Not so fast, you low-fat-frozen-yogurt fiend! Labels are deceiving: people often eat more calories of low-fat foods than of regular, because they eat a lot more of them, period.
Next, participants were shown a measuring cup each of granola and M&Ms, labeled “regular” or “low-fat.” As in the first experiment, those with the low-fat cups thought the appropriate serving size was 25 percent bigger than those with the regular cups, and believed that the low-fat foods were much lower in calories than they really were. They also thought they’d feel less guilty eating the low-fat foods.
Finally, participants watched a movie while munching on a bag of granola. Those with low-fat granola ate 50 percent more! Participants also ate much less if the bag indicated that it contained two servings rather than one, even though the actual amount was the same. And you guessed it…participants underestimated the number of calories they’d eaten, especially with the low-fat granola.
The bottom line: Beware the low-fat label, and heed the serving size!