The needs and tastes vary from man to man. Every requirement, if it is met properly at the proper time, has its own worth. In this way what is a luxury for one may be a necessity for another and vice versa.
If you are thirsty and need a drink, a delicious dish of meat may be superfluous to you. A drug of poison may be an antidote to another poison, but it may be fatal to whom who does not need it.
To extend this logic further one can say that one man’s food is another man’s poison. It is true not only for an individual but also for a nation.
Thus a country with surplus manpower is advised to prefer small scale industries and cottage industries while a country lacking manpower may be benefited by adopting large scale industries or heavy industries.
Machines may be the ‘meat’ for an underpopulated country, but they are poison to an overpopulated country.
Thus, the proverb indicates that what is conducive to one’s ability and interest may be detrimental to another in different contexts.