Anyone who wants to lose weight has probably heard the saying, "You need to burn more calories than you eat." Here’s how to get an idea of how many calories you burn in a day.
What Is a Calorie?
You can think of calories as fuel for your body. Like a car, your body needs to burn fuel to work. Your body's calorie needs are like the gas tank in your car. If you let the tank get empty, your car won't drive. If you don't give your body enough energy, it can't work properly.
A big difference, though, is that your car's gas tank has limited room for fuel. You can't overfill it. But you can easily put more calories in your body than you need on a given day. When that happens, the excess energy is stored in fat cells so that you can use it later. Doing that too often leads to weight gain.
What Is Metabolism?
When your body processes food into energy, it's called metabolizing. Your metabolism is the system for turning food into energy that you can use to keep your body working. Your body uses energy all the time, even when you're asleep. You are constantly metabolizing calories. The energy is used to fuel the general functions in your body.
Here are some key things to know about the process:
Basal metabolic rate. This is the number of calories you need to keep all your basic bodily functions going. This includes breathing, your heartbeat, your nervous system, and all the rest of the automatic things your body does every day.
Thermogenesis. This is a technical term for the energy it takes to convert food into usable energy. Eating, digesting, transporting, and storing food inside your body takes up to 10% of the energy from the food you eat.
Physical activity. Moving your body demands more energy. This is in addition to what you're using to keep all the essential functions going. Every action, no matter how large or small, takes some number of calories. A simple task like unloading a dishwasher uses a small number of calories. Strenuous activities use more calories.
How Many Calories Am I Using?
Every person is slightly different. You can make a rough estimate of your non-exercise calorie needs based on your age, weight, and sex.
For example, a 50-year-old man who’s 5'10" tall and weighs 165 pounds may burn about 1,650 calories a day. A 50-year-old woman who’s 5' 6" and 135 pounds may burn about 1,400 calories per day. Younger people tend to burn more calories than older people.
Exercise burns more. Adding physical activity to your day ups the number of calories your body burns. Different kinds of exercise take different amounts of energy. A 160-pound person doing 1 hour of exercise might use up the following number of calories for these activities:
- Elliptical machine: 365 calories
- Golf (carrying clubs): 314 calories
- Running (5 mph): 606 calories
- Walking (3.5 mph): 314 calories
- Bicycling (under 10mph): 292 calories
- Hiking: 435 calories
The most effective way to burn more calories is by adding physical activity into your routine. Your basal metabolic rate remains reasonably steady, though it does get slower as you age. Researchers have found that you can speed it up a little bit by building more muscle. That’s because muscle requires more energy than fat. More muscle tissue means you burn more calories overall.
Health condition effects. Some health problems lower basal metabolic rate, such as thyroid disorder, polycystic ovarian syndrome, or Cushing Syndrome. These are not very common, though. If you’re concerned that you might have any of these issues, you can ask your doctor to do tests to find out what’s going on with you.
Most experts suggest that 30 minutes a day of activity is good for overall health and for burning extra calories. Talk to your doctor if you have questions about adding exercise into your daily routine -- they can help you get started.