Calorie restriction (CR) is a dietary intervention with potential benefits for health-span improvement and lifespan extension, David DiSalvo writes on Forbes.
A recent study shows a connection between CR, fat loss and reduced oxidative damage to our cells. Additionally, there is a connection to a slowdown in metabolism while asleep.
CR is more than just slightly cutting calories as you might with any number of diet plans.
CR means shaving off between 15-18% of total recommended daily calories. It extends maximum lifespan in most species.
15-18% is a significant drop, almost equivalent to a plate of scrambled eggs.
Many animal studies have linked CR with health benefits all the way up to an extended lifespan.
The “why” of this isn’t clear, although many suspect a connection between those benefits and a change in metabolism.
In the study, 53 (34 CR and 19 control) non-obese adults, were assigned a CR or normal diet to follow for two years.
The study results show that 15% CR was achieved for young, healthy individuals over 2 years, resulting in an average 8.7 kg weight loss, whereas controls gained 1.8 kg.
Most of the weight loss was in the form of body fat.
The most noticeable result came from blood tests showing that the CR group experienced a 20% drop in oxidative cell stress.
That’s key because oxidative stress leads to cell damage. Cell damage in turn plays a role in the development of cancers and other disorders.
The factor connecting these results seems to be a reduction in resting metabolic rate.
Over the first year of the study, it appears that the metabolic rates of those in the CR group changed.
By year two their nighttime metabolism dropped by around 10%.
The researchers describe this change over the two-year period as “sustained metabolic adaptation.”
This metabolic adaptation was accompanied by significantly reduced thyroid axis activity and reactive oxygen species production
This is the first study to show this effect in humans.
The researchers were careful to point out that they didn’t designate a specific diet for the participants, so these results can’t be linked with dietary recommendations.
“Future research on CR for healthy aging would benefit from considering the diet quality of individuals who have successfully defied the aging process,” the researchers wrote.
While these results are interesting, CR isn’t the right choice for everyone and anyone considering it should discuss all the factors with their doctor before beginning.