About IIFYM – The Original Macro Calculator Since 2012
Over 10 Million Macros Calculated
IIFYM.com is home to the world’s first macro calculator, created in 2012 by founder Anthony Collova. What started as a simple tool built for bodybuilding prep became the foundation of a global movement that changed how millions of people approach weight loss.
IIFYM stands for “If It Fits Your Macros,” a flexible dieting approach that allows people to lose weight while still eating the foods they love. Instead of restrictive meal plans and banned food lists, IIFYM focuses on hitting personalized protein, carbohydrate, and fat targets that create a sustainable calorie deficit.
To date, the IIFYM macro calculator has been used more than 10 million times. It is used approximately 5,000 times per day by people around the world looking for a smarter, more sustainable approach to fat loss.
Every calculation and nutritional recommendation on IIFYM.com is reviewed and approved by our Expert Review Board, which includes Dr. Ioannis Nikitidis, MD, RD and Justina Serwaah Owusu, RDN.
Dr. Ioannis Nikitidis, MD, RD – Medical Reviewer
Dr. Ioannis Nikitidis is a licensed physician and registered dietitian who serves as a medical reviewer for IIFYM. He reviews all macro calculator formulas, calorie recommendations, and metabolic adjustments to ensure they meet evidence-based medical standards.
Justina Serwaah Owusu, RDN – Registered Dietitian Nutritionist
Justina Serwaah Owusu is a Registered Dietitian Nutritionist and a graduate of Florida International University. She reviews all nutrition guidance, macronutrient recommendations, and educational content on IIFYM to ensure accuracy, safety, and long-term sustainability.
All calculator outputs and nutrition recommendations on IIFYM.com are reviewed and approved by the IIFYM Expert Review Board.
Meet the Founder
Anthony Collova, Creator of the Macro Calculator
Anthony Collova is the founder of IIFYM.com and creator of the world’s first macro calculator, which he launched in 2012. His work pioneered the flexible dieting movement and fundamentally changed how the fitness industry approaches nutrition. The IIFYM methodology Anthony developed is now standard practice among evidence-based nutrition coaches worldwide and has been credited by health publications as popularizing flexible dieting globally.
Anthony has over 30 years of experience in fitness, starting his journey in 1995. He has competed in 12 NPC Men’s Physique competitions, placing 1st twice, 2nd twice, and 3rd three times. For his competition prep, Anthony trained under Dr. Layne Norton, PhD, one of the most respected names in natural bodybuilding and nutrition science. This mentorship shaped Anthony’s evidence-based approach to flexible dieting and informed the formulas behind the IIFYM calculator.
Over the past two decades, Anthony has personally coached more than 500 clients through his VIP 1-on-1 coaching program, working primarily with busy executives seeking sustainable fat loss. The systems and calculators he built have helped over 50,000 people calculate and track their macros.
Anthony developed the proprietary formulas behind the IIFYM macro calculator, incorporating adjustments for metabolic adaptation, activity level, and individual body composition that generic calculators miss. He has also built over 150 macro calculators for other websites, companies, and nutrition coaches worldwide, making him one of the most experienced macro calculator developers in the industry.
A serial entrepreneur, Anthony also founded MyOatmeal.com, a custom oatmeal company he later sold. He has been featured on the Dynamic Lifestyle Podcast, Dynamic Duo Training, and the Recovery Authors Podcast.
Throughout his career, Anthony has collaborated with and interviewed leading experts in nutrition and fitness, including Dr. Layne Norton, PhD, Alan Aragon, Dr. Joe Klemczewski, PhD, Tyler Mayer, IFBB Pro, and Brandan Fokken, IFBB Pro. These conversations have helped shape IIFYM’s evidence-based approach to flexible dieting.
Beyond fitness, Anthony brings 28 years of sobriety to his coaching philosophy. His personal experience with addiction, recovery, and transformation informs his approach to helping others overcome the mental and emotional barriers that prevent lasting change.
While not a credentialed medical professional, Anthony works directly with the IIFYM Expert Review Board to ensure all calculator outputs and nutritional recommendations meet evidence-based standards. Every formula and recommendation is reviewed and approved by Dr. Ioannis Nikitidis, MD, RD and Justina Serwaah Owusu, RDN.
View Anthony’s full credentials
My Story
By Anthony Collova
Where it all started
Once upon a time, people didn’t track macros to lose weight. Instead, they ate magical “clean” food 6 times per day, which made them unhappy. And that is where my story begins.
How drug addiction, ADD, and divorce helped me lose 70 lbs and find my purpose
My name is Anthony Collova. I am the founder of IIFYM.com and the creator of the macro calculator you used yesterday. I’m also the creator of over 150 macro calculators currently being used on websites by various companies and nutrition coaches around the world.
I’ve been doing this since 2012, and I’m damned good at it.
About 20 years ago I found myself 3 years sober and divorced. My wife grew tired of being married to an overweight slob, so she sought attention elsewhere. And I sought attention in peanut butter covered waffles with ice cream on top.
Next to getting sober, being betrayed and alone was the most difficult and painful thing I had ever experienced. Maybe even worse because there was nothing I could do about it. I couldn’t get her back, and knew that I shouldn’t anyhow.
I was torn up, inside and out. This was not how I imagined my life would end up.
Depressed, alone, and unable to cope with my pain, every day that went by I ate more and more food and began hating my reflection in the mirror. I was lonely and hurting and desperately wanted someone to love me. If I’m honest, I actually just wanted someone to hold. Someone to talk to.
I wasn’t ready to start dating again but I knew that if I didn’t make some changes, I’d never attract the right kind of person into my life.
So I got to work and set out to lose the weight my ex-wife always complained about.
Hell, I already changed my entire life when I got sober. How hard could losing a few pounds be?
Yeah. So… turns out, it’s really hard. Or rather, it was for me at the time. Now, burning fat is super easy.
Determined to rebuild my life and my body, I kept at it
Every day I’d read the nutrition blogs and websites, trying to figure out what the secret was. There had to be one. I just knew it.
I interviewed the best doctors, dietitians, and specialists I could find. I hired the most popular diet coaches around and signed up to compete in bodybuilding.
That’s when I found Dr. Layne Norton.
Layne was already making a name for himself in the natural bodybuilding world. He had a PhD in Nutritional Sciences, was publishing peer-reviewed research, and coaching some of the top natural bodybuilders in the country. I knew if anyone could help me figure this out, it was him.
I hired Layne to coach me through my NPC Men’s Physique competitions. Working with him changed everything. He taught me the science behind metabolism, the importance of reverse dieting, and why most people fail by eating too little, not too much. The evidence-based approach he drilled into me became the foundation of everything I would later build at IIFYM.
Over the next several years, I competed in 12 NPC shows and stepped on stage more times than I can count. But more importantly, I finally understood how fat loss actually worked.
I spent years dissecting the info and meticulously assembled it in a way that made sense in my head.
See, I’ve got some pretty sweet ADD so I don’t learn in the same way that most people do. I’ve struggled with this my entire life and eventually overcame that too.
As it turns out, the learning disability that haunted me as a child would be the key to finding my purpose and passion as an adult.
As I scoured over all the before and after results I could find, I’d get more and more excited, closer and closer to figuring it all out. Over and over I’d obsess over the smallest of details until finally, I could picture it in my mind.
That’s how I learn. The pictures in my head have to make sense. Until that happens, nothing in my life works. Again, it’s a curse and a blessing.
The breakthrough
Once I was confident that I figured out the secret to immediate and sustainable fat loss, I tested it out on myself. At 70 lbs overweight, I started the program that I spent forever obsessing about.
The first thing I did was remove the batteries out of my scale.
My research told me that in order to burn fat, I had to increase my metabolism and stop starving myself. But this meant that I needed to increase my carbs to levels I really wasn’t comfortable with.
God this was scary.
I mean, I knew the science part of my program was strong enough, but was I? Did I actually have the discipline to follow the diet I spent so much time perfecting?
As it turns out, the dedication was the easy part. The tricky part was actually eating enough carbs to make it all work.
And that was the key. Carbs.
The exact opposite advice that most every so-called expert preaches. The exact opposite approach the media promotes. And the same exact food everyone always told me to avoid.
Pasta, bread, rice, potatoes, sugar.
Unlike every other fad diet out there that wanted me to reduce carbs and tank my energy level, my program had me do the opposite and eat as many carbs as I could get away with, in order to turbo charge my metabolism.
Scary stuff for sure, but once I realized that I could spike my carbs from a few glasses of orange juice, things got much easier and fun. Something I thought dieting would never be. Fun!
Every morning I’d start my day with a tall glass of OJ and end with an even bigger glass right before bed.
Two weeks later, I pulled the scale down off of the shelf in my closet. I must have been staring at it for a full minute before I realized I had been holding my breath.
“Screw it. You don’t own me.”
I stepped up, gave it a second, and with one big exhale I looked down.
4 lbs lighter!
4 lbs lighter while eating twice as many carbs as I thought I could. 4 lbs lighter while drinking sugary orange juice right before bed. 4 lbs lighter while eating more food than I had ever thought I could.
Now, I don’t want to type out all of the curse words I shouted at the scale that day. But as I stood there, pointing my finger at it, I knew that the scale no longer owned me and I would forever be in control of my weight, health, and happiness.
It took 6 months for me to drop 50 lbs, but in that time I totally transformed my body.
Testing and refining the system
I spent the next 2 years dialing in the strategy to create a system that would work for anyone, at any time. I absolutely had to prove to myself that it was not a fluke. That I wasn’t some sort of special case. That anyone that followed the same steps I followed would get the same, predictable results.
Over those 2 years I tested my system on over 500 people. Clients that I worked with in exchange for feedback.
I adjusted where required, keeping the techniques that gave busy people the most leverage possible and ditching the rest.
If it didn’t make logical sense, I tossed it. If it was confusing, I canned it. If it didn’t yield massive results to everyone, I didn’t keep it.
In other words, I only wanted my clients to implement the most effective and easy to follow parts of the system, so that anyone at any level could lose weight. It had to work for everyone, regardless of their genetics, regardless of their hormones, regardless of their schedule, regardless of how many diets had failed them before.
This meant keeping things simple. Showing busy people how to lose weight while eating the foods they love, with or without exercise.
Launching IIFYM
Once I successfully did this for 500 clients, I started charging people. Mostly busy executives that wanted immediate results and didn’t have time to waste on a strategy that slowed them down or didn’t provide massive results.
Because my system was rock solid, I was able to charge my VIP clients $1000 per month for my coaching services. I learned early on that the more I charged, the more people were successful since the money they spent held them accountable to their goals.
Eventually, the daily stress of working with high level executives added up, so my days of 1-on-1 coaching came to an end. Don’t get me wrong, I still wanted to help people. I just had to protect myself from the emotional stress.
It wasn’t long after that I decided to share my system with the world without the 1-on-1 coaching.
In 2012, I built the IIFYM macro calculator and started helping other busy people learn how to lose weight while eating the foods they love.
Over a decade later, the IIFYM macro calculator has been used more than 10 million times and gets used about 5,000 times per day. I am always making improvements based on feedback so that I continue to help as many people as I can.
I’ve since built over 150 macro calculators for other websites, companies, and coaches, and together, we are changing the world.
It has been an awesome ride and it is only getting better.
IIFYM Milestones
1995 – Anthony begins his fitness journey
1997 – Anthony gets sober, beginning a recovery journey now spanning 28 years
2005 – Anthony begins his transformation, losing 70 lbs using the system that would become IIFYM
2005-2011 – Trains under Dr. Layne Norton, PhD. Competes in NPC Men’s Physique. Tests and refines the IIFYM methodology with 500+ clients
2012 – Launches the world’s first macro calculator on IIFYM.com, pioneering the flexible dieting movement
2012-2019 – IIFYM grows to help millions of people track macros for weight loss. Anthony interviews leading experts including Dr. Layne Norton, Alan Aragon, Dr. Joe Klemczewski, and Brandan Fokken
2019 – Surpasses 10 million macro calculations
2024 – Establishes Expert Review Board with Dr. Ioannis Nikitidis, MD, RD and Justina Serwaah Owusu, RDN
2025 – Launches Macro Max, IIFYM’s own macro tracking app for Android and iOS
Get Started
On average I get about 200 emails per day from people that use my calculator. Busy people that want to lose weight while eating the foods they love.
Almost everyone asks the same 3 questions:
- Are these macros right? Can I really lose weight eating this much food? Learn why IIFYM gives so many calories
- What foods should I eat to hit my macros and lose weight the fastest? How to plan your meals to fit your macros
- How do I get started tracking macros? Read our guide to start IIFYM today
If you want answers to these questions, here’s where to start:
Download Macro Max – Our Macro Tracking App
Be well,
Anthony Collova
Founder, IIFYM.com
