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The Science Behind IIFYM & Why Low Calorie Diets Suck

Your body is constantly trying to maintain itself through a process called homeostasis, so if you eat at 1200 calories a day your body will try to adapt to only needing 1200 calories a day. This will make weight loss harder and is why people plateau on low calories diets. It also makes you more likely to binge which leads to slower progress and a poor relationship with food.

To calculate your macros I calculate your BMR and add in your exercise to come up with the calories you burn each day (this is called your TDEE). This is your maintenance numbers or how much you’d need to eat every day to maintain your current weight. Based on this number, I put you at a deficit (anywhere from 200 calories to 600 calories per day, depending on how much you have to lose) so you can lose 1-3lbs per week (again it all depends on how much weight you have to lose). You’ll be able to sustain this weight loss and not plateau as we’ll slowly decrease your calories as you lose weight and your BMR decreases. This will also set you up to be WAY less likely to binge because you’ll be able to fit in some treats and won’t feel so restricted.

The reason we track the macros as opposed to just calories is to target fat. If you were to only track calories you’d lose fat and muscle. With IIFYM you’re targeting fat because you’ll be eating a certain amount of protein to keep you at a positive nitrogen balance, which simply means your body will be able to repair your muscle and you will not lose muscle, only fat. This will allow you to get a completely different body shape than if you were to lose fat and muscle, which will give you that skinny fat look and just make you look deflated.


Macronutrients include fat, carbohydrates, and protein. They are vital for fueling your body and needed in large amounts. Macronutrients make up your total calories. 1 gram of fat is worth 9 calories, 1g of carbs is worth 4 calories, and 1g of protein is worth 4 calories. Micronutrients include necessary vitamins and minerals. Fiber is a carbohydrate that should also be tracked, fiber is not only beneficial for your internal health but it also gives you a more accurate indication of progress. If you don’t eat enough fiber you’re likely going to experience bloating which will sway your measurements or the number when you step on the scale. If you want to learn more about the role each macronutrient plays check out this article.

Customizing your Macros

Your macros depend on your age, weight, height, activity level, and goals. There are calculators online like www.iifym.com/iifym-calculator or www.whataremymacros.com. Considering there are so many factors to look at and especially if the individual has more than 30lbs to lose, sometimes the online calculators need adjusting. That’s where coaches come into play. We highly suggest knowing your coaches qualifications before purchasing services. Ask yourself, “does this person have experience with customizing other people’s macros?” “Are they certified and allow to recommend someone’s macronutrients?” Personal trainers are typically taught how to calculate a person’s caloric needs as well as a proper macro split but it’s still a good idea to know someone’s success rate.

Tracking your Macros

Many people track macros using MyFitnessPal but there are other websites and applications like Lose It and Macros +. MyFitnessPal has the largest database available for searching foods but it is also user submitted so you must always double check the label with the entry. To input your custom macros into MyFitnessPal you can either purchase the premium version or try this script on Google Chrome: http://foodfastfit.com/#/howdy

Why I love IIFYM

I started practicing IIFYM in March of 2013 after counting calories for close to a year. I was only eating 1200-1300 calories and felt like crap. The only workout I had energy for was a mindless hour on the elliptical machine. I was bingeing at least once a week and although I was losing some weight I wasn’t seeing my body transform like I had hoped. Once I began IIFYM I started eating around 1,700 calories. I was still losing fat at this amount because I was working out hard and at a proper macro split. I ended up losing the last 35-40lbs of the 100lbs in less than 6 months. Then I bulked for 3 months to build more muscle, which I followed with a 3 month cut where I was able to consume almost 1,900 calories and still blast fat. I reached my lowest weight, 121lbs, at this time while lifting the heaviest I ever had. I now lift weights 4-5x a week. A year ago I couldn’t imagine working out the way I do now because I exert so much more energy and I wasn’t fueling my body enough back then. Food is a friend and IIFYM has helped me realize this. It has also helped me find balance in enjoying the foods I like and made me appreciate the importance of moderation. I’ve lost 35-40lbs following IIFYM, but my body has completely changed shape.


iifym macros cellulite thighs

See all my progress pictures here.

The heat on IIFYM

IIFYM gets some heat in the fitness community mainly because some people assume it means you can stuff anything you want in your mouth. Well, I don’t know about you guys but unfortunately when I count my macros I cannot fit a breakfast of donuts, lunch of fried chicken and french fries, and dinner of pizza into my macros. With IIFYM you have flexibility. You may be able to fit that donut in for breakfast but if you’re going to fit your macros for the rest of the day that means lower fat and high protein items (baked chicken or fish). IIFYM is great for learning how to balance treats with the nutrition your body needs to lose fat and be properly fueled.

Refeed Day

If you’re familiar with IIFYM you may have heard the term refeed day. A refeed is completely optional and simply a psychological tool to help you stay on track. A refeed day is one day out of the week where people eat anywhere from 30-50% more carbohydrates than usual. This gives you a day with a little extra flexibility. Some people choose to eat a little extra fat on this day. It’s really up to you. Find whatever works for you to stay on track and keep you from binge eating or overeating.

Intermittent Fasting

Intermittent fasting is another optional tool popular among IIFYM followers. For most people, intermittent fasting means consuming all their calories in an 8 hour period. Personally, I practice IF because I’m not hungry in the mornings and I like to enjoy a big treat before bed. So I consume all my food between 2pm to 10pm. Again, this is simply psychological and is not proven to help you lose fat faster. From the research I have found neither a refeed day or fasting promotes fat loss aside from the fact that they can both be a tool to helping you stay on track. I utilize both.

Macro Consultation

If you are new to dieting and feeling overwhelmed or if you are relatively overweight consider purchasing my macro support before setting out to customize macros on your own. I provide you with your custom macros as well a plethora of resources for you to succeed. I’ll answer any questions or concerns you have during this time. By the end of the program you should have the tools necessary to customize your own macros. You can choose to purchase one on one coaching if you need accountability and extensive support.

If you are interested please fill out this form and I will contact you within 48 hours to begin.

Fill out my online form.

I hope this answers any questions you all had on IIFYM! If not, feel free to drop a question in the comments below or email me. I know the feeling of being lost or overwhelmed by all this. Knowledge is power so do your research and know that as long as you are making healthy choices you are on the right track!


weight loss before and after

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5 thoughts on “IIFYM

  1. Jaz
    Jus wondering, what is the actual price for you program? You have listed two prices in this post $25 & $50.
  2. nofIningPhith
    Hello! My name is Gwen Maxey and I live in Elgin,IL. I have read your blog post about IIFYM or "If it Fits your Macros" Broken Down and I want to say that I am quite impressed with your professionalism on the subject!
  3. K Tomlinson
    This is a great article I really enjoyed it! Im currently doing IIFYM ans I love it. My goal is 100lbs weight loss as well. Did you have loose skin? Im a little discouraged for this reason. I know i might have it but I just wan to hear from an actual person to help me get my perspective straight :) thank you!
    1. malzisfit@gmail.com Post author
      I do have some loose skin but not nearly as much as I imagined or as much as I've seen from other 100lb transformations. I recommend having a solid weight training routine and to keep your protein around 1g per lb of bodyweight once you're within 20lbs of your goal weight. The more muscle you hold on to the tighter you'll look. :)

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