My shbg was already high, but fasting and a vegan diet increased it about 30-40 points.
It's usually high 40s, low 50s and after trying vegan it was about 88.
And I did the fasting and vegan for liver cleansing/ body detox hoping it would lower shbg, but it did the complete opposite.
Things you'll want to avoid, if you want to increase shbg, are sugar and fructose, which turn off the gene that's responsible for making or triggering shbg.