What is Flexible Dieting? Here’s How to Get Started

My experience with many diets led me to believe some foods are good for you and some foods are bad for you. The way you lost weight was determined by the foods you cut out of your diet and so on.

Chicken + Rice = Good. Ice Cream + Lollies = Bad.

“Eat clean” used to be my mantra. Until now.

Flexible dieting has been recently gaining momentum as a revolutionary new way of eating.

Flexible Dieting Google Search

Flexible Dieting Google Search

What is Flexible Dieting?

Flexible Dieting (also known as If It Fits Your Macros) is simply the counting of macronutrients (protein, carbohydrate and fat) to achieve a body composition goal.

In a nutshell, Flexible Dieting IIFYM can be summed up in three steps:

Step 1: Calculate your TDEE (total daily energy expenditure) based on your current weight and exercise.

Step 2: Calculate your macros in ratios that help you reach your desired goal.

Step 3: Track your food intake and try to meet your TDEE and macro limits each day.

Counting Macros
Macronutrients or Macros make up the majority of our diets. There are three main macros: Protein, Fat, and Carbohydrate. One gram of each macro has a calorie value.

  • 1 Gram of Protein = 4 Calories
  • 1 Gram of Carbohydrate = 4 Calories
  • 1 Gram of Fat = 9 Calories

Rather than typical calorie counting (e.g. Eating 2000 cals a day) Flexible Dieters track macronutrients (e.g. Eating 150g Protein, 80g Fat, 170g Carbohydrate = 2000 cals) which more effectively influences body composition rather than just weight loss or gain.

Flexible Dieting follows the belief that there are no miracle weight loss foods. No good or bad foods, just macro ratios.

For example:

McGrilled Chicken Burger

McGrilled Chicken Burger

McGrilled Chicken Burger:

  • 25g Protein
  • 33g Carbohydrate
  • 15g Fat


Brown Rice and Tuna 

  • 25g Protein
  • 33g Carbohydrate
  • 15g Fat

Both are the same macros and so both will achieve the same results in your body composition.

When food enters your stomach your body isn’t thinking “Healthy or unhealthy?” it is simply breaking down the food and processing the macronutrients.

Essentially, to change your body you can eat whatever you want so long as you hit your macro goals. This was demonstrated in the twinkie diet.

ebooksPlease see our flexible dieting solution. It contains everything you need to know and do to be successful with tracking and counting macros. Plus, meal plans, recipes, helpful hints and much more.
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To maintain and improve overall health, although not necessary to change your body, I’d recommended tracking your fiber intake as well. This will ensure that you are getting enough micronutrients as well.

The American Heart Association recommends eating 14g of fiber per 1,000 calories consumed.


What Are the Benefits?

As I’ve mention before I’ve experimented with a wide range of different diets. All of them have their merits but Flexible Dieting is by far my favorite (and one I continue to follow today).

Below I’ll give three reasons why:

1. Effective

The most important tool in weight loss is understanding that a calorie deficit is necessary for losing weight.

Although quality is still important, quantity is the greater determining factor in weight loss or gain. If you’re not in a calorie deficit you can eat all the “good foods” you want and go nowhere.

By tracking everything that enters your mouth you stop the guess-work and take control over how & when you reach your goals. Tracking, whether it’s your macros or calories, is hands down the most effective way to change your body. (Read about how Jim lost 88 pounds by doing this)

2. Flexible (Duh)

Flexible dieting is just that: Flexible.

By focusing on your macronutrient intake rather than eating certain foods you can still achieve your goals while enjoying life with everyone else. You can have your cake and eat it too! 

One of the challenges I’ve always found around dieting was the awkward social element. There’s only so many dinners you can bring Tupperware containers full of rice and chicken to without feeling like a complete a-hole. Research shows that a more flexible approach leads to less anxiety, and more successful weight management.

By allowing yourself flexibility you can join in on meals with families and friends, so long as you keep track of what you’re eating.

3. Sustainable


photo credit: JD Hancock via photopin cc

For years my cycle would look the same. I’d set myself a super restrictive way of eating and then “Diet, Diet, Diet, Binge…Diet, Diet, Diet, Binge”.

I had such an unhealthy view of eating and because of that I never really stuck to anything long enough to get results.

I didn’t realize that food is not just physical it’s also psychological.

Flexible Dieting is the first thing that I’ve been stick to consistently over a long period of time. From my research and experience, it seems to kill the “Diet, Binge” cycle many of us have found ourselves on.

Because you can eat whatever you want (in moderation) it’s more mentally & emotionally sustainable. 

How to Get Started

1. Calculate your Macros

If you are a do-it-yourself kind of person and want to understand the process, then check our new Flexible Dieting Solution or read the guide to setting your macros.

2. Count Your Macros

This way of eating is all about tracking and measuring your macro intake.

I personally use the MyFitnessPal app (iOS or Android) as it has the worlds largest nutritional database. It’s also available across all platforms.

See our IIFYM/MyFitnessPal Tutorial to set everything up.

3. Buy a Food Scale

A lot of nutritional information is available on food packaging, however, a scale will ensure you accurately track what you eat.

Without overstating it, I feel flexible dieting has completely revolutionized what and how I eat. I love having the ability to eat with family and friends, I’m seeing great results and I can see myself doing this for years to come.

MORE: See how Ted dropped to 8.6 percent body fat by using flexible dieting.

Need More Help?


    Scientific Reference:

  • Smith, C. F., Williamson, D. A., Bray, G. A., & Ryan, D. H. (1999). Flexible vs. Rigid dieting strategies: relationship with adverse behavioral outcomes. Appetite, 32(3), 295-305. URL


  • Mayra

    Hi, I’m 31, mom of two. Lift weights 3 to 4 times a week. Have been not over 108-110lb for so long and I felt skinny I ate a lot food but then I realized it wasn’t enough to gain . So decided to eat a more caloric dense and I’m finally at 116lb my goal is 120lb. My only concern is that I seem to be putting on fat on my belly and inner tights. That’s is the reason I want to try IIFYM but first want to know if teaches you how to put on weight!

    • http://www.caffeineinformer.com/ Ted

      Hi Mayra and great job on your gains, Yes IIFYM is perfect for gaining lean muscle mass and it’s all about finding your macro sweet spot. This can take a bit of adjusting but what you are striving for is enough calories to gain muscle but not too much that you also gain fat.

    • Marco Sanchez

      Mayra, i am sure you look beautiful just the way you are.

  • Dptodd

    a lot of people at my crossfit gym eat by macros, but I’m a little unsure of this. I’ve always been taught that counting calories is not the best approach because the body does not process food the same way even if the calorie count is the same. my main concern is dropping body fat and trying to lose 10% BF. On this type of plan would I have to follow the same calorie deficit that other calorie counting plans follow? ie- lose 2 lbs per week= 7000 deficit?

    • http://www.caffeineinformer.com/ Ted

      Hi There, No, it’s more individualized than that. You would calculate your personal TDEE for maintaining your current weight, then you would create a calorie deficit of 20% per day. This would vary person to person. I think what you’ve been taught isn’t really accurate. The majority of research shows that being aware of calories and reducing calories is a trusted method of weight loss and flexible dieting teaches you to do so in a healthy way that is designed to keep the metabolism from slowing down as happens with many really low-calorie diets. Please check out my book for a comprehensive step by step approach to getting started. https://healthyeater.com/ebook

    • Edward

      Hi dptodd
      You can flex and your macros it is a lot more effective than calorie counting .

    • Tyler Rambo

      Dptodd you are absolutely right that calories from one food compared to another are utilized much differently. Nutrition textbooks love to dock vegetables of all kinds because they don’t ‘absorb’ as well as animal products. What they don’t highlight is the fact that with all that extra fiber, water and phytochemicals they have, sends a slice of their calorie pie to the toilet instead of your waistline all the while reducing risk of chronic disease. So you could realistically eat your recommended TDEE for maintaining your current weight, while actually LOSING weight if you are eating from whole food sources!

  • Edward

    Checkout macroflex from ultimate food essentials they are really doing great job with flex dieting and Marco calculations

  • Kelsey

    Hi! My TDEE is 1225 cals per day. You say you recommend subtracting 500 to lose weight?? With the 1225 cals my macro goals are 119g carbs, protein 111g, and 34g fat per day…If I subtract 500 from 1225, what are my macro goals then?? Do they stay the same?? Please help?!

  • Tara Hancock

    Hi there! I’m stuck right now and could really use some help. I’ve used your calculator (which I think is one of the best ones out there) and my TDEE is 1326. I’m recovering from a difficult back injury at the moment and am not able to work out except for some of my physical therapy stuff. I’d consider myself sedentary even with doing PT strengthening 3x week – definitely not breaking that 200 calorie benchmark for “light activity” group. Since I’m not working out, I chose the lower protein option: 100 protein, 149 carb, and 37 fat. I do really good about getting close to these numbers, but I’ve been stuck for about 2-3 weeks now. I’m just not sure what I’m doing wrong. Any advice?

    • http://www.caffeineinformer.com/ Ted

      Hi Tara, sorry to hear about your injury. I would switch up the protein and perhaps eat a little more on your PT days. Your body is in the process of healing so resources are needed for this, especially protein.

      • Tara Hancock

        Thanks for your reply! I’ll give that a shot.

  • Sarah Ginsberg

    Hi! My macros are 1610 cal, 200g carbs, 90grams, protein, and 50 grams fat. At what point in my macro calculations during the day do I have the flexibility to incorporate the “unhealthy” type foods?

    • http://www.caffeineinformer.com/ Ted

      Hi Sarah, at any time as long as the food fits your remaining macros.

      • Sarah Ginsberg

        Sorry, I’m just a little confused. What are considered “remaining macros?” Meaning, how many grams of healthy, nutritious food should I be consuming in each macro category before I decide to designate the rest as “remaining”?

        • http://www.caffeineinformer.com/ Ted

          It’s totally up to you, hence the word “flexible” but I recommend that people choose healthy foods 85% of the time. But if you have a day where only 50% of your macros are from whole food sources, it’s not going to stop your progress. Just don’t make flexible dieting rigid like other plans or it ruins the freedom this type of eating offers.

          • Sarah Ginsberg

            Awesome, thanks so much!

  • Bob

    “Flexible Dieters would track macronutrients (e.g. Eating 150g Protein, 80g Fat, 170g Carbohydrate = 2000 cals) which more effectively influences body composition rather than just weight loss or gain.”

    You are incorrect. Macronutrient composition does not effect body composition. http://www.ncbi.nlm.nih.gov/pubmed/22258266

    • http://www.caffeineinformer.com/ Ted

      Hi Bob, the study you pointed out was looking at the goal of fat loss and focused on diet alone and you’re right there wasn’t much difference. This study showed that more protein did preserve lean body mass during weight loss. http://jn.nutrition.org/content/133/2/411.full Also, adjusting macros added with the correct exercise can change body composition. i.e. increasing protein coupled with a weight training program helps increase muscle mass.

  • Rafael B.

    Hello, very well explained, thank you!

    What happen if I dont respect the macros but I still reach my calorie goal?

    For example, what if I need to eat 1600 calories to lose weight, but I eat less grams of carbs and more grams of fat, but I still reach the same goal??


    • http://www.caffeineinformer.com/ Ted

      Hi Rafael, macro levels are more for fine tuning your results. i.e. more carbs help fuel your workouts and help you progress, adequate protein helps maintain and build muscle etc.

  • lopez2017

    Hi, so if my initial calorie intake given to me by the calculator tool was 1,687 (221C, 95P, 47F) and I’m readjusting it to lose weight (1,345 calories), wouldn’t/shouldn’t my macros be adjusted, too? Or do they stay the same?

  • Mallison Brincat

    great article!!! Do vegetables count and you have to keep a record as well as the other food or eating vegetables is unlimited? thank you

    • http://www.caffeineinformer.com/ Ted

      Hi Mallison, Yes they do, there are no “free foods” with flexible dieting. Veggies have macros, so we include them.

  • lopez2017

    I’d like to post this questions again: Hi, so if my initial calorie intake given to me by the calculator tool was 1,687 (221C, 95P, 47F) and I’m readjusting it to lose weight (1,345 calories), wouldn’t/shouldn’t my macros be adjusted, too? Or do they stay the same?

    • http://www.caffeineinformer.com/ Ted

      Hi There, I’m a bit confused by your question. The calculator readjusts everything for you, macros and all, when you select “lose”.

      • lopez2017


        Yes, it did readjust it for me! However, I’m referring to the line in the article “How to Calculate Your Macros” that reads: If you want to lose weight I recommend dropping your overall calories by no more than 20% to start with – So in the example, this would take the guys calories from 3,250 to 2,600 for weight loss.

        That is where I got 1,345 calories (1,687×0.2). I just wasn’t sure if I’m supposed to adjust my macros with this new calorie intake.

        • http://www.caffeineinformer.com/ Ted

          When you click “lose” on the calculator it deducts the 20% automatically fro your maintenance TDEE.

  • JennyB

    Hi there, I am just coming off a 6week 10 lb weight loss based on restricted calories. I am ready to ease back into a higher calorie intake. Do I need to do it slowly to protect my body composition or can I go from 1200 calories to your calculator suggestion (about 2200) fairly quickly. I’m still looking to lean out a bit.

    • http://www.caffeineinformer.com/ Ted

      Hi Jenny, Great job on your weight loss. It can be a good idea to ease into a higher calorie plan if you’ve been pretty restrictive for a time period. Perhaps add 100 more calories every other day and see how your body responds.

  • Autumn

    I’m a little confused because if I choose the McDonald’s over the rice and tuna the McDonald’s has very high sodium which will make me bloat a lot. My daily sodium intake is 2,300. One meal would take up half of that easily. Maybe my macros are just off? I eat 1,200 calories a day. Protein is 135. Carbs are 60 and fat is 47g.

    • http://www.caffeineinformer.com/ Ted

      Hi Autumn, That example was just comparing calories and macros of the two. Of course, the overall nutrition (micronutrients) of each is very different. It does seem like your macros are pretty low especially if you exercise daily.

  • ShemenSasson

    The link at the end of this section is broken; can you tell me where I might read about this topic?:

    “I had such an unhealthy view of eating and because of that I never really stuck to anything long enough to get results.

    I didn’t realize that food is not just physical it’s also psychological.”


    • JamesF

      The article was a great piece by Layne Norton. Unfortunately the site seems to have removed that article (and a number of others). We have linked to another good article about the psychological cues to eat.

      • ShemenSasson


  • http://ironandgrit.com Hozzy

    Nice write-up. Thanks for sharing. I have been using IIFYM a.k.a. Flexible Dieting for a while now and have lost 10 pounds of (mostly) fat! I wrote an article about the subject. Maybe there are different ‘cues’ in my article that will resonate with people! Hope this helps: http://ironandgrit.com/2015/10/24/if-it-fits-your-macros-iifym-flexible-dieting

  • Veronica

    Just want to know how do I know the food composition, I know I need 160 g carbs 100 protein and 39 g fat, but how do I know how much of those each food contains? Does the book help in that sense? Also I change my training everyday I might be doing 3 times a week running and twice some kind of workout with light weights, does my intake change? Many thanks.

    • http://www.caffeineinformer.com/ Ted

      Hi Veronica, It looks like you’ve bought the book. Thank you! 🙂 Reach out to me in the members only forum if you have additional questions after reading. And we can also talk about your goal of gaining muscle as well. No need to buy both.

  • Veronica

    Sorry also I want both to loose weight and to gain muscle shall I buy both books?

  • Crystal

    I just purchased the personal coaching and filled out he questionnaire. I never received a confirmation that it was completed successfully. Should I fill it out again? Thanks!

    • http://www.caffeineinformer.com/ Ted

      Hi Crystal, Sorry I don’t believe there is a confirmation for that. I got it and just completed your plan and sent everything to you just now. If you don’t get the email, please let me know. I look forward to coaching you!

  • Gina Visser

    Does flexible dieting only work for weight lifters & cross fitters? I’m not allowed to lift heavy, but I do have a bit of weight to lose so I’ve started a cardio and resistance training regimen, and would like to know if iifmm works for ‘normal’ active ppl as well as bodybuilder types. Can’t find anything on the topic.

    • http://www.caffeineinformer.com/ Ted

      Hi Gina, It sure does and even works if someone does no exercise. Please see the weight loss edition of my book. It will guide you through the process step-by-step. https://healthyeater.com/ebook

  • hcornetto

    I’m curious if, when counting carbs, it is done similar to how low carb diets do where the “net carbs” are calculated, or if this plan does not differentiate between carbs and net carbs.

    • http://www.caffeineinformer.com/ Ted

      Hi there, In a technical sense only net carbs are the carbs that are supplying energy so they should be counted, But, this is difficult because many nutritional labels and trackers don’t take this into consideration. It’s easier to just count total carbs and then use your fiber amount as a bit of a buffer. If you go over your total carbs by 15 grams, but have eaten 25 grams of fiber, you’re still in good shape.