>studies suggest that malnutrition might confer a longer lifespan.
There are some data suggesting that inadequate supply of this or that nutrient reduces certain aging mechanisms and leads to longer lifespans in a laboratory setting. However, outside of a laboratory setting these nutrient deficiencies can affect the body's ability to fight infections and heal injuries, which on average cancels out any benefits.
More generally, trying to increase lifespan by adjusting the diet seems to me like trying to fix a car by playing with the buttons and knobs on the dashboard. You might obtain a small improvement, but you're not really going to get anywhere unless you open the hood.
There are some data suggesting that inadequate supply of this or that nutrient reduces certain aging mechanisms and leads to longer lifespans in a laboratory setting. However, outside of a laboratory setting these nutrient deficiencies can affect the body's ability to fight infections and heal injuries, which on average cancels out any benefits.
More generally, trying to increase lifespan by adjusting the diet seems to me like trying to fix a car by playing with the buttons and knobs on the dashboard. You might obtain a small improvement, but you're not really going to get anywhere unless you open the hood.