800 Calorie Deficit Weight Loss. To lose weight, you MUST create a caloric deficit. The above should give a fairly accurate calorie number for reaching your goal, but to get a most accurate Total Daily Energy Expenditure (TDEE), get your body composition tested and enter your stats in the "body.
The calories out is a bit more complicated and multifaceted. Our body becomes more efficient at using energy (lowered metabolism), and therefore burns less fat. When the body experiences a calorie deficit, it starts to break down fat for energy. This is why most of us reach a weight loss plateau. A calorie deficit is the energy shortfall that results from using more energy than you absorb from food. Your ultimate goal is to figure out exactly how many calories to eat daily to lose weight without being hungry and lethargic and without sabotaging your training.
So creating and maintaining a calorie deficit is the key challenge of weight loss.
The optimal calorie deficit is large enough to stimulate steady fat loss, but not so large that you're always hungry and lethargic.
Many "miracle diets" claim incredible results through eating. The feedback provided illustrates caloric intake needed to maintain present weight as well as what would be necessary for gaining or losing weight. While the total number seems high, the weekly energy deficit can be broken down into daily deficits to make weight loss more manageable.