Not losing weight at all since getting back to Japan

Grumble, grumble...

Since getting back from St. Louis my weight loss has not been going well.
Yet I've been perfectly good on my diet.

The day I got back my weight was 88.0 kg. It dropped over the next couple of
days to 87.6 kg, one day it was down to 87.2 kg even. Then it started
creeping up again... 87.6 kg, 87.8 kg (last Friday, meaning a week-to-week
gain of 0.2 kg), then it hovered back on 88.0 again and this morning, shock!
It was 88.4 kg!

So it's like almost two weeks of basically no change - even a bit of a gain.

Why would it be easier to lose weight in the U.S. of all places?

I've been tempted to tweak with my tried-and-true calorie/exercise formula,
but I'm resisting doing that.

Instead, I think I'm going to mix up the things I'm eating and try some more
variety. Maybe my body needs a change and is in a rut. Or maybe one of the
things I eat all the time has more calories in it than I think it does?

doug