Frozen usually has much less sodium than canned. Any fresh food is superior to other. Green veggies usually have less carbs and more fiber, both good things for losing weight. Cooked veggies are usually easier on the stomach than salads. Steamed is better for retaining nutriants than boiling. Take vitamin supps.

broccoli, spinache, green beans, fresh beans (kidney, black eye etc..)
brussel sprouts...

Frozen veggies can be better than fersh in one respect
if you canbuy fresh vegetables that are fresh and not left in the store over night and what not, and eat them on the day of purchase they are good

most frozen veggies now (especially by reputable brands) aer frozen by the source meaning they are forzen very soon after being picked the more nutrients are locked into them