New research sheds light on effective ways to keep excess pounds off
If you have type 2 diabetes and you're struggling with an expanding waistline, losing excess pounds can lower your blood glucose levels and reduce your risk of developing cardiovascular disease. The good news is that many different types of diets and strategies can potentially help you lose weightand there's a good chance you'll find one to help you trim down. The bad news is that most people who lose a significant amount of body fat eventually gain it all back.
Still, plenty of formerly overweight or obese people lose a significant amount of weight and keep it off. What's their secret? Solid research is beginning to reveal how some people with type 2 diabetes manage to shed fat and maintain long-term weight loss.
Many studies have examined the role of diet, exercise and other lifestyle interventions in fighting obesity, but most have lasted a year at most. While such research has provided valuable information about how people lose weight, it has offered relatively few clues about how to sustain weight loss and the long-term benefits of sustained weight loss. But that is changing.
One of the goals of a recently terminated clinical trial called Look AHEAD (Action for Health in Diabetes) was to find out what it takes to maintain weight loss over the long term. Look AHEAD was one of the largest and longest studies of its kind ever conducted. It involved 5,145 men and women (average age: 59) with type 2 diabetes, who were followed for up to 11 years at one of 16 medical centers across the United States, including Johns Hopkins.
At the start of the trial, all participants were overweight, meaning they had a body mass index (BMI, a measurement of body fat) of 25 or higher. And many were severely overweight, or obese, at the outset of the study (BMI of 30 or higher). The average starting BMI among the men and women was 36 (for a person who is 5 feet, 9 inches tall, that would mean weighing 243 pounds.)
Researchers divided the participants into two groups. The first group attended three group educational sessions each year, where they received general information about diet, physical activity, and social supportthe type of advice given to most people with type 2 diabetes. The second group took part in an intensive lifestyle intervention program with a goal of 7 percent weight reduction. Key elements of this intervention included:
- A low calorie diet (between 1,200 and 1,800 calories per day, depending on a person's starting weight) that limited intake of fat (especially saturated fat, which increases the risk for heart disease) and included plenty of protein (which studies suggest helps with weight loss by increasing satiety, or a sense of “fullness”). Dieters were also encouraged to replace one meal and one snack daily with liquid shakes or meal bars.
- A goal of at least 175 minutes per week of moderate physical activity, such as brisk walking.
- Frequent weigh-ins and individual and group sessions with a counselor (either a registered dietitian, behavioral counselor or exercise specialist), who assisted participants in setting goals and monitoring progress.
In 2007, the Look AHEAD researchers reported that at one year, more than half (55 percent) of the men and women who followed the intensive program met their 7 percent weight loss goal. And nearly 40 percent exceeded that goal by losing 10 percent or more. On average, people who took part in this plan lost 8.6 percent of their body weight. By comparison, in the usual care group, only 3 percent lost 10 percent or more and only 7 percent lost 7 percent or more of their body weight. On average, participants in this group lost 4.8 percent of their weight.
How did the groups compare when it came to maintaining their weight loss? Updated findings in 2010 in the Archives of Internal Medicine reported that many people in the intensive group regained some weight over a four-year period. But the typical participant in this group sustained a 5 percent weight loss. Even more impressive: 42 percent of those who lost 10 percent or more of their initial body weight kept it off for four years and another 30 percent of the participants kept off 5 to 9.9 percent of their lost weight for the same length of time.
By comparison, the typical usual-care group member who lost weight at year one was able to sustain a 1 percent loss.