In the Dr. Phil category of posts

A problem I have is:

I exercise, I get hungry, I eat. Which means I eat more when I exercise. Which again means that overall I have been (slowly) gaining weight over the years. I am constantly struggling to reverse the process, but the funny thing is that when I take exercise breaks, like vacations and such, I tend to loose some weight.

I know the solution to this is straightforward: EAT LESS, idiot !!

….But still, it has left me wondering whether putting an emphasis on exercise is correct when advising people on how to loose weight. Eating habits seems to me to be the key element rather than exercise,  – exercise may even slow down the weight loss process.

I would be happy If I am corrected on this, since I would like to carry on exercising. And while you are at it, I would love to be directed towards some convincing data that tells me whether:

The overall physical activity level has gone down in recent years ?

And if so: have the number of calories consumed gone up proportionally more than activity has gone down ?, – enough so to explain the epidemic nature of overweight in the western world ?