When 43 women and men agreed to photograph every morsel before they ate it for one week (and keep a written food diary as well), researchers at the University of Wisconsin–Madison found the results eye-opening—and diet-changing. The mealtime shutterbugs, all of whom considered themselves healthy eaters, discovered that their portions were too big, their meals bereft of fruit and vegetables, and their snack choices calorie-laden. Rather than continue to photograph their bad choices, many chose to eat something else instead.

"The act of taking a photo made them so much more aware of what they were eating," says lead researcher Lydia Zepeda, PhD, a professor of consumer science at the university. "They weren't trying to lose weight, but many said they didn't want an unhealthy snack or a second helping at a meal if they had to take a picture of it."

Though the success of keeping written food diaries is well documented (they doubled weight loss in a recent study from the Kaiser Permanente Center for Health Research), Zepeda theorized that a photo diary might be even more motivational. "With a written diary, there is nothing you do in the moment. You eat the food and write it down later," she says. "With a photo diary, you can still change your mind and choose fruit over cake."

Or as one study volunteer said, "Who wants to take a photo of a jumbo bag of M&Ms?"

Zepeda's group used film cameras, but she recommends going digital—the camera in your cell phone may be the simplest option, and you'll have images to look at immediately. To get a handle on what you're eating, take a picture of everything you consume over the course of an entire day, she suggests. "Don't change anything. Choose the foods you would normally eat so you can see your eating habits," Zepeda says. Then continue to snap for at least a week as you improve your diet. (If you're concerned about your food choices, Zepeda recommends reviewing your photos with a registered dietitian.) And anytime your weight loss plateaus, bring out the camera again.