Nutrition 101: Here's Why Macronutrients Matter More Than Calories

We have a confession: Sometimes our nutritionist friends use words we don’t know in conversation. While this isn’t a rare occurrence (they’re experts for a reason), there’s one word in particular that kept popping up for us: macronutrients. 

Do you know what they are? We figured some of you might not, so we enlisted registered dietitian Farah Fahad, MS, RD, to explain. First things first—we asked Fahad for the most basic definitions of both calories and macronutrients. “A calorie is how we measure energy in food. The more calorie-dense, the more energy-dense. Macronutrients are nutrients we need in macro—or big—amounts. ‘Macro’ alludes to the fact that we need it in big amounts, and it also alludes to the fact that it gives us a substantial amount of energy,” she explained.

And while there’s only one type of calorie (though not all calories are created equal—more on that later), there are three categories of macronutrients: protein, fat, and carbohydrates. Each macronutrient has a different amount of calories per gram. Protein is four calories per gram, carbohydrates are four calories per gram, and fat is nine calories per gram.

Alright, now that we know the basics of what macronutrients are, read on for Fahad’s take on why they matter, and how they might affect your health and weight.