There have been several questions coming to me from athletes trying to figure out their macros. Let’s take a second to better what the macros are, and understand why we recommend what we do.
The 3 main macronutrients in our diets are carbohydrates, proteins, and fats. They are called ‘macro’ nutrients because of their large size relative to other nutrients such as vitamins and minerals which are consequently called micronutrients. Macronutrients are the only source of calories in our diet, and we should think of calorie equating to energy – only calories can actually give our bodies energy.
This different macronutrients have different functions in the body. There is more in depth information in the Vault on the Nutrition page under Step 3 – definitely check that page out for more information. Briefly, however, as they pertain to exercise, the major functions of the macronutrients are as follows: carbohydrates are our immediate energy source and preferred fuel for working muscle – they are the only fuel working muscles can use at high intensities. Protein is essential for protein (muscle) synthesis and repairing the muscle after we break it down from working out. Fats are an energy source at low intensities and at rest. Again, this is a very basic overview.
Different approaches have different sets of recommendations. A common approach that we are seeing is basing macro recommendations on a percentage of calories in the diet; for example, consuming 50% of calories from carbohydrates, 20% from protein, and 30% from fat. For most individuals this can be fine. However, if we really look at the sports science behind macronutrients we see that what is most important in terms of optimally fueling our bodies is ensuring we are consuming adequate grams of carbohydrate and protein per kilogram (kg) of body weight. So, theoretically, someone could be consuming 50% of their calories from carbohydrates, but still be consuming inadequate amounts if they are only consuming 1,200 calories (50% of 1,200 kcals is only 150 grams of carbohydrates). Thus the importance of absolute grams per kg as a baseline for recommendations.
Now, many athletes see their recommendations and commonly find that their current intake is higher in protein than what is recommended (& maybe fat), and lower in carbohydrate. This is especially common in paleo-ish (I just love that term…) diets and other current trends. Again, for many individuals this still may be fine – if we have healthy functioning kidneys it is likely not causing any kidney damage or other adverse health effects. I just challenge you to consider increasing your carbohydrate intake slightly, and lowering your protein intake slightly, and see if you notice a difference.
For some individuals this is quite scary – it goes against what they have always heard about the importance of high protein intakes. Let me reassure you that the recommendations from the Vault/nutrition calculator actually are high protein intakes – just not as high as what some may be used to. Keep in mind our bodies can only metabolize 30 grams of protein at any given time. So, all the extra protein does not go towards muscle synthesis. Conversely, eating more carbs (gasp!) may seem scary since our culture has become somewhat carbaphobic. I don’t advise eating lots of cookies and candy to increase your carbohydrate intake; rather, focus on whole grains, legumes, fruits, vegetables, and milk/yogurt. These are excellent, nutrient dense sources of carbohydrates. If your calories stay the same you will not get fat (I promise), and you may find your energy levels are improved.
At the very least, I recommend giving it a try. Worst case scenario you are no better off (but you won’t be worse off); the alternative is that you might feel and/or perform better. And of course, let me know how it goes!