Steady weight loss is the key to long-term success.
Calories in versus calories out is about as simple as it gets. Weight control -- loss and gain -- is based on the number of calories you consume and burn every day. You take in calories with the food and drink you consume. You burn calories through exercise, but also in the normal course of living every day. Knowing the average number of calories you burn in a day can help you maintain your current weight and make adjustments for weight loss or weight gain.
The average number of calories needed on a daily basis varies from person to person. This is based on a number of factors specific to you: your weight, your height, your age, your physical activity level and your gender. A simple equation, called the Estimated Energy Requirements equation, can determine the amount of calories you need on average, based on your specific parameters.
There are two EER equations: one for men and one for women. Choose the correct equation before entering your variables. For men 19 years and older, the equation is as follows: EER = 662 - (9.53 x Age) + Physical Activity x (15.91 x Weight) + (539.6 x Height. For women 19 years and older, the equation is EER = 354 - (6.91 x Age) + Physical Activity x (9.36 x Weight) + (726 x Height). For this equation, you need to calculate your height in meters -- divide total inches by 39.37 -- and your weight in kilograms -- divide your weight in pounds by 2.2. The physical activity factor for men is 1.0 for sedentary; 1.11 for low activity; 1.25 for active and 1.48 for very active. For women, it's 1.0 for sedentary; 1.12 for low activity; 1.27 for active and 1.45 for very active.
Doing the Math
If you aren't used to working with long equations, you'll need to understand what is called order of operations. This states that you should work from the inside, that is, do everything in the parentheses first, followed by everything in the brackets. When working from the inside out, do any multiplication before addition and subtraction. If you've done the math correctly, you should get an answer between 1,200 and 5,000 calories.
Once you've determined the average number of calories you consume in a day, you can calculate the calorie deficit or surplus you need to lose or gain weight. To lose weight, you need to take in fewer calories than your EER and/or increase your physical activity level. It takes a deficit of 3,500 calories to lose one pound of weight. Safe weight loss is about 1 to 2 pounds per week.
If you are looking to gain weight, increase the amount of calories consumed or decrease your physical activity level. When doing so, make wise food choices and activity changes. For example, eat a variety of foods from all the major food groups and avoid foods that contain high amounts of saturated and trans-fats. Don't reduce exercise levels to less than 30 minutes of moderate activity five days of the week to decrease your chances of chronic diseases related to inactivity.