HealthDay News — Calorie restriction (CR) over two years is associated with considerable weight loss, and with lower than expected energy expenditure (EE) relative to the weight loss, according to a study published online in Cell Metabolism.
Leanne M. Redman, Ph.D., from the Biochemical Research Center in Baton Rouge, La., and colleagues examined whether EE and its endocrine mediators are reduced with a CR diet over two years in a study involving 34 CR and 10 control non-obese adults.
The researchers found that about 15 percent CR was achieved over two years, resulting in 8.7 kg average weight loss; controls gained 1.8 kg.
EE measured over 24 hours or during sleep in the CR group was about 80 to 120 kcal/day lower than expected on the basis of weight loss, indicating a sustained metabolic adaptation. Significantly reduced thyroid axis activity and production of reactive oxygen species (F2-isoprostane) accompanied this adaptation.
“Findings from this two-year CR trial in healthy, non-obese humans provide new evidence of persistent metabolic slowing accompanied by reduced oxidative stress, which supports the rate of living and oxidative damage theories of mammalian aging,” the authors write.