Role of Nonexercise Activity Thermogenesis in Resistance to Fat Gain in Humans
James A. Levine,
Norman L. Eberhardt,
Michael D. Jensen
*
Humans show considerable interindividual variation in
susceptibility to weight gain in response to overeating. The
physiological basis of this variation was investigated by measuring
changes in energy storage and expenditure in 16 nonobese volunteers who were fed 1000 kilocalories per day in excess of weight-maintenance requirements for 8 weeks. Two-thirds of the increases in total daily
energy expenditure was due to increased nonexercise activity thermogenesis (NEAT), which is associated with fidgeting,
maintenance of posture, and other physical activities of daily life.
Changes in NEAT accounted for the 10-fold differences in fat storage
that occurred and directly predicted resistance to fat gain with
overfeeding (correlation coefficient = 0.77, probability < 0.001). These results suggest that as humans overeat, activation
of NEAT dissipates excess energy to preserve leanness and that failure
to activate NEAT may result in ready fat gain.
J. A. Levine and M. D. Jensen, Department of Medicine,
Endocrine Research Unit, Mayo Clinic and Mayo Foundation, 200 First
Street Southwest, Rochester, MN 55905, USA. N. L. Eberhardt,
Departments of Medicine and of Biochemistry and Molecular Biology,
Endocrine Research Unit, Mayo Clinic and Mayo Foundation, 200 First
Street Southwest, Rochester, MN 55905, USA.
*
To whom correspondence should be addressed. E-mail:
jensen.michael{at}mayo.edu
