You'd have to define 'pretty constant', but yes my insulin requirements for food are pretty stable but maybe 2u a day less on a training/swimming day, eat more then inject more, 20 years back I was using a lot more insulin to eat a lot more but was over 10kg heavier lean, if I had 4 extra units I'd hypo without eating extra carbs, so for me eating more increases my weight, but not in visceral fat.
I knew a non d guy who did bodybuilding competitions, he pestered me for insulin to use to help weight gain, along with far too many imho anabolic chemicals.
Now here's a thing, he didn't want the insulin for weight gain per se, but to maintain his body in an anabolic state post work out, as in with a positive nitrogen balance, which allows more protein to be synthesised and muscle growth to happen, whereas normally after a work out we become catabolic, and have a negative nitrogen balance which draws nitrogen from the muscles preventing growth, at least that's long story short, which is why moving more and eating less is always a good start for weight loss....