They do not have the luxury of sending a lot of freshly prepared foods from the earth to the moon everyday.
How much food do you think we need to live comfortably?
10 pounds a day of meats and cheese?
It largely depends on what & how much your body needs:
*Energy/carbohydrates (fuel) for work,
*Protein(building material),
* others: minerals, vitamins, oil etc
A hardworking adult needs lots of foods especially those rich in natural energy and couple of protein, vitamins, minerals, oil rich foods.
People who do little to no work need little food. If they eat more than they need the foods will be passed out from the rear end or/and stored in the body as fat.
* Note that Work equals (=) Solving problems. The more problems you solve the more food you need. And working isn't necessarily physical activities even though it is very important. Maybe excersing should compensate for lack of that. And exercising is also working, though abit selfish because it solves problem for self