The premise of flexible dieting or IIFYM (if it fits your macros) is that you eat the right number of calories for you and in the right proportion of macronutrients. You calculate how much of the macronutrient categories you should be eating and then choose what to eat based on those targets. There are three macronutrients—protein, carbohydrates, and fat. Micronutrients, the vitamins and minerals in your whole foods (fruits, veggies, grains, lean meats etc) aren’t considered in this way of eating. From a health standpoint, you should consider micronutrients. But IIFYM offers flexibility for those who want to reach a certain goal like fat loss or muscle gain or even maintain their current physique while enjoying foods like pizza, burgers, oreos etc-foods typically considered bad on many diets.
The benefit of following IIFYM is that it teaches you about food and portions. It blows a hole in the notion that you can only eat ‘good’ foods to get lean, or whatever your goal is. No food is inherently ‘bad’ and any food even ‘good’ foods will make you gain weight if you eat a surplus of calories for what your body needs. You can eat pizza every day if you want to, as long as you calculate the calories and macros and adjust the rest of your daily intake around it. For many people, this is very freeing. But since all foods contain macros you’ll need to work closely with a macro tracking app so you know you’re staying on track with your target food intake.
This is why flexible dieters typically use an online calculator or app to calculate macros, which takes into consideration your physique goals. Once you figure out what your macro targets are, you’ll need to start to track them so you can hit your daily goals. As with any diet, there are pros and cons. So let’s break those down.
IIFYM or flexible dieting is just that, flexible. All foods are ‘allowed’ as long as they fit into your macros ratio. But the reality is that logic also applies to the OG tried-and-true weight loss method: counting calories. Remember it’s possible (though not advised) for some folks to eat 1,500 calories in Twinkies® every day and still lose weight because that’s under their daily intake needed for fat loss. Is a Twinkie diet “healthy”? No, yet someone could potentially drop a few pounds (maybe even more). Though research suggests it may not be ideal to help you keep that lost weight off.
The biggest pro of this way of eating is that it allows for flexibility and people can maintain this for life. Whereas other diets are so strict that people often rebound to worse than they were before the started the diet. If you want to drop some pounds, learn more about food and get a good idea of how to ‘eyeball’ it and not totally hate life because of your restrictive diet, then IIFYM is worth trying.
Perhaps the biggest con or negative is that the core principles behind IIFYM is that it doesn’t automatically lead you to a healthy diet. For example, all carbohydrates are essentially equivalent—you’re counting grams of carbs so it doesn’t matter if you eat Oreos or whole grain brown rice and fiber-rich raspberries? You can adhere perfectly to the macro ratios while still eating junk (probably adding in some protein to hit that target…but anyway…)
That said, some IIFYM plans available encourage you to eat more whole, unprocessed foods and that typically means less junk, and fewer of those nutrients like sodium and sugar, which we should be limiting. This is my prefered approach because if you want to truly transform your body and health you need to eat good foods but not be so restricted you binge on junk regularly. That isn’t getting you anywhere.
There are many ways to determine your macro ratio and find what works best for your body and your current physical goals and activity level. You can adjust protein, fat and carb levels based on your body’s response. A big benefit is that you’re tracking what you eat and research shows this can make shedding fat more successful.
For anything to be successful, you have to stick to it. Research shows that weight loss studies that compare different diets find there is little to no difference in how much weight was lost in participants across different diet groups. So basically, if you’re in a caloric deficit and exercising for an extended period of time, you will lose weight. Many people get caught up in thinking there is only one way, or this diet is better and surely going to give them the results they seek. The fact is, it doesn’t matter what diet it is. You need to learn how to eat so you gain knowledge about what you are doing and how to maintain it.
Ok so let’s circle back to the question-should you try IIFYM? If it intrigues you, and you want to lose some weight or shave a few body fat percentage points, go for it because you’ll likely find success for above mentioned reasons For the sake of your overall health (your heart, your blood sugar, your disease risk), take quality of food into consideration, too, and err more towards eating healthy foods to hit your macro targets. But just know that you can fit in those Oreos you’ve been craving without derailing your progress.
Do you need help getting started with your fitness goals and someone to keep you accountable? Check out my 30 Day Body Boost program!