It's not just calories though, for example, the spaghetti carbonara I just had from M&S, which wasn't exactly huge, had 79% of the RDA for saturated fat. I saw that after bringing it home and was
The actual problem is with transfats and sugars, not saturated fats. I'm not sure why all this buzz about fat still goes on, but it's nonsense. It's like those "low fat meals" are often full of sugar to replace the flavour that's been lost by reducing the fat. They'll have to change this at some point because excess sugar will make you pile on weight rather than saturated fat.
The thing that bugs me about that is that in a number of labels they'll say the serving size is 250ml or whatever and then proceed to state what 500ml is as well, if someone can't roughly work out what double is without having it spelled out for them then I'm slightly worried for them.
Personally, I'd prefer (though I don't really check calories much) that they just put the contents of the jar on and that's it. It's all well and good having a label about half the contents of the jar, but it's only true if you measure out that portion accurately (pedantic, I know) so is just as meaningless really. At least if they list the whole jar/bottle you can make a rough guess about the values of it.
I can eat a pint of ice cream and I'm no tubbo.
Better of watching calories than portion sizes IMHO.
To be honest, they're both somewhat meaningless. It's best watching the type of food you make and eat. Don't buy ready meals, learn to cook from scratch as much as you can, for example when I have pasta with a tomato sauce, or spaghetti bolognaise, I don't use any sauces from a jar. I'll use tinned tomatoes, or tomato puree, various vegetables, spices, herbs and in the case of bolognaise, the meat juices add flavour.
That's far better than counting calories and watching portion sizes because it's nowhere near as simple as that. The whole RDA thing is only a loose baseline anyway, and I've found that it's angled towards people who are just about skin and bones, who don't do any physical activity at all.

(there's no way I could handle 2000 calories a day).