If you can, regular vigorous sex is an amazing toner. Just two or three times a week and you'll be noticing quite an improvement in your physical stature, to the extent of more stamina, less body fat, an increase in muscle tone, the lot. Diet and exercise are hard to maintain sometimes, because we all know about the distractions, complications, time management, all that crap that stands in the way, and that's not even mentioning how flavor, taste, and deliciousness affect things. They can be unfun and tedious, giving you less motivation. Sex, though, is nominally something most people would get excited about, which means you're more inclined to do it. It won't be the most hardcore of weight loss, but you Will lose weight.