And I just drink water at dinner, but that's because I really like water. (some nutritionalists would actually suggest drinking a lot of anything while eating a meal is actually hard on digestion.)
Woah, where did you get that? If by a lot you mean drinking whenever you feel thirsty that's definitely not true. If by "a lot" you mean too much, well... obviously. That's why it's called "too much."
There's a reason you often feel thirsty while eating: liquid helps to turn the food you eat into the nutritious slurry which actually can be digested by your body.
Do a literature review. Also, stop listening to nutritionists: many of them don't even have degrees in medicine.
http://ajpregu.physiology.org/content/258/2/R436.short http://gut.bmj.com/content/29/3/306.abstract
I mean I guess you could drink soft drinks with dinner, but to me that's a weird unnatural thing to do (super-sweet, and doesn't fit well either taste- or culture-wise with traditional European cuisine). Water is ok, and I do drink that sometimes.