Sunday, March 25, 2012

"Starvation Mode": fact or myth?

Quite a hotly debated subject it seems!

Well... if you've never heard of it before, the theory of starvation mode is that if you do not hit a certain minimum level of calories, your metabolism slows down and your body will start to store more fat.

It's a subject of contention because, well some would say "you cannot put on fat unless you are eating MORE calories than are required to maintain your current weight". And that seems quite logical to me.

HOWEVER there's a bit of a hole in this argument. I'm thinking when people make that argument, it's based on saying "well you're this age, this height, this weight; therefore your maintenance calories is this amount and you cannot gain fat unless you eat more than this". I don't think that's correct.

In most cases you can do the math as described above (also taking account for gender and activity levels) and predict a person's maintenance requirements with reasonable accuracy. Everyone is a little different and interpretations of activity levels can vary but still you can end up with a ball park figure that's pretty close to correct. From there, you just pay attention and tweak things a little as necessary.

Of course... here's the big problem that I think people are forgetting. This equation assumes that we are talking about human beings under normal (medical) circumstances. So, you have the rather odd logic where someone says "if you do this, it'll screw things up and you'll put on fat", and the response is "no, under normal circumstances that is impossible", and the first guy rightly points out "that's why I said 'screw things up', it is no longer normal circumstances". You guys following me on this?

So the theory goes that due to being under-fuelled the body says "ok I need to conserve energy". Metabolism slows and hormonal balance changes. Often the thyroid is affected and stops (or reduces) production of hormones that effect how we burn fat stores. Cortisol production can increase as well, which also encourages the body to hang on to those fat stores.

So at the very least... you could see that the effect might be that the body stubbornly holds on to those fat stores, and perhaps stores more fat at the expense of lean mass. That's assuming we still accept that "you cannot gain weight at below maintenance calories".... so, what we're talking about here is more fat without an increase in weight.

I actually think the human body is far more mysterious than that though. And when you mess with it and make it unhealthy (in this case by under fuelling, perhaps combined with over training), all bets are off. The rules do not apply any more. Results are completely unpredictable. That's why you get people who are quite overweight or obese, despite eating way too few calories to be healthy... or, maybe they're just lying to me about how much they really eat?

Anyway consider this. There was a story not so long ago in the news about a guy who had this massive, like MASSIVE 96kg tumour that needed removed for obvious reasons. Now, I forget where this happened but it wasn't a western country so there were issues with the medical facilities and so forth... so, I'm thinking 3rd world conditions, not an affluent society. So my point is, you're telling me this guy who is otherwise very lean is eating enough to support an extra 96kg of body weight in the form of a tumour?

I mean... I had a tumour once (thyroid) but I was a bit fat and unhealthy at the time and it was maybe a kilo or two (fist sized) not fricken 96 kg. Where the hell does the human body get the resources to grow that thing?

I dunno how it works. I'm not saying that I do. My point is, when we're outside of normal medical circumstances, usual expectations of how things work do not apply. So when you screw with your body with ridiculously low calories, I'm prepared to accept that it's possible to put on weight in the form of increased fat.

Here's the thing though about starvation mode. I'm saying I think it does exist / happen, BUT not in the way that a lot of people talk about it. It's not going to kick in just because you under eat one day for some reason. We're talking about the effects of prolonged under eating, not just skipping a meal or two.

So the bottom line here is; if you're active, training hard and expecting to see a great physique when you look in the mirror, you had better be eating right! Not too much, not too little.

I've been doing some online PT lately and also just giving advice to anyone who asks for it, and rather a lot of people have been coming back to me saying "since I increased my calories like you told me to, I'm seeing much better results already".

More on this subject? Check here: Too Much Exercise, Too Little Food?
Also: Over Training While Under Eating