right now only jungler that can farm with healthy hp are the ones who are OP and that's kindred graves and nidalee,
Nidalee can out farm you and still be in good shape to go into your jungle and take your farm, it's a joke there are no junglers(except the ones I mentioned) that can keep up with her. she will out farm you so hard that she would be ahead in levels and gold and destroy you with long range spreads and 50% heals.
If you nerf nidalee other champions will be able to be good tier junglers, she's suppressing all the other good junglers early in the game.
If you don't want to nerf nidalee then the only way to do this is giving an item some sort of sustain and extra damage to jungle creeps, to keep up with the early farm pressure these 3 junglers provide. Remember that season 5 jungle items that did an Aoe smite, that was amazing to use if you needed to farm quite fast and use it for wave clears. Bring the item back but puts its passive into another item like the new yellow gem or warriors