If you’ve only briefly heard of flexible dieting (or IIFYM; “If It Fits Your Macros”) before, the first thing to know is that it does away with traditional calorie counting and watching exactly what it is you eat. In actuality, it’s a nutritional concept that lends flexibility to the kinds of foods you can eat while still being able to achieve your body specific goals. You mean I can have my cake, and eat it too? That’s right. You can still have some of your favorites daily as long as the macro fits. Hello doughnuts, my old friend!


How It Works

Flexible dieting focuses solely on tracking the amount of macronutrients (fats, carbohydrates, and proteins) in the foods we eat. Having the right ratio of fats, carbs, and proteins allows our bodies to maintain energy and create muscle growth. No matter what diet you currently follow, macronutrients can be found in every meal that you eat because it is an essential component of all foods. This holds true whether you’re having healthy grilled chicken and brown rice or decadent desserts like cupcakes and ice cream.

Flexible dieting shifts the focus from the body recognizing food as either healthy or unhealthy, but instead on how the stomach breaks down and processes macronutrients solely. The very essence of IIFYM is that it recognizes that a tuna salad with the exact same macro makeup of a double cheeseburger will achieve the same results in your body composition. By counting macros, you are aware of how your body processes food and the specific result it will have on your body.

Counting Macros

The amounts of macronutrients we consume can be easily identified in relation to the daily calorie amounts we’re used to seeing. However, this is not your typical calorie counting. In the three main macros (proteins, fats, and carbohydrates), one gram has a specific calorie value assigned to it.

Macro calorie breakdown chart


One gram of protein = 4 calories

One gram of carbohydrate = 4 calories

One gram of fat = 9 calories

So while in traditional calorie counting, where you simply add up the calories from the different foods you eat to reach a target goal of 2,000 calories a day, flexible dieters will use macros to reach that same calorie amount.

Counting macros to reach a targeted daily calorie amount:

150g of proteins = 600 calories

170g of carbohydrates = 680 calories

80g of fat = 720 calories


Total calories via macro counting: 2,000 calories


What’s the Benefit?

For one, variety. With flexibility dieting, you learn how to make the foods you love work for you and your fitness goals. There is less guilt when you do finally reach for one of your favorite snacks because you’ve allowed for it. Another benefit is that it’s sustainable. Traditional diets commonly label bad food days as “cheat days”, but many of us aren’t proud of that term. When you feel like it’s okay to have certain foods in your diet, you are less likely to binge and fall off the deep end and follow through. Flexible dieting is also convenient. The restrictions are less heavy when going out for social gatherings or worrying about to have for lunch at work this week.

Common Misconceptions

A huge misconception of flexible dieting is that you can eat nothing but junk and somehow still achieve all of your fitness goals. The key difference in flexible dieting is that you can still have a treat in your diet if the macro makeup of it makes sense. The important thing to remember is that in IIFYM, macronutrients are the focus. Sugar levels, fiber, and other micronutrients should also be watched closely for specific body and health goals.

Getting Started

Set your goal

First, be aware of your total daily energy expenditure (or TDEE), which is simply a summary of everything your body does, actively and passively, to burn calories in a day, in relation to your current weight and exercise habits. From there, calculate the amount of macros you can have in a day to reach your fitness goals.

Use available resources

Since flexible dieting is all about measuring macros, it’s important to find a practical way to track these amounts daily. These online resources offer just that and are personalized to fit your needs, as well as having a community of likeminded IIFYMers there to support you.

using an app for flexible dieting

If It Fits Your Macros (IIFYM) website is a comprehensive flexible dieting site including over 700,000 members. It offers IIFYM programs, guides, and helpful articles.

Working Against Gravity is a company that offers online couching services with flexible dieting programs that will get you to feel confident in counting macros in no time.

MyFitnessPal is a free app used to track macros that is a favorite amongst flexible dieters. It makes macro-counting simple and also includes the world’s largest nutritional database. Available in iOS or Android.

My Macros + is a specialized app made strictly for counting macros that’s designed by people who lift weights. It includes a detailed IIFYM-style macro tracker. Available in iOS or Android.

Get a scale

To track macros more efficiently, it’s helpful to use a food scale to get the accurate amounts down. While food packaging includes detailed information, a scale can ensure that serving size is right. This is especially helpful when cooking and tracking meals at home.

With any diet, it’s important to find ways to make it work for you. The great thing about flexible dieting is that it uses the very notion of being able to sensibly have what you want while still being able to move forward toward your body specific goals. Since it uses a method to fit many of our normal eating habits into our diets, it’s more of lifestyle enhancer rather than a complete diet overhaul. Many of these dieters find that the less restrictive nature of IIFYM allow for them to stick with it, as opposed to traditional yo-yo dieting where binge eating and the emotional instability to carry on are a major cause for them to fail. Flexible dieting bridges the gap by keeping things in moderation and finally striking a healthy balance between “good” vs. “bad” foods. Here’s to getting our macros on!