I feed the NLS to my four @home Bettas (my office Betta eats Omega One) and what I have learned is that it really depends on the individual fish. I have one young male who I think will probably always be on the smaller side (he was a "baby Betta" from Petco and I have heard that many of those don't reach full size) but may still be growing, so he gets probably four or five NLS in the morning, an evening treat of frozen food (we alternate between frozen mysis shrimp, frozen brine shrimp, frozen blood worms, or frozen beef heart) plus another one or two NLS before bed most nights. The three girls (one VT and two CTs) are all different. My largest girl is one of the CTs, Aurora, and she actually requires the least amount of food of all of them, or she gets porky. She gets one or two NLS in the am, a very small amount of frozen food at night, and never gets a before-bed snack. The other two girls get about three or four NLS in the am, some sort of frozen food in the evening, and then the little VT, Bettina, gets one NLS before bed - she's really tiny, but she must burn it all off because she is a complete maniac ... she NEVER stops racing around ... and is just over, under, into, and through everything in her tank.
I don't fast my @home Bettas, or have not until recently - I just left for the weekend for the first time since I've had them so I was a little nervous, but they did fine. I may start fasting them one day a week - my office Betta has always fasted two days a week on the weekends and done fine.