http://www.ajcn.org/cgi/content/abstract/72/6/1451
Energy expenditure of nonexercise activity1,2,3,4
James A Levine, Sara J Schleusner and Michael D Jensen
1 From the Endocrine Research Unit, Mayo Clinic and Mayo Foundation,
Rochester, MN.
Background: We found recently that changes in nonexercise activity
thermogenesis (NEAT) mediate resistance to weight gain with overfeeding
in sedentary adults. A potentially important, yet seldom investigated,
component of NEAT is the energy expenditure of fidgeting-like
activities.
Objective: Our goal was to measure changes in energy expenditure with
fidgeting-like activities.
Design: Energy expenditure was measured in 24 subjects (17 women and 7
men; ± SD body weight: 76 ± 21 kg) while recumbent at rest, sitting
motionless, standing motionless, partaking of self-selected
fidgeting-like movements while seated and while standing, and walking
on a treadmill at 1.6, 3.2, and 4.8 km/h (1, 2, and 3 mph).
Measurements were performed by using a high-precision, indirect
calorimeter connected to the subject via a transparent, lightweight
facemask that enabled almost unrestricted movement.
Results: Compared with metabolic rate in the supine position (5.4 ±
1.5 kJ/min), energy expenditure increased while sitting motionless by 4
± 6%, while fidgeting while seated by 54 ± 29% (P < 0.0001), while
standing motionless by 13 ± 8% (P < 0.0001), while fidgeting while
standing by 94 ± 38% (P < 0.0001), while walking at 1.6 km/h by 154 ±
38% (P < 0.0001), while walking at 3.2 km/h by 202 ± 45% (P < 0.0001),
and while walking at 4.8 km/h by 292 ± 81% (P < 0.0001). There was a
significant, positive correlation between changes in energy expenditure
and body weight for fidgeting-like activities while standing (r = 0.43,
P = 0.02) but not while seated.
Conclusions: There is marked variance between subjects in the energy
expenditure associated with self-selected fidgeting-like activities.
The thermogenic potential of fidgeting-like and low-grade activities is
sufficiently great to substantively contribute to energy balance.
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How does one factor "thermogenic potential of fidgeting-like and
low-grade activities" when trying to determine amounts of calories to
consume when trying to lose weight when they can vary by person by up
to +- 38% or +-45% or even +-81% depending on type of fidgeting?
Them are pretty wide variances for a supposedly simple calories-in vs
calories-out concept.
TC