Body Mass Index (BMI) is a calculation that shows the relationship between your weight and height. It helps assess if you have a healthy body weight. A BMI between 18.5 and 24.9 is considered healthy.
Total Daily Energy Expenditure (TDEE) is the number of calories your body needs daily to maintain your current weight. It accounts for calories burned during all activities.
To lose weight: Eat 300-500 calories less than your TDEE.
To gain weight: Eat 300-500 calories more than your TDEE.