IIFYM: The Good, Bad, and the Ugly

Some have renamed it "flexible dieting" to send a more moderate message since it's gone so far off course, but when IIFYM got its start the idea was fairly reasonable.

IIFYM gave dieters a little more leeway and removed the idea that certain foods were off limits. The main thing it had going for it was that you could still reach your physique goals even if you indulged a little or chose foods that weren't the bodybuilding standard.

There was no need to stress about having a white potato instead of a sweet potato. Either was fine as long as it fit within your nutritional budget: your predetermined allotment of protein, carbs, and fats, and of course total calories.

If you wanted to eat mac and cheese along with your chicken and simply fit the macros for a serving into your diet, no biggie. You'd make the same progress as you would have with chicken breast, rice, and some almonds. The dieter could stop fearing food sources that weren't a detriment so long as the calories and macros fit into their nutritional budget.

This simple approach ended up getting taken out of context as an "eat anything you want because the source doesn't matter... if it fits your macros." Maybe that's not what the originators intended, but just peruse Instagram and Facebook and you'll see the IIFYM clones all posting photos of their meals consisting of chicken, ice cream and exactly 1.2 Twinkies, carefully weighed and measured.

So instead of being IIFYM it became IDM-IIFYM-OK (it doesn't matter; if it fits your macros; then it's ok). And that's where things got really confusing, wrong, and flat-out stupid. Coaches who endorsed this belief could be found telling clients and competitors that 100 calories from Oreos is the same as 100 calories of broccoli. That actually still happens.

Their reasoning? "It's all about calories in and calories out. And all food sources are equal if the number of calories and macronutrients are equal... as long as you're in a calorie deficit, weight loss will occur."

This belief intensified when people started using everything from fast food to candy bars and kids cereal to prove a point about food sources not mattering for weight loss. And they were right... sorta.

Weight loss is possible that way. Initially at least. Anyone can lose weight eating high calorie foods, but what happens is that to stay within the caloric budget, they have to eat a lot less volume than they would with lower or moderate calorie foods.

This approach isn't terribly innovative, is it? Weight Watchers was the original IIFYM. They just used a "point system." And if you didn't exceed your points for the day, you'd be in a caloric deficit and weight loss would occur. But would it remain, and what about body composition?

Most lifters who want to improve their body comp don't care about "weight" loss. They care about fat loss, muscle retention and growth, and long term leanness.

The issue with eating crap and allowing some of that crap to displace nutritious food is that your appetite changes, your brain changes, and your gut microbiota changes. These physiological changes can make it very difficult to continue eating small portions of junk and staying within the macronutrient and calorie allotment. These changes also make it harder to enjoy nutritious food – you know, the stuff that satiates and makes you feel full.

But nobody needs to tell you that your preference for quality food decreases when your exposure to shitty food increases. This is an obvious occurrence: People who eat mostly healthy food tend to prefer mostly healthy food. People who eat mostly shitty food have a hard time appreciating the healthy stuff. There have been studies. Look them up if common sense isn't good enough.

Sure, the machine that measures calories as a unit of heat (a calorimeter) tells us that a calorie is a calorie. But this doesn't hold true for the human body. Why? Because it's a superficial argument that doesn't address the unintended consequences of paying attention to ONLY calories and not their sources. The human body doesn't work the same way as a calorimeter.

Not all calories are equal, and not all macronutrients are the equal. The source makes a difference.

From an energy perspective, one gram of fat is numerically one gram of fat, no matter where it comes from.

Fats digest more slowly than carbs, but take virtually no energy to be broken down in digestion, which means there's no TEF, or thermic effect of food. Your body doesn't "spend" many calories assimilating fat into the body. Luckily not many people eat just a stick of butter.

But you don't want to cut fats out completely. Certain fats can have anti-inflammatory effects (Omega-3s for instance), they're responsible for helping you absorb essential nutrients, and your hormones, metabolism, and sex drive depend on them.

But there are fats that can cause inflammation and are linked to heart disease, strokes, and type-II diabetes. And according to researchers, certain dietary fats can impair insulin sensitivity and actually make it harder for you to lose body fat compared to other types of fat. Their energy value may be equal but their effects on the body are vastly different.

So if the fat you choose to fit into your daily allotment is coming from deep fried sources and prepacked snack cakes, is it the same as meeting that quota with fat from egg yolks, avocados, walnuts, and salmon? Don't think for a second that it is.

Proteins digest at the highest thermal rate of the three macros. About 30% of the calories you eat from protein are used for digestion. This is one of the biggest reasons that the "calories in, calories out" theory is BS.

The calories you get from protein actually make the body work to break them down. So eating a 400 calorie plate of fish is going to be dramatically different than eating a 400 calorie plate of pasta. A calorie is not just a calorie because of what happens to your body and your appetite as a result. And while most IIFYM dieters know the value of protein, this blows up the debate coming from people who say that a calorie is just a calorie.

The other thing about calories from protein – it's very hard to eat an excess that will make you fat. You can't say the same about an excess of calories from carbs or fats. When you eat more protein than what's allowed on your diet, it will likely not make a dent... unless you're eating it in the presence of extra carbs and fat.

Protein calories in excess are not metabolized by the body in a manner similar to carbohydrate calories. One study demonstrated that a relatively higher amount of protein doesn't contribute to an additional gain in fat mass. And if the findings from this study are true, then the need to be anal retentive about tracking protein down to the gram is absurd.

The thermic effect of carbs is a lot lower than protein, but that number varies depending on the source. Higher quality carb sources come wrapped in nature's packaging containing some fiber and water: broccoli, oranges, cucumbers, and even potatoes, for instance. There are also carb sources, that, when prepared, soak up a ton of water, volumizing the mass of a food without increasing its calories (think oats and beans).

These are examples of carbs that contribute to your satiety. They're nutritionally dense without being calorically dense, which means they fill you up. Do you think the carbs coming from pinto beans are the same as the carbs coming from jelly beans? Even if your calories were equal for both, their effect on your body won't be the same.

Foods high in refined sugar spike insulin quickly and make you crave more of the same... even after you've reached your IIFYM allowance. Sugary foods, especially when they're combined with some salt and fat, don't satiate. They're not meant to because food manufacturers designed them that way. They'd like for you to keep eating and keep buying their products. So when you post pictures of your nighttime Oreo and ice cream habit, you're not being edgy or clever, you're just being a dumb consumer.

These kinds of foods light up the same parts of the brain (the nucleus accumbens) that cocaine, heroin, and morphine do. They flood the brain with dopamine, making you want more.

Have you ever met a person who said they just couldn't stop eating plain baked potatoes, broccoli, oats, beans, or even rice? Most likely not. But you probably have known people who can always fit in more dessert. You may be one of them.

So while a calorie is a calorie in the most basic of definitions, to pretend that all food sources are of equal value from a quality of health perspective, or that total calories are all that matter, is ignorance.

1 It Creates Fanatics Who Can't Think For Themselves

To do the diet you need to learn to weigh and measure your food so that in time, you can eyeball a portion of food and know the rough estimate of the macronutrients you'd be getting.

But in order to have the ability to manage your macros without obsessing over them, you have to be a little obsessive. You must go through the routine of weighing, measuring, and tracking everything you eat to get an accurate read on what you're consuming.

This is what many would consider obsessive, and it'd be fine if it were temporary. Eventually you shouldn't need to measure food or wonder if you're drastically over or under your intake of carbs, protein, or fat.

But often the IIFYM dieter doesn't stop weighing, measuring, and micromanaging. They can't graduate from the obsessive part into normal healthy eating. They lose touch with common sense and can't feed themselves without consulting an app in their phones first.

If you've never gotten a reality check on portion sizes, you probably should at some point. It's good to weigh and measure for a time. But being unable to eat without psychotically typing your food into your phone isn't a super healthy way to live.

2 It Ignores Gut Health

You can fit junk into your allotment of macros or you can fit high quality food into the allotment. It really comes back to the dieter.

But if an individual believes that the only thing that matters are macros and calories, he or she will tend to stop caring about the consequences of the food sources. It's possible of course to do IIFYM and leave out shitty foods in favor of quality ones. Hell, bodybuilders have been doing that for decades, long before any acronyms were created.

The problem is, most people ignore gut health. Huge mistake. Gut health is probably the place everyone should start before scribbling down their macros or diet.

Roughly 80% of your immune system is contained in the digestive tract and efficient nutrient absorption starts in the gut too. But if that's not exciting enough for you, realize that the microbes in your gut play a big role when it comes to cravings. If you eat healthier food, you feed the bacteria that makes you crave healthier food, which will make it easier to stick to a diet.

But keep the junk in your diet and you feed the bad gut bacteria that increases cravings. Gut bacteria doesn't give a shit if it fits your macros.

3 It's Actually Not Ideal For Contest Prep

I know that IIFYM dieters will point to some people that got in amazing shape for shows using this approach. Sure. But the great majority of bodybuilders who have to get as peeled as possible know that deviating from what works for them is a recipe for disaster.

Yes, there are exceptions, but most men can't get away with substituting certain food choices for others just based on macros fitting in during contest prep.

The reason most guys headed into a contest carry prepared food around with them is because they know their body, and what they can and can't eat in order to get extremely shredded. And in order to do so, almost all of them have to narrow down their choices to a select few items.

This is one concept that a lot of people don't understand if they've never dieted down to extremely low body fat levels. Going from 20% body fat to 10% isn't really all that difficult. You can most definitely apply an IIFYM approach, manage your calories properly, and accomplish that. However going from 10% body fat, to 8% is a little more tricky. And going from 8% body fat to 5% requires an exceptional amount of discipline, and really just doesn't allow for most people to deviate from a narrow set of food choices.

If you're a person who can get away with doing so, that's great. You won the genetic lottery in that regard. Most people will find that to get down to extremely low body fat, food sources have to eventually be narrowed down to the usual stuff: chicken, broccoli, egg whites, etc.

Now, this may not apply to the average bikini or figure competitor because women are judged by a different set of criteria. But if you're a male trying to get into serious contest shape, then you'll need to know a lot about how your body responds to different food sources. Especially on contest day.

4 It Ignores Micros

Most people, even those who are fairly meticulous about their diet, ignore micronutrients. They think it's all about them gainz, so all they need is the right ratio of protein, carbs, and fat.

Nope, sorry. Micronutrient deficiencies, like Vitamin D and magnesium deficiency, can really impede your goals. And what may begin as an inability to recover can end up as a health crisis. Throwing a Centrum down your throat on occasion won't get the job done, and in order to figure out why you feel like shit you'll have to go get blood work and find a smarter doctor than the GP.

But an IDM-IIFYM-OK guy who thinks 400 calories from a Big Mac is the same as 400 calories from kale and turkey probably isn't going to care about pesky micros.

IIFYM was never intended to be a pro-junk food diet. It was simply intended to allow for people to choose foods outside of a small selection of traditional "clean" foods and still meet their physique goals.

Like most good ideas however, it became bastardized by those who took it to extremes and tried to make a case that all food choices were equal as long as a calorie and macronutrient quota was met.

It's possible to be a smart IIFYM dieter who reaches their dietary budget through quality, whole foods. But he or she also is aware of food sources, their impact on gut function, and their contribution of micronutrients. The smart IIFYM dieter is also not merely after weight loss, but rather improved body composition and improved behavior around food – which doesn't include an ongoing lifelong obsession.

Don't like this perspective of IIFYM? I have another acronym just for you: IDGAF.

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