Problems that appear only after eating

I have a chronic problem while dieting.

The problem is that I get really sleepy after meals.

I get sleepy about halfway through eating.

I'm not full, but I'm sleepy, so it's tough.

So I always prepare enzymes or blood sugar-lowering supplements before starting to eat, but

I know in my head that I should move after finishing my meal, but I'm too tired, so I just sit there and end up falling asleep.

Do you happen to have your own tip for when you feel sleepy after a meal? I'd love to learn it.