An important distinction
"The naturalist understands not only that we are not exceptions to natural laws, but that we don’t need to be in order to secure any central value (freedom, human rights, morality, moral responsibility) or capacity (reason, empathy, ingenuity, originality). We can positively affirm and celebrate the fact that nature is enough. Indeed, the realization that we are fully natural creatures has profoundly positive effects, increasing our sense of connection to the world and others, fostering tolerance, compassion and humility, and giving us greater control over our circumstances. This realization supports a progressive and effective engagement with the human condition in all its dimensions."
The naturist, on the other hand, advocates and practices the non-wearing of clothes at every opportune moment.
Needless to say, naturalists can be naturists and vice versa.