Simplify the following text for a Grade 8 native English-speaking person.
Original: In developing and developed countries who operate either commercial or industrial agriculture , food waste can occur at most stages of the food industry and in significant amounts . In subsistence agriculture , the amounts of food waste are unknown but are likely to be insignificant by comparison , due to the limited stages at which waste can occur , and given that food is grown for projected need as opposed to a global marketplace demand .
Simplified: In subsistence agriculture , the amounts of food waste are unknown .