Bmi is pretty useless measurement. Bodyfat is much much better indicator. You at 154 are obviously in an nice range most likely at 150 I would likely be 5% BF at 5ft 6 due to carrying a lot of muscle.
I would think a 7 to 14 day fast would be plenty for WY.
Also you guys might want to think your lifestyle if you are pure vegans. Pretty good case for being an omnivore right there!