If It Fits Your Macros (eat it)

IIFYM stands for If It Fits Your Macros

The word 'Macro' is short for Macro Nutrient, of which there are four: Protein, Carbohydrates, Fat & Fiber. IIFYM deals mostly with the first three of the macros, with less of an emphasis on fiber. IIFYM speaks specifically to fat loss from a caloric stand point and is purely a means to improve body composition. IIFYM does not address health concerns of the heart, brain or other organs and does not put an emphasis on so called 'healthy eating'. Regardless if you like to eat pizza, or boiled chicken breasts, IIFYM teaches us that if you eat less total calories than your body requires (while getting adequate protein, carbs and fat based on the needs of your own body) you will lose weight at a stead and predictable rate. IIFYM makes fat loss easy. All you have to do is stay within your daily macros and the fat will start melting off!

IIFYM was haphazardly invented by a few competitive bodybuilders that grew tired of eating bland and boring food when dieting for a bodybuilding contest. The traditional bodybuilders diet is very plain, very tasteless and usually reduced to a handful of simple food options:

Chicken & turkey breast
White fish (grilled)
Steamed vegetables
Brown rice
Rice cakes
Oats or plain oatmeal
Protein Shakes
Egg whites

These are commonly referred to as 'clean' foods, and there are tons of them out there, all, equally flavorless and mundane. I am sure you can see how eating these things day after day, week after week for months on end would get extremely boring. Sure, the traditional bodybuilders diet has been getting athletes shredded for years, but it has also been making bodybuilders miserable for just as long. Thanks God for IIFYM!!

The athletes that came up with the IIFYM method of dieting did so for that exact reason. They were tired of eating the same tasteless things when dieting for a show.
They were sick of cutting out the food they enjoyed; the so called 'dirty foods'.
An example of dirty foods, would be exactly what you are thinking right now. All the foods we love to eat:
Fast food
Fried chicken
Pizza
French fries
Cheesecake
Candy
Cookies
Buffalo Wings

All the good stuff that would surely wreck your diet if you even so much as thought about eating them. (or would they?!?!)