Most likely an evangelical Christian or Mormon who is into healthy eating. They are fairly common (even outright vegetarians) on social media in my experience.
This. We (myself included) tend to stereotype Evangelicals as driving pickup trucks to McMansions in the exurbs, but they have a pretty substanstial crunchy granola component.
It's important to distinguish such people from the typical "Evangelical" who just goes to a megachurch on Christmas and Easter, skipping every other Sunday because it would interfere with watching sports, but never hesitates to use his "faith" to justify every racist, bigoted opinion he holds.