Calorie Intake- Calorie Usage = Calorie Deficit
If Calorie Intake is lower than Calorie Usage
Calorie Intake is from (1) Meals + (2) Drinks + (3) Snacks
Calorie Use is (1) Basal Metabolic Rate ( BMR) + (2) Activity like house work or gardening+ (3) Exercise like running, jogging, weight training etc.
You will not lose weight doing exercise if you do not achieve Calorie Deficit. To do that controlling Calorie Intake is crucial