Need help please?

For now, I bought Iams kitten food and Iams adult food because I have 3 adult cat about 3 years of age and 1 5 months old kitten. I am planning to switch them from 9lives dry food to Orijen but there are still no stock of 7.5kg bag in my area. I just bought Iams for now since there are only limited brands of cat food in my area also. I will switch them gradually to avoid stomach upset. But regarding the Iams kitten and adult food. Should I just mix this up together or do I need to put it in a separate bowl? I am just worried that my kitten will only eat the adult food and my adult cats will just eat the kitten food? What Should I do? 

I am not an expert on this and I am sure someone better will be along soon. But I have always found that kitten food seems much more tasty than adult food! As your kitten is 5 months it would not be a disaster if it eats adult food - and vice versa, though kitten food is richer in calories. So I guess I am saying you can try to separate the two, but don't panic if it all gets mixed up.

If I buy I kilo of adult food and I kilo of kitten food and mix it together will it be fine? Or can I also just buy the kitten food and that's the one my adult cats will eat together with my kitten?

As I said, I am not an expert, but if it were me, I would not give healthy adult cats unlimited kitten food. I would mix it if you cannot separate it for hte cats and kitten.

Is your kitten a lot smaller than the adults? When we had this problem, we took a large plastic tote, turned it upside down, and cut a small hole in it on one of the ends - one the kitten could fit in but not the adult cats. We put the bowl at the far other end (so the adult cats couldn't reach the bowl with their paws by sticking their legs in ther to knock food out of the dish and thus eat it). If you can do this, it should work for at least a few months, I think.

There are a lot of dry food that are made for "all life stages". That is what I did when I had kittens and Pipsqueak together. Or you could just mix the adult Iams and the kitten Iams together if you don't want to go to a different all life stages brand. Or try Laurie's great suggestion .

Yes my kitten is a lot smaller. Great Idea thanks. I want to switch them to either Orijen or Acana  if I don't get any good results in Iams either. Thanks