting down and not moving. They’ll still feel bad when eating a big wedge of cake that theoretically fits their calorie needs, and overall they will start to doubt themselves and their behaviour because the framework by which they are supposed to make their decisions is itself not built upon a framework of its own. So here’s the framework:
Humans are living beings, and there are certain rules that govern the existence of such things. For the context today, we will discuss the Law of Conservation of Energy. This law states that energy within a closed system cannot be created or destroyed, it can only be converted into something else. That sounds kinda complicated but what it means is that if you put energy into something it has to go somewhere, and if a system is going to use energy that energy has to come from somewhere. In terms of humans, if you want to walk you need to put some energy in, and conversely if you put energy in it needs to be dealt with. This is how that works inside you.
When you eat, the foods you consume are broken down into their constituent nutrients, namely protein, carbohydrate, fat, and some vitamins/minerals that aren’t important for now. That all ends up in your blood, and your body needs to clear it pretty quickly, so a hormone called insulin is released to facilitate the glucose being stored in glycogen in your muscles and liver, the fatty acids going to your fat cells, and the protein to a few other places that are also not important for today. This means that after eating, you store some energy in your fat stores – this is because the energy that you eat from a typical meal is WAY higher than the energy that is needed right at that moment – think of it like charging a battery.
After a couple of hours, however, when all of that meal has been stored, you’re still moving around and doing things, and that requires energy. As such, a couple of hormones including glucagon are secreted – these release carbohydrate from glycogen and fatty acids from adipose tissue so your body can use these stores to fuel itself. The energy can’t be spontaneously created, so it needs to be taken from the storage facilities.
Over the course of a day, week, month, and year, you are storing and releasing fatty acids from your adipose tissue at almost all times. When you eat a meal the energy is more than is needed and because it can’t be destroyed, it’s stored. In between meals however, the energy necessary to do literally anything can’t be created so it’s released from those same stores. Fat goes in, fat goes out, and it is the net result – dictated by long term energy balance, which ultimately decides if you gain body fat or not. Fat gain is an efficient method of long-term energy storage, which results from chronically consuming more energy than is needed at the time. Fat loss is simply the result of a prolonged period of forcing your body to use its own energy stores to keep going, because you’re not giving it enough energy to do what it wants to do. As such, fat gain and loss is merely energy gain and loss.
And that’s why calorie balance is so important. You can’t cheat this system – if fat is stored, the energy it represents had to come from somewhere, and if you want to lose fat, you can’t spontaneously destroy it; you have to give your body the need to start using it up.
Of course, that’s more difficult than it sounds, but we will return to that another time.