I have seen naturopaths myself before and have clients who have seen them too. They can really help if you have a sluggish metabolism; IE: If you are doing all the right things such as eating properly and exercising regularly but still find it hard to shift the weight. In this case you may have a hormonal problem and a naturopath can help to diagnose the problem if this is the case and recommend supplement to help correct the imbalance.
They can also help you work out if you have any food intolerances such as wheat or lactose for example. If you do, eating those types of foods could cause you to hold onto excess weight and/or slow down your metabolism.
Having said that, naturopaths can be quite expensive and there's no substitute for eating the right foods and exercising regularly. Listen to your body and it will tell you which foods don't work for you. For example, if you get a lot of bloating after eating bread and pasta (a common problem) then try eliminating that from your diet for a while and see if it helps.