My belief that media more often muddies that water, rather than clarifying it, is continually reinforced.  This month, Time magazine featured an article stating that not only will exercise not make you thin, it may make you fat.  The reasons given were that people often feel hungrier after exercise so they tend to eat more and that people tend to reward themselves with food.  While there is some truth here, the article is more than a little misleading.
To her first point that exercise makes people feel hungrier. . . good, it should!  This means these people are working at an intensity and for a duration great enough to deplete their glycogen, or energy, stores.  Not altogether different from the body’s need for fluid replacement on a hot day, the body requires that energy, or calories, be replaced.  There is a whole science, referred to as nutrient timing, dedicated to what to eat and when to eat it in order to ensure the body functions optimally.  Proper nutrient timing, along with good food choices, aids the body in  the oxidization of fat as a fuel, the ability to recover from exercise bouts and other stresses, and performance.  To oversimplify all of this to ‘exercise makes you hungry therefore it makes you fat’ is simply sensationalism.
As to people rewarding themselves with food, this has more to do with psychology than it does with exercise.  The vast majority of people in this country, fat or thin, have extremely poor eating habits for a number of documented reasons not the least of which is their psychology surrounding food.  As the author of the Time article points out, it is fact that our population is exercising more and it is a fact that our population is getting fatter.  What is left out of this equation is what has occurred in our diet.  I’ll give you an example, many years ago, low fat diets were all the rage so the food industry responded by creating lowfat or nonfat alternatives of their ‘junk food’ items.  Following the conventional wisdom of the time and being the good consumers we are, people began substituting their poor nutritional choices with low fat versions of those nutritional choices.  In some studies I read, they argued that people actually ate more of the low fat food because it wasn’t bad for them.  I’m not advocating eating only food that’s good for you but I am suggesting that junk food is junk food, no matter how you slice it, it’s not good for you.  This is only one example of the justifications people give for eating poorly.  Treating yourself to excess food, or junk food, because you exercised ‘so you deserve it’ is yet another example.  No matter how people justify the choices they make, exercise is not to blame.
In the American College of Sports Medicine’s press release responding to the TIME Magazine article, John Jakicic, Ph.D., FACSM said, “The statement ‘in general, for weight loss, exercise is pretty useless’ is not supported by the scientific evidence when there is adherence to a sufficient dose of physical activity in overweight and obese adults.” Jakicic chairs a committee on obesity prevention and treatment for the ACSM and helped write an ACSM Position Stand on strategies for weight loss and prevention of weight regain for adults. Jakicic continues, “There is strong evidence from the majority of the scientific literature that physical activity is an important component for initial weight loss.”