To maintain a healthy lifestyle, it's important to keep your weight at a healthy level for your age, height and gender. When you don't control your weight, you put your body at risk for a wide range of health problems ranging from diabetes to even certain forms of cancer. Maintaining a healthy weight relies on a constant balance between the amount of calories you take in through diet and the amount of calories you burn through activities, including exercise.
Calorie Deficit vs. Calorie Surplus
In keeping track of calories for weight loss, the goal is to create a calorie deficit. A calorie deficit occurs when you burn more calories through activity and basic body function than you do through your meals during the day. When you take in more calories than you burn, you create a calorie surplus, which can result in weight gain. When trying to maintain your weight, keep the amount of calories you take in and burn approximately equal to each other.
To calculate your calorie goal for either weight loss or weight maintenance, subtract the amount of calories you burn with your basal metabolic rate from your diet calories first. Your basal metabolic rate, or BMR, is the amount of calories your body burns at rest with activities like your heart beat or breathing. To calculate your BMR, use the following equations --
Women BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age)
Men BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age)
Once you have subtracted your BMR from the food calories you've consumed, subtract the calories you burn from activities like exercise. The number of calories you burn varies widely based on the intensity of activity, length of exercise and other factors such as your current weight. Online tools like Livestrong.com's MyPlate can help to more accurately estimate the number of calories you burn performing common exercises and activities.
Once you subtract your BMR and calories burned from activity from your calorie intake, you will end up with either a positive or negative number. A negative number denotes a calorie deficit, which encourages your body to use body fat for energy, resulting in weight loss. A positive number is a calorie surplus. With a surplus, your body stores excess calories as fat, resulting in weight gain. If the number is relatively close to zero, you will maintain your current weight.