What Is A Calorie Deficit? If you've spent any time researching weight loss, you've heard the term "calorie deficit" thrown around like it's the answer to everything. And in many ways, it is the foundation but very few people actually understand what it means, how to do it safely, or what happens when it's done wrong. Let's break it down properly. The Basics: Calories In vs. Calories Out As human beings, we burn calories every single day just to stay alive this is our fuel. T