So, TDEE, or Total Daily Energy Expenditure, is basically the total number of calories your body burns in a day. This includes the calories burned just by doing things like breathing, digesting food, and keeping your body at the right temperature (that's your BMR). It also takes into account the calories you burn when you're moving around—whether you're walking, working out, or even just doing everyday tasks.

In simple terms, TDEE tells you how many calories you need to keep your weight the same. Knowing your TDEE is super helpful because it gives you a clear idea of how many calories you should be eating to reach your goals, whether you're looking to maintain, lose, or gain weight.