Maybe it's still a honeymoon thing for me but I've been trying out keto diet for few weeks and, anecdotally, now whenever I eat carbs I get a weird high. If you told me that people started farming to do it consistently, I'd believe you. Similarly, if I avoid carbs at all cost even for a day, by night I feel so bad that I must have some. Point is that as far as I can tell eating carbs is a habit/addiction as well, but much good has come from maintaining it.