To answer the question of why does it try to get you to lose weight while doing strength exercises, that is quite simple.
Unless you haven't exercised in a long time, when you are doing a strength exercise routine but eating under your maintenance calorie level, you will lose more fat than muscle, but you will lose both. If you continue the same routine but eat more than your maintenance level you will gain muscle (and fat). So, you aren't really building muscle unless you are eating enough.
Ultimately it doesn't matter what exercises you do, it comes down to calories eaten vs. calories used.
Anyways, I put in that I'm 5'11" and the upper range for me in normal is ~178. Either you entered your height wrong, or you weigh more than you are saying you do.