Obesity in menopausal women occurs because of the systemic effects of loss of ovarian function, resulting in increased
body weight and oxidative stress.
Caloric restriction (CR) is essential for
weight loss, since it provides benefits associated with metabolic normalization resulting from the action of
sirtuins. The aim of this work was to evaluate the physiological effects of
weight cycling in ovariectomized females. Females aged 2 mo (n = 8/group) were submitted to simulated surgery,
ovariectomy (OVX group), and
ovariectomy with weight fluctuation (WF group). In the WF group,
weight cycling was performed two times, using 21 days of ad libitum commercial feed and 21 days of
caloric restriction with 40% of the feed consumed by the OVX group. After 17 wk, the animals were evaluated experimentally. Weight fluctuations reduced
triacylglycerol and the adipose tissue index of the WF animals, while increasing the expression of
antioxidant proteins. In addition to causing fluctuations in the physiological parameters, the
weight cycling led to increases of adipocyte number and serum
fatty acids. These effects were reflected in increased expression of the
sirtuin (
SIRT) 1 and SIRT4
proteins, as well as
protein complexes of the mitochondrial electron transport chain, especially in the liver and adipose tissues. The
weight-cycling results suggested that mitochondrial and nuclear
sirtuins were active in cellular signaling for the control of lipid metabolism, oxidative phosphorylation, and redox status.
Weight cycling was able to restore the health characteristics of lean animals.