The Calorie Budget
Your weight is a balance between the calories you eat and the calories you burn, yes? (Here’s a previous post on the topic, if you’re interested.) So let’s talk a bit more about how to put a calorie plan into action.
First, you must figure out just how many calories you need. The easiest way to do this (outside of indirect calorimetry), is to use a research-validated equation, such as the Mifflin-St. Jeor equation which accurately predicts resting energy expenditure within 10%. Here is a handy link that allows you to enter your personal information; the site then inputs that info into the Mifflin-St. Jeor equation and does all the number crunching for you. A more labor intensive approach would be to carefully measure and record your food intake for a couple weeks, using an online food journal like SparkPeople. Assuming your weight has been stable, you can use the calorie information from this food journaling to determine your average intake and–voila!–discover how many calories you need on a daily basis for weight maintenance.
The second part of this calorie reconnaissance is to create a plan that enables you to reach your goal. If you’re simply wanting a calorie plan for weight maintenance, the first step has got you covered. If you’re wanting to put on weight or shed pounds, you’ll need to do a little more math. For those wanting to lose weight, you’ll need to consume fewer calories than you need to maintain your weight. This forces the body to tap into its fat (and muscle) stores for that extra energy. For weight gain, you must have an energy surplus, so you’ll have to eat more than your body needs for weight maintenance.
Generally speaking, a pound of body weight has about 3500 calories of energy. Whether you’re seeking weight loss or gain, you can use this information to hone your calorie plan. A common rule of thumb is if you are trying to lose a pound per week, you need to create a calorie deficit of 3500 calories over 7 days. So, if you take that 3500 calories and divide it by 7 days in a week, you see that you would need to create a calorie deficit of 500 calories per day to lose that 1 pound per week. Let me be clear: This DOES NOT mean you eat a measly 500 calories per day. Rather, it means you would SUBTRACT 500 calories from how many calories you need for weight maintenance. Here’s an example:
John entered his personal info into the Mifflin-St. Jeor equation and learned that he needs 3000 calories to maintain his weight. He’s got 25 pounds to lose and would like to lose 2 pounds per week. This means he needs to create a calorie deficit of 7000 (2 x 3500) calories per week. He divides this number by 7 days in a week, which is 1000 calories per day. He subtracts the 1000 calories from the 3000 calories he needs to maintain his weight. So, to lose 2 pounds per week, he must consume 2000 calories per day.
When calculating calories for weight loss, it is important to note that there is such a thing as eating too little. Unless you are participating in a medically-supervised program, it is not recommended that you consume less than 1200 calories per day.
Suppose a person wants to gain weight. The math is practically the same, only you add calories to your maintenance calories. Here’s an example:
Susan is a distance runner and her intense schedule has recently caused her to lose too much weight. She would like to regain 10 pounds over the next few months, about 1 pound per week. She entered her personal info as well as her typical training schedule and learned she needs 2800 calories to maintain her weight. In order to gain 1 pound per week, she divides 3500 calories per week by 7, which is 500 calories per day. She adds the 500 calories to her daily intake for 3300 calories per day.
Once you’ve figured out your calorie plan, the next step is to put it to work. Next time, I’ll tell you just how to break down your calorie plan into nutrient targets that will optimize fat loss while preserving your muscle. Stay tuned!