People take protein powder for lots of different reasons. Generally, though, the main idea is to develop a lean physique with plenty of powerful muscle and as little fat as possible. But, sometimes concerns arise when people look at the nutrition information on the tub of their favorite protein powder. After all, there is a pretty significant amount of calories packed into even the highest-quality protein supplements. So, is it possible for protein powder to work against your weight loss efforts? Can you get fat from too much protein powder? Macronutrients 101 To fully answer this question, it's important that we first explain the basic nutritional principles at work here. Although your body requires lots of different vitamins, minerals and other substances, there are not used for fuel and are only needed in small quantities. Carbohydrates, fats and proteins, though, are the major players. Called macronutrients, these are the nutrients that your body relies on most heavily for fuel, energy and raw building materials. But each class of macronutrient is used a little differently. Generally speaking, carbohydrates and fats are your main sources of energy. Carbs, though, can be broken down and metabolized faster so they tend to be used most often – especially during burst of short, intense activity. Because fats contain about double the amount of calories but are a little more challenging to use, they're generally stored and used as a back-up. Protein, however, is structurally much more complicated. In fact, about 30 percent of the calories contained in each gram of protein are used up just in processing that same chunk of protein. Using protein for fuel, then, just isn't a smart investment. Plus, proteins are made up of amino acids, commonly called the “building blocks of life.” Those amino acids are needed for building and repairing every tissue in your body. They're also used to create several important hormones. So, if those amino acids were burned for fuel, other biological functions could suffer. The Big Question So, will chugging protein powder make you fat? It's possible. After all, any excess calories could be stored as body fat – regardless of which macronutrient it was when it entered your body. Protein, however, is your body's last choice for fuel. It has much more important things to do. In order for protein powder to add any noticeable fat to your frame, then, you would need to need much more than you actually need. Read More: 7 Essentials to Look For In Your Whey Protein Powder Three Great-Tasting Whey Protein Recipes The Best Protein Powder for Clean Eating