Joanna Weiss

In dieting study, human guinea pigs carry a lot of weight

They are an undersung lot, the people who submit themselves to pricks and prods and experiments.

Let us take a moment to praise the human guinea pigs.

They are an undersung lot, the people who submit themselves to pricks and prods and experiments, in the name of science and some extra spending cash. But they can make a difference. Take a study about dieting, from researchers at Boston Children’s Hospital and Brigham and Women’s Hospital, that has made headlines this summer.

The study, published last month in the Journal of the American Medical Association, helped participants lose a substantial amount of weight, then measured how they fared on three different kinds of diets: low-fat, low-carb, and “low-glycemic index,” filled with complex carbohydrates (fruits, vegetables, nuts, whole grains) that take a long time for the body to digest.


It turns out that the third diet — which keeps blood sugar and hormones steady — gives you the best and healthiest chance of keeping off the weight. Sounds simple, in retrospect. But for Michael Rogers, it was complicated.

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Rogers, 43, a father of four from Needham, is a research scientist who works in the building across the street from Children’s. He was nearly 40 in 2008 — 6’3”, just north of 250 pounds — when he happened upon a flyer near the elevator, asking for participants in a weight loss study.

Rogers was intrigued. He was, after all, a decent representative of America: His eating habits hadn’t changed much since his early 20s, but his exercise habits had. He had taken up cooking and “discovered the wonders of butter.” He had dieted before, but gained everything back.

So he tore off a phone number from the flyer, put it on his desk, and finally called six months later, lauching himself into a rigorous screening process. The study promised $2,500 in total compensation, the bulk of it after the work was complete. And the work was substantial: daily weigh-ins, a few weekend hospital stays, and an obligation to eat only the food researchers gave him, clearing his plate at every meal, every day for seven months.

Conducting the study was a feat of logistics, said Dr. Cara Ebbeling, a lead researcher. The planning began in 2004. The team had to choose menus, meticulously weigh and measure portions, and, most importantly, find people who could follow through. In the end, 32 people enrolled, and 21 finished.


Rogers turned out to be a model participant; he lapsed only once, in the first week, eating a handful of cashews in a coworker’s office. In a way, he said, it was “trivially easy to lose weight” when he didn’t have to make any decisions. He would simply bring home bags of food that the researchers gave him. (His kids loved to open the packages to see what Daddy was eating each day.)

During the weight-loss phase of the diet, the portions were small and the sodium was light; he compensated with copious amounts of Mrs. Dash. During the low-carb phase, he started having “these wild dreams” about pasta and pizza. During the low-fat phase, he ate a bowl of mashed potatoes that he thought would never end, and remembers “thinking there’s no way I’m gonna be hungry after this — and feeling hungry 90 minutes after.”

Then — cue the sound of angels singing — he went on the low-glycemic index diet. He found himself pleasantly hungry about an hour before meals, pleasantly full for hours afterward. He learned to like brown rice and steel-cut oats.

Those were his impressions. Then there are the data on the gases from the air he exhaled in those hospital stays, and on the isotopes and hormones measured in his urine — levels that are strikingly consistent with those of the study’s other subjects.

“It’s one piece to a really large puzzle,” Ebbeling said. “It says that the body does not handle all calories exactly the same way.”


In a nation that’s about to be overtaken by obesity, that’s useful to know. For one guy in Needham, it has been a life-changer. When I met Rogers last week, he weighed 213 pounds — five pounds less than when the study ended. He has taken up long-distance running again. His family has shifted to steel-cut oats and whole wheat bread.

They are an undersung lot, the people who submit themselves to pricks and prods and experiments.

Now, Ebbeling and her colleagues are looking for participants in two new studies: Comparing diets for weight loss, and measuring the health of sugar-sweetened beverages. Any takers? You’ll help more than just yourself.

Joanna Weiss can be reached at weiss@globe.com. Follow her on Twitter