When he became determined to lose weight, Dr. Brian Weiner decided to change his eating and exercise regimes. "One of the first changes I made," explains Weiner, a gastroenterologist in New Jersey and assistant professor at Robert Wood Johnson Medical School, "was to give up my beloved ice cream."
Aiming for something lighter, Weiner replaced it with Italian ices. The cups at his supermarket listed their calorie content as 100—calculated by multiplying 25 grams of carbohydrate by four calories per gram. "One evening, in a burst of insight," Weiner writes, "I realized that this calculation was incorrect. The manufacturer of the ices did not calculate the energy required to melt the ice, and did not deduct this from the calorie calculation." By Weiner's math, he was actually only consuming 72 calories, or "icals," his term for the net caloric content of ice-containing foods after considering the calories that the body burns to produce the thermal energy that melts the ice.
Weiner reviewed the medical literature. "I found that no one has clearly identified this oversight," he writes. "I could not locate references to considerations of the implications of the energy content of ice as food."
After discussing the issue in detail with his son, an engineering student at Rutgers who vetted his father's calculations, Weiner submitted his story as a letter to editors of the widely-read medical journal Annals of Internal Medicine. They published it. In the article, Weiner said the idea could be of real importance to people trying to lose weight. It's meant as a supplement to overall diet and lifestyle that go into maintaing a healthy physical form. "While eating ice, you are serving two purposes," Weiner explains, "you are burning calories and not eating positive-calorie foods."
Now Weiner has also written an e-book, The Ice Diet. It's free—part of his stated wish "not to get lumped in with the counter-productive fad diet (snake oil) promoters."
As a practicing gastroenterologist, Weiner says he regularly avoids micromanaging food selection. He manages obesity as an illness and diets as part of a holistic approach to good eating. "I would usually cringe when patients brought up the weight loss diet of the day, usually some poorly documented and improbable strategy. I never thought I would be actively promoting and discussing weight loss diets."
But now he is, so, what's to know about using Weiner's ice diet?
When you eat a significant amount of ice, your body burns energy to melt it. Eating ice should, by the logic of this diet, also provide some level of satiety, if only so far as it physically fills space in the stomach and mouth.
By Weiner's calculations, ingesting one liter of ice would burn about 160 calories, which is the energy equivalent of running one mile. So you get to eat and burn calories. Ever since the death of upward mobility, that has been The American Dream.
What's more, it's probably safe. "Ingesting ice at this level should not have any obvious adverse consequence in otherwise healthy persons," Weiner, who trained at Johns Hopkins, writes. "For the vast majority of adults and children, there does not appear to be any contraindication to the use of the Ice Diet right now."
One piece of evidence for the safety of ingesting substantial amounts of ice, Weiner notes, comes from the case study of the 32-ounce 7/11 Slurpee, from which he concludes, "The ingestion of one liter of ice per day appears to be generally safe."