this. my dad lost weight roofing one time and everybody thought he was too skinny. he merely lost his gut. your numbers don't sound terribly underweight to me and when i plugged it into BMI (not the greatest, but doesn't hurt) it was 20.0. So still not technically underweight. Eat more, including steak in front of your folks (yum) and don't worry about it.
Originally Posted by Fatkid
28 yrs, 5'8.5"
started primal 1/23/11 @ 143 lbs, couldn't do a knee pushup
3/13/11 138 lbs, 30 knee pushups, yeah!