Using a kettle instead of pot should make you less hungry. In all seriousness I've used both. I like the flexibility of using a pot as a kettle you can only really boil water and not cook with it. Although the pouring ability of a kettle is nice. In other words you can probably make out with using a pot without a kettle but not the opposite. Comes down to a weight and space saving issue for me.
I have a teapot I bought from REI mail order years ago. I would bring my self-designed meals that required boiling water, a sierra cup, a heat resistant medium seized bowl, and an old metal tablespoon. It all worked very well for me for several day trips from early spring through late fall.
I carried the Trangie aluminum tea kettle for a few years in leiu of a pot when I was doing nothing but freeze dried food (Rehydrate in the bag)
- but if you were rehydrating anything else, you would at least still need to carry a large mug and/or bowl.
I finally settled on a dentede 2.4 cup Ti pot thatI got in the bargain basement at Cabella's. It was lighter still, than the kettle but allowed more functionality.