rats not liking lab block

[user 19729]

I have 3 male rats and fed them a shunamite diet before, but one rat stayed skinny and anoother one got obese.
since 2 weeks i switched them to science selective blocks. (i'm from the netherlands and cannot buy oxbow or Harlan over here).
the first 5 days i only provided the blocks and no other food. they almost starved themself, so i started adding fresh veggies and some grainmix in the morning.

the oldest male now maintains his weight, one has lost about 10gr since the start 2 weeks ago, and the other one (the obese rat) lost 60gr in two weeks. they are both still loosing some weight, despite adding the veggies and mix.
the obese rat has lost a lot of weight but has a healthy weight now. he shouldn't loose more though....
i halve seen all 3 of them eat the blocks, only the obese rat eats very little of it.
the blocks are provided in the evening and night. in the morning i feed some veggies and after that a scoop of grainmix, this is all finished within an hour.
i feed new blocks again in the evening etc.
(i think i feed about 50% block/30% veggies and 20% grainmix)

 

[Kye]

The thing about rat blocks is that they tend to be very filling, I'd keep an eye on them but they just might not feel the need to eat a ton !

 

[user 19729]

it might be better for them, not overeating it, do you think that rats can starve themself by not eating enough?

 

[Kye]

It's possible but unlikely, if you notice they get lethargic or start getting dangerously thin then you may have to intervene but otherwise I'd just watch