Explain Malthusian theory of population

The theory states that food production will not be able to keep up with growth in the human population, resulting in disease, famine, war, and calamity.

This because food production grows arithmetically while population grows (faster) geometrically; thus there will came  a given point in time, T, (population trap) when the population  would outstrip the means of subsistence leading to starvation, diseases, wars and death (positive checks)

Malthus suggested  that the only way  to avoid  human suffering beyond the population trap; population growth must checked by preventive negative checks such as celibacy, late marriages, family planning, moral restrain, etc.