[WillPostForFood]

Exercise makes your hungry, so it is particularly hard to eat less when exercising more. So it doesn't work for most people, because they aren't able to to both.

http://well.blogs.nytimes.com/2016/11/28/why-do-i-gain-weigh...

The problem, most scientists agree, is that exercise makes us want to eat. Many studies have shown that if people start a new exercise program, their bodies begin to pump out much higher levels of various hormones that increase appetite. This reaction seems to be most pronounced if someone starts a new, moderate, aerobic exercise routine. (There are hints in some studies that intense exercise, such as interval training, may dampen appetite. But the relevant studies have been few and small.)