You start with a hypothesis that is modifiable, and which is based on witness anecdotes describing what it looked like, where, when and how it behaved. You'll inherently have a tendency to filter out reports that don't fit your preconcieved notions. The process is both useful and fallable at the same time.
1.There is two prevailing hypotheses about bigfoot, it's either a bipedal pongid, or a member of the genus homo (hominid) , if it is a photographable biological entity.
2. It likely eats whatever is digestable, why be picky with such a high theorized caloric requirement?
3. It lives or can live whereever the habitat provides an escape to cover and seclusion with access to digestables, water etc.
Does that help any?
Me too.