yes. all food groups are equally important.
americans have the worst diet these days. get this. i used to teach jr. high english in japan. their lunches from the cafeteria are regulated to be a well balanced healthy. tons of veggies, and the right amount of fats and proteins. this was instituted when japan lost in WWII.
decades later the current generation of japanese people have started growing taller and getting bigger. most of my 7th grade students were taller than me, i'm only 5'5'' but still.
look at americans today and you'll see were still big, but in GIRTH for the most part because we've started eating crap all the time. "more HCFS and empty carbs please, with some saturated fat on the side please"
eating in a balanced way from ALL food groups has everything do to with it.