Hey and welcome to the forums!
When you say following the PB you just mean the style of eating or are you incorporating the work out ideas as well?
Keeping your carbs in check will help, try shooting for under 100.
Sprint 2x a week, lift heavy things, and do a lot of walking, easy bike riding, and resting.
make sure you eat enough fat, it should be 60-70 percent of calories are from fat
i have only been doing this for a couple of weeks, and have been trying to gain weight, but i hope this helps!