Adding bigger wheels to your truck or vehicles does increase the ground clearance somewhat so you can go over obstacles much easier than when your vehicle sat lower to the ground with your current tires and wheels.
However adding a lift kit to the vehicle will increase the ground clearance more than just adding bigger wheels and tires.
Also do note that when you do add bigger tires and wheels to your vehicle that your fuel mileage will be decreased somewhat and your speedometer will read around 10 to 15 miles under the speed you're actually traveling at.
So you could be showing 45 MPH on your speedometer while in reality you're going at a speed of 60 MPH.
So I would recommend just adding a lift kit to your vehicles suspension to lift the vehicle up more in the air to increase the ground clearance without decreasing gas mileage or fuel mileage or affecting your speedometer.