What contributes the most to how many calories you burn each day?
a) your basal metabolic rate (click here to calculate yours)
b) the “thermogenic” effect of the food you eat (i.e. celery is negative calories, vegetables take a lot of effort to digest, sugar goes through immediately and doesn’t take much effort)
c) exercise
d) non-exercise movement throughout the day

Ok, which one?
And which is next, etc.?
If you said your BMR (basal metabolic rate) is the highest, you would be right – that is the energy required for core bodily functions and it accounts for about 60% of all energy expenditure. Then, the thermogenic effect of food has a small effect – only about 10% of your energy expenditure is affected. Then movement takes up the remaining 30% of energy expenditure. But which movement – exercise or non-exercise movement?

A study in this issue of the Mayo Clinic’s Endocrinology Update[i] describes that non-exercise movement can have a much larger effect than exercise, and be almost the entire remaining 30%!

“NEAT” Effect on Your Body

Non-exercise movement is referred to as “NEAT” – Non-Exercise Activity Thermogenesis. It turns out that for two adults “of similar size, daily energy expenditure varies by as much as 2,000 calories per day.” 2,000 calories per day difference!!! And since the BMR and effect of food is approximately the same in two adults of the same size, then that entire 2,000 calories difference can be due exclusively to movement!

But, Dr. James Levine of the Mayo Clinic says that most of the world does not exercise and he cautions, “Even for the minority of people who do exercise, for most of them, exercise accounts for an energy expenditure of 100 calories per day. Thus, NEAT explains why an active person can expend 2,000 calories per day more than an inactive person of the same size.”

Lean People Naturally Build More Movement into Their Lives

16 lean volunteers were taken and overfed by 1,000 calories per day. Some of them naturally increased the amount of activity they were doing – they naturally increased their NEAT in response to the calorie increase. Those who most increased their NEAT did not gain fat, even with overfeeding. On the other hand, Dr. Levine wanted to study how obese people move during non-exercise.

Obese People Tend Not to Move as Much
Dr. Levine and his colleagues put microsensors into the tightfitting clothes of obese and lean people. These microsensors measured movement every half-second for ten days. The result? Obese people are seated on average 2.5 hours per day more than lean people!

So, do get up to take breaks at work!
And do park your car further from the entrance to the mall so that you have to walk.
And maybe even start fidgeting.
And definitely get up from your seat to get more drinking water regularly.
And use the stairs whenever you have the chance!

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[i] The “NEAT Defect” in Human Obesity: The Role of Nonexercise Activity Thermogenesis. Endocrinology Update. Mayo Clinic. 2(1). 2007

Full article as it appears in the American Heart Association is here.
Non-Exercise Activity Thermogenesis: The Crouching Tiger Hidden Dragon of Societal Weight Gain by James A. Levine; Mark W. Vander Weg; James O. Hill; Robert C. Klesges


3 Comments

  1. Posted Thursday April 26, 2007 at 3:54 am | Permalink

    A scientific excuse to fidget! Jay :)

  2. Posted Thursday April 26, 2007 at 4:11 pm | Permalink

    Grim,

    Totally, this is an excuse to fidget! Here is a 2005 NYT article about a similar study by the same scientists, The Fit Tend to Fidget. :)

  3. Posted Monday May 7, 2007 at 11:32 pm | Permalink

    1725???!!!???

    I would burn 1725 calories if all I did was stay in bed all day???!!! Crazy! That is wild! I never knew that!

    So, when I go to the gym and get on the bike for 45 min, or lift weights for an hour, I burn about 400-450 calories.

    That makes 2175 I need to take in, plus another 10% (242) of food digestion makes roughly 2420 calories per day I need. VERY interesting.

    So, technically, if I wanted to lose weight, the main thing for me to do would be to MOVE a lot more. Walk more, exercise more, etc. Taking in less food, especially calorie-rich foods, is a second step.

    Since I’m a 160 lb 33 year old male, I want to gain muscle tone and size. So, I’d have to take in more calories, but not much more, move less, and certainly lift more weights.

    Sounds about right. :) Thanks!