Overpopulation cannot cause death by starvation, because the human body has a mechanism to prevent starvation death when food is limited.
Every day, human beings starve to an early death.
How does this happen?
We know that for every person that starves to death in th eworld today, there is plenty of excess food that goes unused and uneaten, more than enough to have kept that person alive.
Any large scale starvation to death only occurs as a result of disaster causing an abrupt stoppage of resources, or as a result of human choice not to redistribute resources.
To test this, consider a thought experiment given these parameters: in a closed community of people, food is distributed to each individual according to need. To mimic a starvation scenario caused by finite supply and population but not by natural disaster, we keep the rate of food production constant and the population's desire to reproduce constant.
Given a supply of food, the people in the thought experiment will naturally multiply. As they multiply, they will eventually start using all of the food supply. As they continue to multiply, each person's share of food is decreased.
This will contnue to happen until population is high enough to mean that each full grown person will lose weight.
Eventually, each grown individual loses weight and begins losing fat stores.As the sexually mature women lose weight and fat stores, they become infertile. As a result of infertility, population ceases to rise.
Thus, the body makes reproduction impossible in the absence of excess, and therefore, rising population cannot cause death by starvation because people become infertile because they starve to death. As female athletes often prove, a woman can be infertile yet quite fit and healthy until she reaches old age.
The biological mechanism is that the human body becomes infertile before it starves to death..
The purpose of this conversation is point out that how we treat each other is more critical to our survival than any population number we attempt to adopt.