Is IIFYM a fad diet?

Unless you have been under a rock, you are hard pressed to find a person in the fitness community who has not heard of the concept of “If It Fits Your Macros” or IIFYM for short. There are many aspects of this diet that are seductive to both athletes and the general population.

The concept is simple: Once a range of protein, carbohydrate, and fat have been decided, it does not matter what foods you consume. The only thing that matters is that you meet your numbers for the given day.

Pro:

This can be a dream come true for a person who just can’t live without the proverbial poptart.

If somebody is allotted 250 carbohydrates and 75 grams of fat in a day and they want to blow 75 grams of carbs and 14 grams of fat on a couple poptarts, it is totally cool. If you are a person who has a healthy relationship with food (having the capacity for portion control) then this is an excellent option for people who need to get their itches scratched without going “off” their diet.

Con:

It can however be easily seen how this diet can really throw a person off course in the (micro)nutrition department. Although it is totally possible to lose weight eating foods exclusively like the one listed above, you are not nearly as likely to take in enough essential nutrients. Although you may be fed, you just aren’t nourished the way you should be. If this is the case then your performance at work/school/gym will likely suffer as a result. As most of us know, long term nutritional deficiencies increase the likelihood of (preventable) disease and malnutrition associated illnesses.

Takeaway:

It is unlikely that somebody would truly bring themselves into a pathological state using IIFYM. However, I feel that eating whole unprocessed foods is the way to go, as they are far more (micro)nutrient dense. Somebody who is looking to optimize their fat loss and performance will have better luck sticking to their “bodybuilding friendly” foods.

Not only will stabilizing your blood glucose and insulin secretion help to keep you sated, but it is a widely corroborated that keeping insulin response to food limited will decrease fat storage in the mid section and increase fat loss in the  midsection. Below is one of many scientific trials conducted that correlate GI of carbohydrate intake with fat loss in the mid section on an isocaloric diet. This means that people eat the same number of calories/macros but the food choices were different. The group who ate the “healthy” foods, lost more fat and retained more muscle mass than that group that consumed the higher GI foods.

Goss AM, Goree LL, Ellis AC, et al. Effects of diet macronutrient composition on body composition and fat distribution during weight maintenance and weight loss. Obesity (Silver Spring). 2013;21(6):1139-42.

If somebody is serious about their nutrition and tracks every macro, then including a treat here and there is a perfectly acceptable way to maintain your physique (and sanity) without going off course in the long run. Just keep in mind that half of a cup of uncooked oatmeal will take you a heck of a lot further than a decent sized of soda.