In reply to Andrew W:
I only use 1000 kcal meals from Expedition Foods (disclaimer: they do sponsor me) and love the range. Variety is helpful on longer trips. As someone who's 6'4" and 95kgs, any less and I'd be under fuelled, even for basic hiking trips. 800 kcal would work if you're smaller and/or female.
The standard 450-550 kcal meals are kinda pointless really! I burn anything from 4000 kcal when hiking, to 6000 kcal when on an Arctic expedition (so even fuelling 5000 per day, which is hard, will result in me losing 1kg per week).
I used to use 1000 kcal Bewell/extreme adventure foods. Their curries are nice, but the rest of the range is so so and some give very bad gas! lol. Real turmat are tasty, but very limited in the higher calorie ranges. Mountain House and adventure foods I don't like at all and wouldn't eat if you paid me, Firepot are tasty for some meals, but again limited on calories.