Training for a half marathon and weight loss

I'm training for a half marathon and while I haven't increased my daily calorie allowance, I have had to change my macro distribution with more carbs on days I run longer distances.

Does running longer distances slow, or halt weight loss? I was losing faster when I wasn't running at all; just lifting weights and walking briskly. Since adding consistent running (about 4 months ago), I've experienced very slow weight loss.

Anyhow, just looking for people with similar experiences who can help me out.

Before anyone asks, no, I am NOT eating more calories.