I would say "yes"..... i too am doing this diet because it's a healthy way to eat. I've had digestive issues since birth, and finally i'd had enough and thought to myself " what did cavemen eat?"..... of course they ate only natural foods, nothing processed. Unfortunately my digestive problem is still there, but i no longer feel bloated, nauseous, sluggish, headachy.
Do make sure you get the balance of nutrients right...... make sure you are both getting enough calcium for example from green vegetables and fish, and enough iron etc too. If you're at all worried you can always take a vitamin and mineral suppliment.
I would say start at stage 3 because you're not doing this for weight loss.
Good luck, and let us know if you need any more advice

Nicki