The If It Fits Your Macros weight loss diet is simple and easy to follow, and lets you eat whatever you want, event “junk food” while still helping you to lose weight. It’s a great diet, but it is not without issues. If you’re focused purely on hitting the same macro and calorie targets every day you might find that your performance suffers when you train.

Eating for Performance Maximizing Your Macros

Your body needs protein for muscle growth and repair, healthy fats for hormone production and energy, and carbohydrates as a readily available energy source. While it is possible to use fat as your primary energy source, many performance athletes find that they perform better when “carb fueled”.

The first thing you should understand is that your weight will change regardless of the macronutrients you take in, as long as your calorie intake is correct. Calories are the key metric for weight loss.

Your satiety, well-being and body composition, however, will be determined by the macronutrients that you eat.

If you focus on “eating clean” without paying attention to macros, and hit your calorie goals, you will lose weight but you may feel deprived. If you hit your calorie intake at lunch time with a fast food meal then you will be hungry and cranky by evening.

Macros give you balance, and on the surface, it looks like there is a case for eating different macros on different days, depending on the type of exercise that you do and how hard you train.

macro calculator for weight loss

Macros for Weight Training

If you do a lot of weight training, you need extra protein for recovery. If you don’t have that protein and you are eating at a calorie deficit then you run the risk of losing muscle mass. The weight on the scale might move, but your overall body composition may end up less than ideal.

Even if you don’t end up losing too much muscle you might struggle to recover between workouts. You won’t gain strength as quickly as you would with adequate protein intake, and the risk of injury is higher.

Adding a little extra post-workout protein to your intake on days that you lift could be beneficial.


Macros for Cardio

Here’s where things get tricky. Some people adapt to a high-fat diet easily and perform equally well whether they’re following a high-fat diet, a high protein diet, or one with more carbs. Other people find that they need carbs to do cardio.

This is very much an individual thing. It’s also something that could be worked around through nutrient timing. If you really struggle to get through that jiu-jitsu class or aerobics session without some carbs, have a piece of fruit a while before the session so that it’s digested and hitting your bloodstream at the right time.

You Don’t Need to Adjust Your Macros Daily (But You Can if You Want)

If you really want to micromanage your food intake then you can change your diet based on your day to day activity. However, many people find this stressful and find that it makes it more difficult to stick to a long term way of eating.

In addition, if your goal is weight loss and you start changing your calorie goal and macro targets on a day to day basis you could hamper your recovery. If you eat more to “fuel that long run” then less the next day, you’re depriving your body of nutrients it could use to repair your body after the intense exercise.

Remember that your body is not a car that needs fueled every X number of miles. It is a more complex machine with its own built-in energy stores. Some micro-nutrients are water-soluble and should be replenished regularly.

Others, however, are stored in your body. Nutrients such as Vitamin B12 can take years to deplete.

You will not keel over if you skip a meal. Your body won’t “turn carbolic and destroy all your gains” because you had less protein than you needed one day. What matters is long term habits. If over the course of the week, you are getting the right balance of protein, carbohydrates, and fats to support your activity level then you will be OK.

Finding the Right Balance

The right balance will differ depending on your habits. If you are a triathlete, you probably do want to have a diet that is rich in carbs. Up to 55-60% is not unheard of for people who put in a lot of miles running or cycling.

People who are aiming to gain muscle will want to eat more protein. People who are less active will likely aim for a balanced diet such as 40/30/30% across the macronutrients.

These are broad, example figures. The real ideal figure is individual and is based on your age, gender, current weight and target weight, body composition and level of activity, as well as the types of activities that you do.

If you get those figures right when averaged out over the course of the week then you will find that you don’t need to fuss with different meal plans and with “over-eating” some days and “under-eating” on others.

getting the most from the iifym macro diet

Don’t Sweat the Small Stuff

One common mistake that dieters make is throwing away the whole diet because they made one mistake. There is no need to do that. It’s not a waste to eat a steak “at a time when your muscles don’t need it”. Your workout won’t be ruined because you skipped that pre-workout.

Your body is the culmination of a series of small choices, and even partly right choices will still get you towards your goals. Focus on getting to the gym on the days you aimed for.

Use the IIFYM calculator to get a clear idea of your targets averaged out over time and stick to those. Build that as a habit long-term, then consider refining that if you’re a competitive athlete who needs to peak for a specific day.

For most of us, however, this is a lifetime effort.