If eating slightly less may influence biological aging, an obvious question follows:
How much less?
There is currently no scientifically established percentage of calorie reduction that is ideal for healthy aging.
Human research provides some useful clues.
In one of the most important long-term studies of calorie restriction in healthy adults, the goal was to reduce calorie intake by 25%.
In practice, participants achieved much less. Their average reduction was about 12% over two years.
Even this more moderate reduction was associated with a small slowing of one measure of the pace of biological aging.
People who achieved greater calorie restriction tended to show a larger change in this measure.
But this does not mean that everyone should reduce their calorie intake by 10%, 12% or 25%.
Individual energy needs vary considerably.
They depend on body size and composition, physical activity, age and other factors. Someone who already has an appropriate energy intake may have little reason to reduce it further.
There is also a point at which eating less can become counterproductive.
Too little energy can make it difficult to obtain enough protein and essential nutrients. It can also make maintaining muscle and physical function more difficult.
For healthy aging, more calorie restriction is therefore not automatically better.
The aim is not to reach a particular percentage.
A more useful principle is to avoid persistent excess energy intake while maintaining excellent nutritional quality and meeting the body’s individual needs.
