By Melissa Healy
Los Angeles Times
As if people needed a reminder that losing weight is hard and maintaining weight loss is even harder, a study has found that for at least a year, subjects who shed weight on a low-calorie diet were hungrier than when they started and had higher levels of hormones that tell the body to eat more, conserve energy and store away fuel as fat.
The report, published Wednesday in the New England Journal of Medicine, helps explain why roughly 80 percent of dieters regain lost pounds within a year or two of losing them and, sometimes, regain more.
After weight loss, "multiple compensatory mechanisms" spring to life, the study shows, and work together to ensure that weight loss is reversed.
The researchers, led by Joseph Proietto of the University of Melbourne's Department of Medicine, write that more than one solution to obesity will likely be necessary: "a combination of medications" that will have to be safe for long-term use.
The study paints a "very comprehensive" and "really discouraging" picture of the breadth of the body's response to weight loss, said Dr. Daniel Bessesen, an endocrinologist and obesity researcher at the University of Colorado Hospital.
The study enrolled 50 obese men and women without major health problems and put them on a strict low- calorie diet for eight weeks.
Within two weeks after that diet, and again a year later, researchers measured subjects' blood levels of nine hormones that affect appetite and metabolism, and asked subjects about feelings of hunger.
Even 52 weeks after subjects had completed their diets and were struggling to maintain their loss, their hormones were sending a single message: Eat more.