Is a Calorie a Calorie? Why “IIFYM” is Misleading

IIFYM is an acronym for ‘If It Fits in Your Macros’ and has become something of a rallying cry for many bodybuilders.

The general idea behind IIFYM is that you can eat whatever you like, as long as it fits within your allocation of carbs and protein.

To better understand how all this started, you need to learn a bit of the backstory…

Where IIFYM Came From

The idea behind ‘macros’ is that you should be eating a certain amount of protein, a certain amount of fat, a certain amount of carbs etc. You can then set yourself a ‘budget’ for each one to reach a certain amount of calories while retaining healthy ratios. If you’re looking to bulk up and add a lot of muscle, you’ll be aiming for a high total calorie count while at the same time leaning more towards increasing protein other sources of calories.

This was the prevailing advice on but a lot of people seemed to overcomplicate the matter and would ask the more experienced users on that forum whether it was ‘okay for them to eat donuts’ while bulking, or ‘okay for them to eat chocolate’ while cutting. The experts on that site soon got tired of people missing the point and so began answering with one simple phrase: “if it fits in your macros”. The point here was that as long as you weren’t exceeding or falling short of your target calories in any given area, you could accomplish your goals.

The Problem With IIFYM

Unfortunately, though some people got a bit carried away with this idea and IIFYM became a ‘fad diet’. People became obsessed with a diet that allowed you to ‘get thin on donuts’ – which was kind of exactly the opposite of what those forum members were aiming for. IIFYM was originally a retaliation against fad diets.

As you might imagine, getting slim on donuts alone is not a particularly healthy approach and neither is bulking up on a diet of KFC. The point is: a calorie is not always a calorie.

Apart from the fact that the calories listed on packets are generally incorrect, it’s also true that not all the calories we consume make it to the blood. Protein has a ‘thermogenic effect’ for instance meaning that you burn a certain number calories from digesting it alone. The speed with which calories hit your blood stream also have an impact which is where ideas like carb backloading come from. Then there’s simple fact that counting calories is boring and soul destroying…

More importantly though, following a strict IIFYM diet allows you to get all your calories from food sources that are effectively empty calories. In order words, by eating just donuts and KFC, you are missing out on all sorts of essential micronutrients that are important for strengthening your muscles and connective tissue and that help with the production of essential hormones and neurotransmitters.

To cut a long story short: IIFYM is a drastic oversimplification of dieting for bodybuilders and anyone else. While it might be alluring to think dieting could that be simple, this is unfortunately a somewhat trigger-happy application of Occam’s razor…


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