If you ever had the feeling that thin people seem to be moving a lot, and heavier people less so, you were right. Fidgeting does, in fact, burn extra calories that otherwise might be stored as fat.
Fidgeting Burns Calories
Fidgeting might hold the secret to why some people gain weight and others don't, all while eating the same amount of calories. The key factor in predicting weight gain is how many calories are burned over the course of the day, and every bit of movement counts. The exact number of calories burnt varies, depending on your style of fidgeting. Pacing burns more calories than pen tapping.
Whether you burn calories without exercise or not depends on whether your body can switch on non-exercise activity thermogenesis, or NEAT. NEAT switches on when people move in any way whatsoever, from bicycling to doing laundry -- even when chewing gum. While tapping your foot or pen might only burn a fraction of a calorie, over a day's time those calories add up.
Every Little Bit Counts
The New England Journal of Medicine reported on a Laval University study that measured the calories burned by 100 pairs of identical twins. The participants who were deliberately fed an extra 1,000 calories per day gained weight in direct proportion to the amount of NEAT that was activated. In real life, if you weigh 155 pounds and sit up and read for 30 minutes, you'll burn 42 calories, vs. 28 calories while watching TV and 23 calories while sleeping.