Is it hard for the body to digest raw food such as salads in comparison to steamed or boiled veggies ? what you suggest?

Both are fine: Our bodies were designed to be able to get nutrition from food even before we learned to cook. Life's already difficult enough without people making problems for folks who've discovered how much fun it is to eat their vegetables raw. Truth be told, i'm glad you're neither living entirely on vegetables, or ignoring their goodness like so many folks do today.

Some, maybe yes: Some vegetables like broccoli are easier to digest if lightly steamed or blanched before eating. This is because they contain chemicals that protect the plant but interfere with nutrient absorption. Boiling may over cook your vegetables; if you do this, use the liquid in soup or some other way so that you retain the leached-away nutrients.