Best reference I've gotten is feed them their own eye each day, if they're bloated but poopin feed them half their eye each day.
If they beg for food then play with them or get a mirror so they can rawr themselves for about ten minutes. Food is unconditional love and thus not physically healthy, teach them to dance for their extra food
I use hikkari fancy guppy pellets and a cheap walmart salt shaker (little canning jar kind). I folded the seal inside and cut out a half moon a little off center so it lets food out three holes. The pellets contain no air, can sink and are 50% protein, very happy boys. With this I can be sure the boys only get a tiny amount of happy food and then feed them standard pellets for their regular diet. .. and ensure I handle the food as rarely as possible!