I think the way the guidelines are phrased is what makes so few people achieve them. Both DC eat plenty of vegetables. Just not in their lunch boxes. DS quite likes a salad so I sometimes send him in with a small salad of lettuce, cucumber, peppers and maybe some feta, but DD doesn't like any raw veg.
However, at home we eat lots of veggies, both on the side and as main dishes. DD's selection is more limited than I would like, but she eats the standard peas, corn, carrots, broccoli and is quite happy with dishes with "hidden veg" such as bolognaise etc. So I can't get too worked up about it. Putting some veg in her lunch box is a complete waste of time though.
Also, I thought healthy eating was based on the nutritional value of, at the very least, a full day, but actually more like 3-4 days? People don't get scurvy after one day after all.