A recent study reported on in USA Today, cautions consumers against falling victim to the Snackwell Effect when switching to energy efficient products and appliances. Just because something is more energy efficient, it doesn’t mean you should start using it more. If you’ve ever devoured a whole box of Fat Free Cookies in one sitting, you know exactly what I’m talking about. 

According to the study, just like dieters tend to use low-calorie foods as an excuse to over indulge, people who buy energy efficient products tend sabotage their energy savings by actually using the product more than they did before it was replaced with the efficient version.

Lights will be left on longer, more cloths will be washed, thermostats will be turned warmer in the winter and cooler in the summer—all because they are now more energy efficient.

As an example, Karen Ehrhardt-Martinez of the non-profit American Council for an Energy Efficient Economy notes people who purchase CFLs (or other energy efficient lights) lose between 5 to 12% of the bulb’s potential energy savings because they leave them on longer. Likewise, people who buy an energy efficient furnace lose anywhere from 10 to 30% of the savings because they raise the thermostat.

So what’s an energy saver to do? Buy the energy saving product, but don’t use it as an excuse to change your habits. If you always set your thermostat to 78 degrees in the summer when you are home, then LEAVE the thermostat at 78 degrees when you have that new energy efficient air conditioner installed.

Simply being aware of the tendency to sabotage your energy savings will most likely be enough to keep you from doing it. As for eating the whole box of cookies, that’s a whole other battle.

Click here to see the entire USA Today article.