It can be empowering to examine the math of weight loss to better understand what happens each week on your weight loss journey.
Calories are a unit of energy. As you may know, when you burn more calories than you eat, your body breaks down stored body fat to meet the excess calorie demands.
Your body burns calories in three primary ways:
1. Resting metabolism rate (RMR)
Most of your calorie expenditure is to keep your brain, organs, and body functioning. RMR can be reduced when you cut your calories too quickly or don’t exercise to preserve muscle mass. Most people burn 1200-2000 calories each day, even while resting in bed!
2. Daily activity
When you get out bed, your body needs fuel to move, and the good news is that all activity burns calories. The more movement you have in the day, such as walking to the mailbox, taking the stairs, and doing the dishes, add up to about 300-600 calories per day. Those of us that work from a desk or computer burn far few calories each day than those who are on their feet doing physical labor.
Getting at least 150 minutes a week of physical activity in any form - walking, swimming, biking, strength training, and group exercise classes - makes a big difference toward the additional calories that are burned. When you increase your intensity, such as walking at a pace considered “moderate” activity, you will burn more calories than strolling along. That said, a long stroll can burn a lot of calories. Calories burned by those engaging in 20-60 minutes of activity usually burns about 200-600 calories per exercise.
To improve your weight loss results, eat a calorie level that at least matches your RMR. If you are exercising a lot, you’ll need to bump up your calories, otherwise you’ll feel hungry or unusually tired and experience slower weight loss.
Here’s a calorie breakdown example for a typical participant of the Diabetes Prevention Program:
RMR: 1300 calories burned
Daily Activity: 300-600 calories burned
Exercise: 200-600 calories burned
Total Calories Burned in a Day: 1800 - 2500 calories
On the lower side, this participant burns 1800 calories and consumes 1500 – this is a 300-calorie deficit – which should lead to just over ½ pound of weight loss per week if she/he did this every day. (NOTE: One pound = 3,500 calories so a deficit of 500 calories per day x 7 days = 3,500 calories).
On the higher side, this participant burns 2,500 calories each day and would have a 1000-calorie deficit which should lead to a 2 pound per week weight loss.
Keeping a log of your food and physical activity can be a great way to understand why you are losing, gaining or maintaining your weight. It can help you figure out if you should get more physical activity, reduce some calories, or do a combination of both. Whichever way you choose to adjust your calorie balance, it is helpful to be in-the-know about WHY your body does what it does!