As mentioned,Kaytee isn't a good brand.It's essentially junk,and if I'm being honest their food is a waste of money.They might have some nice toys at times,but their food is just not worth buying
For Syrians,Harry/Hazel Hamster as mentioned would be an excellent food.You could also feed a mixed diet using several brands of food,but these must be high quality brands as well.Higgins Sunburst would be great when mixed with a higher protein food,either Mazuri rat and mouse lab blocks(difficult to find though)or Carefresh hamster food(much easier to find,and generally cheaper).I would not recommend feeding most other US hamster foods though,as they just aren't anywhere near as good.
For a dwarf hamster,the only good option would be Burgess dwarf food ordered off of Viovet.It doesn't have added sugar or fruit which is very good for a diabetic prone species(Vitakraft and other brands do have some form of added sugar in them,even if only fruit),and the pieces are also just right for tiny dwarf ham mouths!
With the Higgins/Carefresh mix,you give 1 tablespoon of Carefresh and 1/2 tablespoon of Higgins.Then,add a few pieces of freeze dried chicken(Pure Bites,for example,but this must be plain chicken,nothing added).You can also add a pinch of flax seed occasionally,but you definitely need the chicken as Carefresh and Higgins combined falls just a tiny bit short of being high enough in protein.With the added chicken though it is fine,and definitely a great option considering it can be very affordable as well as lasting quite a while for a Syrian!