IIFYM: What's it all about?

Posted by Ellie Hearn in Health / Nutrition

Estimated reading time: 3mins

Is this Bro Science?

In terms of research, there are numerous studies showing some correlation between flexible dieting and dieting success. One study found that when comparing a flexible diet and a strict diet, those following a restrictive approach to dieting were more likely to have a higher BMI, reduced feelings of self-control and more psychological stress related to weight and food intake.

IIFYM is praised for its ability to encourage consistency and prevent yo-yo diets. This is because people can fall off the bandwagon when they’re restricted to particular foods like chicken and broccoli. So by having the ability to change it up can help some people stay on track.

Nutritional sciences Ph.D, bodybuilder and coach Dr. Layne Norton believes that IIFYM provides sustainability unlike other ‘fad diets’ that often cause people to yo-yo.

“The point of flexible dieting is consistency. Diets fail because people can’t be consistent. They try to diet forever and inevitably gain all of the weight back.”

Dr. Norton hasn’t eaten a ‘cheat meal‘ in 7 years! He says if he craves pizza, he will fit some into his macros and move on.

So how can you adopt IIFYM and get your body into shape if you’re constantly eating pizza? Well unfortunately, you can’t always have your cake and eat it too.

Most successful IIFYM athletes eat clean foods, they’re just more lenient with fitting in the foods they crave every now and then. So as much as you might want to eat donuts all day, common sense says it’s not a staple for the best physiques.


Donuts and pizza vs. sweet potato and rice

Although eating donuts or pizza as carbohydrate sources sounds delicious, it’s important to note that IIFYM has some pitfalls.

You can work your favourite foods into your diet when you crave them, but they should always be a treat. This is to ensure you don’t miss out on important micronutrients (vitamins and minerals) and so that your body still gets complete proteins, complex carbohydrates and essential fats.

Tracking food via an app (like MyFitnessPal) is very useful for IIFYM diets as you can see which micronutrients you need more or less of. This is particularly good for tracking saturated fats, sugar and sodium.

So, is IIFYM for me?

IIFYM is an approach that works for some and not for others. It allows more control and freedom to indulge every now and then, but like any diet it also requires self control, hard work and motivation combined with exercise.

Depending on your goals and lifestyle various other diets, including ketogenic and clean eating, may work better for you. Ultimately, the best way to know is to try!

Stay tuned for future blogs on other diets and lifestyle choices.


  1. Timko, C. and Perone, J., 2005. Rigid and flexible control of eating behavior in a college population. Eating Behaviors, [online] 6(2), pp.119-125. Available at: Rigid and flexible control of eating behavior in a college population.
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