I'm no health expert, so take what I say with a pinch of (low-sodium) salt. However, it does seem to me that the amount of calories you burn standing up for a few hours is not going to make much difference to your health.
You're correct, unless you use a treadmill desk or you're one of those people who can't sit still and bounce around while they type (like me!). Just because you're standing doesn't mean you have to be a statue.
There's something else to consider though: lipoprotein lipase. It's generated in large amounts by your leg muscles and is used to break down fat into energy. Sitting causes a steady decrease in lipoprotein lipase production in your legs. The longer you sit, the less lipase you produce.
At that point, losing weight becomes extremely difficult and you start craving sugar for energy. There's a theory of weight management that people who don't gain body fat manage it because, throughout any given day, your insulin levels go up and down, you store a little fat then you burn a little fat. The ability of your body to switch back and forth between burning sugar and fat is called metabolic flexibility. Sitting destroys that flexibility.
Lots of swaying helps keep everything loose as well as keeping focused on using the leg muscles to support yourself instead of relaxing and letting the cartilage do all the work which is the only real concern I've come across for a standing desk.
There's something else to consider though: lipoprotein lipase. It's generated in large amounts by your leg muscles and is used to break down fat into energy. Sitting causes a steady decrease in lipoprotein lipase production in your legs. The longer you sit, the less lipase you produce.
At that point, losing weight becomes extremely difficult and you start craving sugar for energy. There's a theory of weight management that people who don't gain body fat manage it because, throughout any given day, your insulin levels go up and down, you store a little fat then you burn a little fat. The ability of your body to switch back and forth between burning sugar and fat is called metabolic flexibility. Sitting destroys that flexibility.