Three Weight-Loss Studies You Should Know About

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.

None of the participants was obese when the study began, but some were classified overweight by their Body Mass Index, a ratio of height to weight. The team, led by Susan Racette, assistant professor of therapy and medicine, divided the participants (all were part of CALERIE [Comprehensive Assessment of Long-Tern Effect of Reducing Intake of Energy]) into three groups. One lowered calorie intake by 20 percent, the second increased physical activity 20 percent and the third did nothing. All three were followed for the whole year while they kept food diaries, tracked exercise and were weighed at regular intervals.

Before the study, researchers recorded baselines for what the subjects were normally eating and how much they were exercising. Saturdays were their downfall, with participants consuming the most calories on that day. And they were generally bad calories: 36 percent of the total came from fat, compared to less than 35 percent the rest of the week. Even normal-weight participants would gain nine pounds a year if they continued that pattern.

After the study began, Saturdays were still a problem. The group that was cutting down on calories still took in more on Saturday and the group that was exercising more actually ate more on both Saturday and Sunday. The results were not good: The dieters stopped losing weight on weekends and the exercisers actually gained weight.

The researchers are still trying to figure out how to help dieters overcome this weekend slump, but one tip is to weigh yourself daily so that you're more aware of how much you are taking in. It's also important to plan ahead if you know you're going to a party or other event where fattening food will be around. Bring your own food or eat something healthy beforehand so you're not starving (and vulnerable to snacking) when you arrive.

Also, pay attention to the amount you're eating—especially portion sizes. Many restaurants, for example, offer meals that could easily feed two. As a guide, one portion of meat (about three ounces) is roughly the size of a pack of cards.

3. Work It Out
Many employers consider obesity to be a workplace problem because too many excess pounds puts employees at risk for heart disease, diabetes and perhaps even dementia. That affects the bottom line in the form of increased health insurance costs. According to the National Business Group on Health, more than 10 percent of employers' health costs are obesity-related. That's why a growing number of companies have entered the battle of the bulge.

A recent review of these programs in the July-August issue of the American Journal of Health Promotion found that work-based weight-loss programs were effective. In general, participants lost an average of 2.2 pounds to almost 14 pounds. Workplace programs also offer the advantage of a built-in support group since most employed adults spend almost half their waking hours at work. Many offer incentives to the most successful losers.

"It's very easy for people to get discouraged or to yo-yo and jump back and forth," says Aaron Day of Tangerine Wellness, a voluntary incentive program that rewards employees who lose weight and maintain a normal weight. Dieters get individual and team rewards.