Normal weekdays, no. When I am on work travel occasionally especially if meeting with colleagues and there is a nice place I will usually have a beer with my meal.
A Beer or a glass of wine is very civilized when eating out for lunch and improves the taste of food
And of course, as everyone else has noted, I judge the situation.. Having a beer with lunch is most definitely not a fireable offense where I work.. Although being on-site "Under the influence of drugs or alcohol" is against policy (Federal land, FFRDC)