42 year old male...tired of sucking it in...

It's hard to say seeing as how I don't know how much you weigh... if you're 125 lbs, then losing 25 lbs is going to be tough
I started watching my portions back in November as a friendly challenge with a co-worker. I didn't see much progress until a buddy hooked me up with MFP. Now that I actually track what goes into my mouth... wow, what a difference. I've lost about 23lbs since the beginning of April; and I haven't even started cardio yet. This week I'm going to start working some cardio into my routine and expect to hit my goals in the next 3 months (weight that is.. going to continue to build muscle).
Currently, I'm at 168 (need to update my profile) and simply doing push-ups/pull-ups 3 times a week while watching my calorie intake. I was very out of shape when i started, could do maybe 8 pushups and 0 pull ups; last night i pumped out 92 pushups (in sets of 15) with a 1 minute break, and 12 pull-ups (sets of 3).
Based on my results... I'd say YES, you can achieve your goal by just watching your calories using MFP, but throw in a little more exercise and BLAM, you'll see a change in no time! Best of luck and STICK WITH IT!!!!

I think, in time, you will CRAVE more excercise. I went from walking 3 times a week to walking 4-5 days a week and throwing in 1-2 kickboxing classes a week. Now it's time for me to incorporate some weight training to tone things up a bit.