The big diet study in this week's NEJM seemed like a good target for news of the obvious, but since the mainstream media is giving it tons of positive attention ("The secret to weight loss," screamed cable news), we'll play along.
In short, researchers assigned 800-some patients to three different diets with varying proportions of fat, protein and carbohydrates. They found that a) patients weren't very good at sticking to the instructions so they ended up eating more similarly than intended and b) people lost weight at the start of diets but then started gaining it back within two years.
So, the good news is that successful weight loss is not complicated (any kind of diet works as long as it's lower in calories), but the bad news is that it's really hard. As an accompanying editorial said, "even these highly motivated, intelligent participants who were coached by expert professionals could not achieve the weight losses needed to reverse the obesity epidemic."
Need some humor after that depressing news? Check out the "Clinical Directions" comments that accompany the study on the Journal's website. Readers offered a number of interesting weight-loss techniques, including eating like a caveman, following the advice of Muhammed, and carrying a tape measure everywhere.