I don't struggle with my weight like some people do fluctuate by about 10lbs if I'm not careful.  What I do notice, especially as I have got older (mid 30s now) is that when I really get into an exercise routine I have to be careful not to start eating too much more.  I also notice that during these times my body tends to got lots firmer and stronger and I don't start loose weight for several months.  I think I finally got to the point of loosing weight about a week ago, which really coincides with my endurance increasing to the point that I can put in some serious time working out.  Last week I was able to run three miles four times and I actually want to run today too.

What I am saying is that for some people it takes more time to get to the point of loosing weight.....now that I'm to that point I'll have to be careful not to loose too much.  I'm about 7 lbs my high school weight but I'm 4 inches taller.