Why Low-Fat Labels Make You Overeat

Using only two words, I bet I could get you to overeat a snack you don’t even really like.
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Those two words would be “low fat.”

We’re living in a world of fat-free, carb-free and sugar-free snacks. Most of the time, if we think they are at least low fat, we think “it must be good for us” —even if the snack is loaded with sugar.

When Nabisco came out with SnackWell’s, a line of no-fat and low-fat cookies and crackers, they flew off of shelves, gobbled up by the people who believed they could eat them until they magically whittled down into a supermodel. Six months later and about 6 pounds heavier, the low-fat fanatics finally realized that these cookies had about only 30 percent fewer calories than regular cookies.

This happens all the time. Often the fat-free version is not much lower in calories than the regular version. For example, each low-fat Oreo cookie has 50 calories. The regular version has just over three calories more.Low-fat labels can lead us to mindlessly overeat a product with guilt-free abandon.

Take granola. Where low-fat granola is indeed lower in fat, it is only about 12 percent lower in calories. It does not take a lot of mindless munching to scarf down an extra 12 percent of granola, especially while thinking you are doing your body good.

In one study, a French colleague, Pierre Chandon, and I invited people to watch some commercials and a video episode of the “Dukes of Hazzard.” We gave them bags of granola that were labeled as either “Low-fat Rocky Mountain Granola” or “Regular Rocky Mountain Granola,” as we described in the Journal of Marketing Research. In reality, all of the granola was low fat. While people watched the video, they ate the granola. Those given what was labeled as low-fat granola kept munching long after the other group stopped. After the movie, we weighed the remaining granola to see how much had disappeared. It turned out that those eating what they thought was low-fat granola ate 35 percent more, which translated into 192 more calories. When we offered them low-fat chocolate, they loaded up on 23 percent more calories.

The low-fat label tricked people into eating more than if the product had a regular label.

The cruel twist is that these labels can have an even more dramatic impact on those who are overweight. People who are overweight and eat more than their thinner peers are in danger of really over-indulging when they see something with a low-fat label. The problem is that when we are looking for an excuse to eat something, low-fat labels give it to us.What’s worse than overeating a snack?Overeating one we don’t even really like that much. Few low-fat snacks are nearly as tasty as their regular version.So rather than overeating something you don’t even really like, enjoy the regular version —but only half as much of it.