Is fasting good or bad? Got interested after seeing benefits of intermediate fasting in retreats from noon (more energy more time)  - but started to read about benefits of longer fasts now   (24 hours - 28 days) 

But there is the whole middle way thing to consider - did buddha talk  against fasting ? or just against fasting to suffer on purpose thinking that would liberate you ?    

If i do it for health benefits it might be ok - right ?     

maybe it does have benifits that can help the practice (more energy more time etc).
The object of Buddhist fasting is to eliminate the old habits. (ie:hunger)
This should be practiced in a middle way. That is why monks are required to not to eat after midday.
If you extend the fasting more than that it becomes the self-mortification. which was rejected by Buddha.