Weight loss & beer

I’m in the middle of a weight loss programme. I know I shouldn’t drink beer with it, but every 1-2 weeks I like to have an afternoon/evening out with a few beers.

Question is – which type of beer is the least of an issue? (I live in the UK if that helps)

Have drunk lager the last few years, but it always makes me feel gassy and horrible. I quite like real ales, but always found those go down too quickly.

How does Guinness rate? I know calorie content is similar to lager – do the nutrients make it a marginally better choice?