Here's a bit of the article:
"Some researchers say that a calorie-restriction diet triggers a survival mechanism in animals with short life spans, such as rodents, that allows them to outlive food shortages. However, it's unclear whether people may benefit from a calorie-restriction diet the same way. Some researchers estimate that a long-term calorie restriction diet may only increase a person's life expectancy by 4 to 17 percent.
Researchers haven't identified a precise calorie limit for a calorie-restriction diet. It's even difficult to make general recommendations about calorie thresholds, due to variables such as body composition, genetics, age and daily energy expenditure. Generally, however, a calorie-restriction diet may call for 20 to 30 percent fewer calories than usual. If you're interested in a calorie-restriction diet for anti-aging, talk to your doctor.
The calorie-restriction diet isn't safe for everyone — particularly older adults and people who are lean. Side effects of the calorie-restriction diet might include:
* Menstrual irregularities
* Hormonal changes
* Reduced bone density
* Loss of muscle mass
If you're following a calorie-restriction diet, you can offset some losses in bone density and muscle mass through regular physical activity, such as walking or jogging, and by making sure you get enough calcium and vitamin D.
Excessive calorie restriction can cause:
* Anemia
* Dizziness
* Depression
* Irritability
* Lethargy
* Swelling in your legs and feet"
This is me again:
First off, it sounds like this has only been tried on rodents and if you read the first paragraph I copied/pasted, you will see that it says it's unclear if this will even help people.
Secondly, they haven't even determined the number of calories to eat/restrict.
Third, why would you even consider risking the possible bad effects from doing this? They could end up wiping out any benefit you might get.
Fourth -- it specifically says that if you are interested in this, talk to your doctor.
We aren't doctors on this forum and having been somewhat anorexic as a young woman, I know first hand what extreme calorie restriction can do. I, personally, would never encourage anyone to do this.
http://www.mayoclinic.com/health/calorie-restriction-diet/MY00578
Why do you want to do a "long term calorie restriction? What benefit are you hoping to gain? Please explain how this would be a good thing.
Your body needs a certain amount of calories just to stay alive and if you drop below that, you will do much more harm than good.