High protein, low glycemic index diet helps keep pounds off

November 29, 2010

The secret to weight loss is simple: Cut calories and the pounds will disappear. But keeping the weight off is far more difficult. A new study from Europe reports that people who had lost weight were less likely to regain it if they ate a diet slightly higher in protein and a little lower in simple carbohydrates than a typical diet.

The results, published last week in the New England Journal of Medicine, come from a two-part study that randomly assigned more than 770 people who had just lost an average of 8 percent of their body weight to continue with one of five maintenance diets. The diets varied by how much protein they included and where the foods fell on the glycemic index, which is a measure of how foods increase blood sugar levels. Low glycemic index foods, such as whole-grain breads or pasta, do a better job keeping glucose and insulin levels under control than high glycemic index foods such as white bread or sweets.

After six months, people who followed the high-protein, low glycemic index diet were more likely to keep their weight stable or continue to lose weight than the people who ate a low-protein, high glycemic index diet. The difference between the groups averaged about five pounds.

Perhaps equally important, only a quarter of the people in the high-protein, low glycemic index group dropped out of the study compared with a third of those in the low-protein, high glycemic index group.

“If an individual is feeling less hungry, less tired, and more energetic on a lower glycemic index and higher protein diet, they are more likely to stay on that diet,’’ Dr. David Ludwig, an obesity specialist who directs the Optimal Weight for Life program at Children’s Hospital Boston, said in an interview. He has written an editorial about the study with colleague Cara Ebbeling that also appears in the New England Journal.

Ludwig said the European study reinforces what smaller studies, including his own, have shown about higher-protein, lower glycemic index diets. Taken together, the findings suggest that the diet may help people adjust to biologic changes that result from weight loss.

“We can ignore hunger for a while but that becomes progressively more difficult,’’ he said. “Basic biologic changes in our metabolism occur with low-calorie diets that tend to oppose ongoing weight loss, specifically a drop in metabolic rate.’’

Low glycemic diets metabolize blood sugar in a way that leaves people feeling full, Ludwig explained, keeping hunger at bay and, at least according to preliminary research, helping to maintain a person’s normal metabolic rate. Protein can also help a person feel full.

Longer studies are needed to see if the benefits last, including whether the diet has long-term effects on risk factors for cardiovascular disease or diabetes. But the lower dropout rate for the high protein, lower glycemic index diet is a good sign.

“It was either easier to follow or they were experiencing greater benefits and felt more motivated,’’ he said. “Ultimately that’s the holy grail of weight loss . . . to keep people motivated so they stay on the diet.’’ E.C.

Study links diabetes, depression

It makes sense that someone diagnosed with a serious illness such as type 2 diabetes might feel depressed about it. In the same way, it’s easy to imagine that people who are depressed might be less active and gain more weight, which are two risk factors for type 2 diabetes. Researchers from Harvard who followed a large group of women before they developed either illness found that a woman who had one condition was more at risk for the other.p

An Pan of the Harvard School of Public Health led a group that observed more than 65,000 women over age 50 in the Nurses’ Health Study. Participants were asked, among other things, if they had depression or diabetes. Findings were reported in the Archives of Internal Medicine.

After 10 years, researchers found that women with depression were about 17 percent more likely to develop diabetes. Women who were taking antidepressants had a 25 percent higher risk of developing diabetes compared with women who did not have depression.

 

Women with diabetes were 29 percent more likely to develop depression. E.C.

 

Little progress on patient-safety front

Soon after the 1999 report “To Err Is Human,’’ about widespread hospital errors, a movement to prevent medical mistakes flowered across the country. But a recent New England Journal of Medicine study led by Boston researchers shows that despite efforts, progress is hard to find.p

Dr. Christopher Landrigan, a patient safety researcher at both Children’s Hospital Boston and Brigham and Women’s Hospital, led a team that studied more than 2,300 patient admissions to 10 hospitals in North Carolina between 2002 and 2007. They picked that state because of its active role in safety training programs.

 

There were 588 instances of harm suffered by nearly 1 in 5 patients admitted to all 10 hospitals. Some patients had more than one problem, and a little more than half of the problems required them to stay longer in the hospital. Seventeen cases were life-threatening and 14 patients died. More than half of the harms were considered preventable. The rate of errors did not decline over the six years studied.

 

E.C.