Rick, a top-level Fortune 100 executive, had absolutely no problems staying sharp, focused, and energized during his hectic ten-hour workday. When he left the office, he was almost giddy with anticipation about spending the evening with his family. All that changed on the drive home when his energy level crashed. By the time he got to his front door, it wasn’t just his physical energy that was waning; he was grumpy and impatient with his wife and family.
A former client of mine, Sara, told me that her hunger was uncontrollable and worried that there might be something psychologically wrong with her. After work, she picked up her son at day care, drove home, and then went into the kitchen to start dinner. As soon as she opened the pantry, though, she said she got “lost,” eating everything in sight.
Enough! I Want Food and I Want It NOW!
While the complaints of these two individuals couldn’t be more different, the cause is the same. Sara ate very little during the day, saying she wasn’t hungry for breakfast and didn’t have time for lunch. Finally, just before dinnertime, her body screamed “Enough!” and demanded the fuel it was deprived of all day, leading to the raid on the pantry.
Rick didn’t fuel himself enough during the day either, relying instead on stress and caffeine to keep him going. While stress and caffeine may feel like “energy”, they can’t fuel the body.
We sometimes forget that our bodies run on food. In fact, if you look up the word “calorie” in the dictionary, you’ll find it’s a measure of energy.
If you’re eating enough calories, but don’t feel energized, then you’re probably not eating the right type of calories, at the right time, in the right quantity.
FROM BOLERO TO BALANCED
Even if you’re not into classical music, chances are you’ve heard of Ravel’s “Bolero”. It’s a 15-minute piece that starts off quietly and then builds in a continuous crescendo to a thunderous intensity. Like Rick and Sara, that’s how many of us eat. We start off slowly with little or no breakfast and with large gaps of time between fueling. As the day continues, we start eating more food at each sitting and more often, finishing the day with our largest meal, usually close to bedtime. But, that’s not how our body needs or uses fuel.
THE BODY’S NEED FOR FUEL
The body burns calories on a steady 24/7 basis, even when we’re asleep, and it uses a lot more than you realize. All our cells and organs burn fuel nonstop…just to stay alive. And, then we need more fuel to repair our body, build muscle, and move.
Calculating the Resting Metabolic Rate
Want to know how many calories we need just to stay alive? To estimate your resting metabolic rate, use this simple one-step formula: multiply your weight by:
- 10 if you’re overweight
- 11 if you’re a normal-weight female
- 12 if you’re a normal-weight man
So, the resting metabolic rate of a 150-pound overweight woman would be 1500 calories (150 × 10). A normal-weight active 200-pound man has a resting metabolic rate of about 2400 calories (200 × 12).
Even when you want to lose weight, never eat fewer than this number of calories. Eating too few calories only lowers your metabolism, making it more difficult to continue to lose weight and keep it off.
Total Calorie Needs
Since you don’t spend all day in bed, let’s calculate how many calories you need based on a normal day of activity. To do this, multiply your resting metabolic rate (calculated above) by one of the following factors based on your overall activity level:
- 1.2 for sedentary (sit most of the day and get little physical activity)
- 1.4 for light (such as teachers who spend most of the day on their feet or those who walk leisurely 1-3 times a week)
- 1.5 for moderately active (such as food servers who walk briskly every day or those who participate in exercise 3-5 times a week)
- 1.7 for very active (such as bike messengers or those who participate in 60 minutes of intense exercise or sports nearly every day)
- 2.0 for extremely active (those who participate in hours of exercise a day)
For example, the 150-pound woman with a light activity level would require about 1500 × 1.4 or 2100 calories to maintain her weight. A 200-pound very active man would need closer to 4080 calories (2400 × 1.7).
Keep in mind that these are estimates. Two people of the same size and activity level may burn calories differently for many reasons. Those with more muscle mass burn more calories, and younger people burn more calories than older individuals. Total calorie needs may also be greater in individuals who stand more than sit or those who fidget more.
The numbers above are for weight maintenance. To lose weight you’ll want to eat fewer calories than your body needs. To start losing a pound a week you can choose to eat 500 calories per day fewer than your body needs, bump up your movement to burn an extra 500 calories, or make a 250 calorie change in both what you eat and how you move.
Realize that as you lose weight, you need fewer calories to maintain that weight so you’ll need to adjust these numbers periodically.