Lose Fat by Eating More


Disclaimer: If all you do is read the title and do what it says, you’ll be in for disappointment. Also, what I write here is not as applicable to people with extreme fat loss goals, e.g. bodybuilders or other physique competitors, at least not towards the end of their preparation. The last vestiges of body fat behave differently to the rest.

For most people, when they feel like they’re getting too soft (or heavy), they’ll instinctively cut food out of their diet. The most common culprits are carbs – especially sugary foods – and fats – often in chocolate or pizza. If you regularly overeat these foods, it’s hard to make the case that you wouldn’t benefit by removing them. But if you don’t tend to binge on “bad” foods, there is a more effective way: eat more.

Energy Balance

It’s common knowledge that how heavy you are basically depends on two things: how much energy you take in, and how much you expend. It’s only not a direct relationship because the calorie densities of different tissues – e.g. fat compared to muscle – are different.

Calorie expenditure is made up of three components:

  1. BMR – basal metabolic rate, the energy required to keep your body warm and alive while lying down
  2. TEF – thermic effect of feeding, the energy required to run the processes that extract nutrients from food
  3. AT – activity thermogenesis*, all the energy you expend in moving around, whether for the sake of exercise or during daily activities

*Incidentally, I don’t like this term, because although most of the energy you expend while being active is lost as heat, some of it goes into mechanical work, like moving your body around and lifting things.

You might have read the term NEAT, which stands for nonexercise activity thermogenesis. This is – probably correctly – praised as the most effective measure for managing obesity. In other words, getting fat people to take the stairs rather than the lift is more effective than trying to get them to go to the gym. “Activity” refers to all the moving you do; “exercise” is activity you do on purpose for the sake of being active.

A common misconception is that by exercising a lot you can increase your BMR. This is not true, although gaining significant amounts of muscle will increase BMR, as well as the energy cost of all activity. Another common myth, which is particularly annoying, is that some people have “fast” metabolisms and can eat anything they want without gaining weight. These people are often quite skinny. If they weighed their food they would discover the reason they are skinny: they don’t eat as much as they think. If anything, the people with the fastest metabolisms are the very heavy – the ones complaining that they have slow metabolisms. BMR scales strongly with body mass, though it is higher in the very muscular than the very fat, because muscle is more expensive to maintain.

As an aside – another implication of this is the myth of the “hardgainer”, i.e. someone who can’t seem to eat enough to gain muscle mass. I’ll address this in a later article because it deserves more attention.

Energy Throughput

Here we come to my main point: it’s better to input and output large amounts of energy than small amounts. It’s easy to get drawn into the trap of thinking along these lines – in order to lose fat quickly, I should eat a small amount and do loads of exercise.

It’s obviously true that it’s necessary to create a caloric deficit to lose fat, but this is easier with a higher intake for two reasons:

  1. Hunger relates more strongly to intake than to balance
  2. You can work out harder if you’ve eaten plenty

If you set up a very low-calorie diet, e.g. 1800 kcal/day for an active 80 kg man, it will be difficult to train very hard. You can output more energy in training – which you should want to do because it’ll let you hang on to more muscle as you lose the fat – if you’ve eaten more.

Most of the time, if someone is on too few calories, increasing their calories without adding any more training will cause them to lose weight faster, as well as feel, look and perform better. This is because the increase in TEF (more food to process) and AT (more energy to work harder) will outweigh the increase in intake. Additionally, referring to point 1, you will be less hungry if you eat more food, even if you actually end up in a bigger deficit than before.

It’s also worth noting that not all deficits are equal. You may have heard of “starvation mode”, a term referring to the state your body gets into when you eat below maintenance for a long time. Essentially, it values amino acid-containing structures like muscle less highly than it values fat, and you end up losing a disproportionate amount of muscle tissue in order to spare fat. This is broadly true, but it is more complicated.

Consider also that if your plan is to have a low caloric intake and a modest expenditure, you have nowhere to go. You can’t eat less because you’re already starving yourself, and you can’t do more because you’re tired and hungry all the time. With a high throughput, you have more room to manoeuvre.

Carbs and Performance

My final point is on macronutrient ratios. There is more to write about this but in essence, people instinctively cut carbs from their diet. This is a crucial mistake, because having low carbs on a deficit – unless you’re a competitive bodybuilder or similar (as mentioned at the top) – will leave you unable to train at a decent level. Willpower is irrelevant when glycogen is low. Having high glycogen stores is beneficial for other reasons, for example retaining (or even building) more muscle while losing fat. Keep your carbs high enough to have energy to train – don’t fear them just because it was trendy to cut them out in the late 20th century.


In short, I suggest turning yourself into a furnace – high input of fuel and high output of heat. This is an approach that has worked well for many of my clients (and for me), and has the added benefit of being more fun than the other way. As I’ve said before, I believe in efficiency – partly because being hungry sucks, and partly because unnecessary suffering makes you more likely to quit.