This is a (very) basic overview of why you don’t have to drop your calories to ‘famine’ setting to lose weight. Since the female diet and fitness industry is the gift that keeps on giving – a bottomless treasure trove of solid, 24 karat comedy gold – this article is primarily addressed at women. However, the men’s side is fast in pursuit and the overall point here is just as relevant to men.

What even is a calorie?

Normally when we refer to calories we’re actually talking about kilocalories (kcal). One kilocalorie is the amount of energy required to increase the temperature of 1 litre of water by 1oC at sea level. The eagle-eyed amongst you will note that nowhere in this definition is the phrase ‘to be avoided at all costs, you fat shit’. It’s just a unit of energy. It’s not a bad thing. It’s not a good thing. It wasn’t put on this earth to lure humankind down the road to elastic waistbands and mandatory jogging bottoms. Regarding kilocalories as bad is like saying inches are bad, or temperatures are bad. They’re a measurement like any other.

What if I want to lose weight?

Everyone has a ‘maintenance’ energy intake, ie. an amount you need to eat in order to maintain your bodyweight. This amount is highly individual and variable, and occurs where your energy intake is equal to your energy output, which is in turn dictated by your activity levels, metabolic rate, bodyweight and amount of lean (non-fat) mass, among other things. In other words, it’s hard to measure accurately. We aren’t machines; our energy output fluctuates daily, whether we want it to or not.

We all know that in order to lose weight we have to eat fewer calories in a day than we normally do. So we may as well drop straight to the lowest tolerable intake for quickest results, right? Well yes, if you get your diet advice from women’s magazines. Flick through any one at random and you’re all but guaranteed to find a 1300 kcal diet plan that some former soap star swears by, having used it to successfully attain fitness DVD status after ‘ballooning’ to a size 12 (lol). First of all, no one balloons to a size 12 – unless you’re 2 feet high and have become literally as wide as you are tall. Secondly, in approximately 100% of cases said celeb goes off the deep end after her eleventy-billionth meal of chicken and broccoli, puts all the weight back on with a few bonus lbs to boot, and then is invariably papped either in a bikini or emerging from a Starbucks holding what is heavily implied in the accompanying article to be a cup of steaming hot pure lard.

There is a reason for this, and it isn’t a lack of willpower. Your body is an inconsiderate bastard whose sole selfish interest is in keeping you alive. Evolution has not yet found a need for the thigh gap, so until it does, your body will respond to a dramatic slash in calories by slowing down what it can in order to conserve energy. Your body loves to have energy reserves and if you try to take them away, it’ll just start hoarding what it has. Just as you can’t willpower yourself into feeling less cold, or make yourself stay awake for days on end, you can’t willpower yourself not hungry. Two separate levels of brain activity are at war here – your limbic system, which is responsible for the things that keep you and the species going (eg. appetite) and your prefrontal cortex, the seat of decision making and willpower. It isn’t easy to win a fight with your limbic system. It doesn’t care that you go on holiday a week tomorrow, all it knows is that you appear to be trying to survive on salad.

What you need to understand is, we don’t just use energy to move our muscles; everything your body does requires energy – including burning energy (how’s that for some chicken-and-egg shit?). Your organs are demanding: your liver gets through around 350 kcal per day just being a liver – so when your body cottons on to the fact that its calorie availability has suddenly reduced by half, it will assume that times are hard, it’s going to have to run on less, and austerity measures will commence. This is how we as a species survived a history in which we had to arm ourselves to the teeth – or at the very least, put on some trousers – in order to obtain food. Our bodies just haven’t caught up to this brave new 24-hour McDonalds world yet.

So, what’s the answer? Well, you do indeed need to shift your energy balance to ‘negative’ in order to lose weight. You can do it via a reduction in calorie intake, an increase in energy output, or a combination of both. But however you choose to do it, you have to reduce your calorie balance relative to your maintenance calorie intake.

Say twenty women decide to give the 1300 kcal celebrity diet plan a try. The number of daily calories these women will have had to eliminate to get to 1300 will range from a couple of hundred to over a thousand. Why? Because we all have different heights, builds, body compositions, activity levels, lifestyles, health issues and, crucially, genetics. Your genes are the trump card. They dictate everything about you. And if your genes decree (in a heinous abuse of power) that everything you eat goes straight to your arse, well, you’re stuck with it.

Think about that lean person you know who seems to require a trough for their meals, while you’re always on a diet, counting out almonds and occupying yourself with sugar-free jelly until you can get to your next slice of cardboard. Not only do you have a whole different set of physiological parameters to work with, your years of dieting may have caused permanent alterations to your metabolism. Yeah, that happens. If you eat way too little consistently over time, your body will get the message loud and clear. Conserve energy. It can make permanent adaptations to how much energy you burn. Yes, permanent. I’ll write about this in more detail in a later article.

So you can see why losing weight takes an individual and sensible approach, not an arbitrary low-calorie plan cobbled together by some hungover magazine intern.

So how do I know how many calories to eat?

Ok, enough of what not to do. You want answers. Here are answers*:

  • Take a week or so to figure out your maintenance calorie intake. You need to know where you’re starting in order to know where to go. This will make your life much less unpleasant in the coming weeks and months. Log what you eat for a week (use myfitnesspal or some other tracking software for minimal faff) and keep an eye on your weight. Weigh yourself at the same time every day, eg. first thing in the morning, naked and after your morning pee, for a stable point of comparison. If your weight remains stable, there’s your maintenance calorie intake.
  • Shoot for a calorie deficit of around 15%. So if your maintenance calories are 2000, you’ll be aiming for about 1700, which is a nice, manageable 300 calorie per day deficit. Add some extra activity and there’s another couple of hundred, and you don’t have to be hungry. You can eat more on a particularly active day and less on a day where you barely move as long as over the course of the week your average intake is where you want it. And don’t be an idiot – if you take up brutalising yourself in the gym every day, you’re going to have to eat more. You aren’t going to fool your body that way**.
  • Weigh yourself regularly. Not every day; if you’re the sort to dissolve into floods of tears at the sight of a small increase in scale weight, don’t do it. Twice per week is plenty. You are looking for a general downward trend, not a perfect, continuous linear reduction. That won’t happen. Get used to the idea now.
  • As you lose weight, your maintenance calories will of course fall too, because you are less person. This means your dieting calories will have to drop further. This is another reason you don’t drop immediately to rock bottom: there’s nowhere to go from there. You need to start at the highest calorie intake you can that still allows your weight to fall. It may be slow. That’s ok, as long as over time, there’s that downward trend***.

* There are dietary weight loss strategies over and above just calorie management which I don’t cover here. This is about the poor, maligned calorie only.

** On the other side of the coin, ‘walking’ is only exercise if you’re either covering miles of ground or bulldozing around with a weighted vest and some SERIOUS outta-my-way intention. ‘Strolling’ is not exercise – if you want to exercise, put some bloody effort into it.

*** If you are legitimately on a time limit, eg. you compete in a weight class sport, or you have an important look-good event and you’re pretty convinced you’re going to be made to stand on a scale at the door, this may not necessarily apply.

So you can see from the above why:

  1. plummeting your calorie intake to rock bottom is moronic
  2. each of us requires a unique number of daily kilocalories
  3. energy requirement is a massively complex topic with a gazillion influences beyond the scope of this article

Hopefully that sheds a little bit of light on why it’s possible – advisable, even – to drop weight without starvation and/or Ryvita. And why we can’t all use the same identikit plan and expect identical results. So. Put. The women’s magazines. Down.