This
study investigated the influence of dietary supplementation with L-carnitine on
metabolic rate, fatty acid oxidation, weight loss and lean body mass (LBM) in
overweight cats undergoing rapid weight reduction. Thirty-two healthy, neutered,
colony-housed cats were fed an energy-dense diet unrestricted for six months,
then randomly assigned to four groups and fed a weight-reduction diet supplemented
with 0 (control), 50, 100 or 150 μg of carnitine/g of diet. Following weight
loss, cats were allowed unrestricted feeding of the energy-dense diet to
investigate weight gain after test diet cessation.
Median
weekly weight loss in all groups was 1.3%, with no difference among groups in
overall or cumulative percentage weight loss. During restricted feeding, the
resting energy expenditure-to-LBM ratio was significantly higher in cats that
received L-carnitine than in those that ate the control diet. Respiratory
quotient was significantly lower in cats that received L-carnitine on day 42,
compared with pre-diet, and in all cats that received L-carnitine compared with
the control group.
A
significant increase in palmitate flux rate in cats fed the diet with 150 μg of
carnitine/g relative to the control group on day 42 corresponded to
significantly increased stoichiometric fat oxidation in the L-carnitine group
(over 62% vs. 14% for the control group). Weight gain (as high as 28%) was
evident within 35 days after unrestricted feeding was reintroduced.
Dietary
L-carnitine supplementation appeared to have a metabolic effect in overweight
cats undergoing rapid weight loss that facilitated fatty acid oxidation.
Source: S.A. Center et al., 2012. Influence of dietary
supplementation with L-carnitine on metabolic rate, fatty acid oxidation, body
condition and weight loss in overweight cats. AJVR 73: 1002-1015. doi: 10.2460/ajvr.73.7.1002