Amazingly enough, quite a lot. There are several benefits to having sex and the most alluring benefit for women would be the fact that they get to lose weight, specifically, burn calories. More calories burned means more sex for him. I have gained a lot of weight from since I was single, before having met my husband, I was a puny 90 lbs. I now weigh between 130 to 140 lbs. I have not weighed myself in 6 months, maybe more. Ideally, I should weigh between 110 to 120 lbs, give or take a few pounds. I will make it a point to weigh myself tomorrow and will put my husband's suggestions to a test.
This is what I will base this test on, which by the way will make my husband extremely happy.
They say that on the average, making out will burn 144+ calories if you go the full length and orgasm.
Now, that does not take into consideration the level of activity that you go through to reach orgasmic levels. The more activity involved getting to the peak, the more calories burned.
I will weigh myself tomorrow and get a better benchmark to see if this will really help in my weight loss program. I just hope I don't eat more.
There are several more benefits that can be derived from having sex. But that's another story.