What Works

Remember when you vowed that this would finally be the year you'd shed those extra 10 or 15 (or more) pounds before beach season? If you are like most dieters, your resolution lasted at least a few days, maybe even a week or two, and then … well, you know the rest of the story.

You may think this is just your problem, but it's a major public health issue. With two-thirds of American women classified as overweight or obese, excess pounds weigh heavily on the minds of researchers. And that's good for those of us still struggling to get and stay slim. Here's the skinny on the results of three of the most recent weight-loss studies that may help in your own journey down the scale.

1. Dear Diary
There's been lots of research on the importance of being conscious of how much you eat. One of the best ways to accomplish that is to keep a food diary—an honest one. It doesn't help if you're "forgetting" to write down that piece of chocolate you swiped when no one was around. "You think people know what they eat, but they don't," says James Hill, director of the nutrition center at the University of Colorado at Denver and co-founder of the National Weight Control Registry, which studies successful dieters. Keeping a diary "forces you to look."

In a new study by the Kaiser Permanente Center for Health Research, scientists found that diarists actually doubled their weight loss. Not only do they see how much they are eating, they also can spot problem areas, says research psychologist Victor Stevens, senior investigator for Kaiser. The study included nearly 1,700 participants from around the country; 79 percent were obese and the rest were overweight based on their BMI.

Julie Satterwhite, 46, of Portland, Ore., one of the participants in the study, weighed 203 pounds at the start. Keeping a diary helped her get down to 150. "I was the classic yo-yo dieter—lose 10, gain 20," she says. She tried everything—Slimfast, Atkins—but she just kept gaining. It was frustrating and bewildering until she began writing down every bite. "It was amazing to me how much more conscious I was of the food I was eating," she says. Her biggest wakeup call was realizing that her beloved bagel with an egg and cheese on top cost her 630 calories. Now, breakfast consists of a cup of high-fiber cereal, milk and four ounces of orange juice. Recently, she gained back some of the weight when she stopped keeping her diary because of work-related stress. But this time, she knows how to fight back: She's restarted the diary.

2. Weekend Weakness 
When researchers at Washington University in St. Louis followed the eating and exercise habits of 48 adults between the ages of 50 and 60 for one year, they discovered some fascinating trends in weight loss—and gain.