Today, we lose weight. The University of Houston's
College of Engineering presents this series about
the machines that make our civilization run, and
the people whose ingenuity created them.
Just back from a delicious
lunch at the University Center -- meat loaf,
potatoes, and a cookie. I can usually get away with
eating like that; my weight stays pretty stable.
Now I'm back in my office reading a Science
magazine article. As I read, I swing my leg, flex
random muscles, rock in my chair. In short, I
fidget.
The article is about the role of NonExercise
Activity Thermogenesis. The three authors from the
Mayo Clinic give that the acronym N-E-A-T,
NEAT. They've done an interesting
experiment. They found sixteen volunteers whose
weight was normal -- both men and women in their
twenties and thirties. Then, for eight weeks, they
fed them a thousand calories beyond what they
needed each day.
During this time they studied three forms of energy
expenditure. One was basal metabolism, the normal
generation of heat by a body at rest. The second
form was postprandial heat generation. That's
energy we burn in digesting, absorbing, and storing
food. Neither form varied in any consistent way
with weight gain.
The third means for burning energy is, of course,
exercise. In this case, the doctors carefully
monitored conscious exercise and made sure it
stayed at a constant low level. But (and here the
fun begins) we exercise in two ways: consciously
and unconsciously.
So these doctors measured the overall heat
generation from physical activity, then subtracted
off that part of it which was conscious exercise.
What remained was the NonExercise Activity
Thermogenesis, or NEAT, for each person.
Some people in the experiment gained almost no
weight, and some gained as much as ten pounds. That
weight-gain was independent of basal metabolism and
postprandial heat generation. But it correlated
almost perfectly with NonExercise Activity
Thermogenesis. The greater the NEAT, the less the
weight gain.
To a born fidgeter, that seems like wonderfully
good news. I sit here in my chair noticing my
micro-motions for the first time. I catch myself
flexing my legs, bouncing my feet heel-to-toe,
shifting my position in the chair -- and savoring
my excellent lunch of meat loaf with
cheese-sautéed potatoes. My body is dealing
subconsciously with that meal.
This study is a small one. I suppose it could be
subject to statistical noise. Yet it's convincing
because the result is so unsurprising. Fancy
studies often tell us what we knew was true all
along. Did we really need a Surgeon General to tell
us that cigarettes are just a legalized drug or
that a lifetime in the coal mines gave miners
emphysema?
But this study does point to the possibility of
behavioral changes. Perhaps there are ways to evoke
the processes of subconscious exercise. You may not
want to become a fidgeter, but the study does
suggest that we can find ways to exercise -- even
while we're doing our ubiquitous couch-potato desk
jobs.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
