Originally created 03/16/04

'South Beach Diet' author explains logic behind plan



Arthur Agatston admires the cave man, at least for his eating habits.

Straying from the "hunter/gatherer" foods to highly processed carbohydrates has put many people into a "pre-diabetic" state that is fueling the epidemic of obesity and diabetes in the United States, said Dr. Agatston, the author of the wildly popular South Beach Diet.

He made a rare trip to University Hospital on Monday to speak to cardiologists and staff and later spoke to a sold-out crowd at the Radisson Riverfront Hotel Augusta.

Ancient man relied on a wide variety of plants and vegetables and lean meats that are higher in omega-3 fatty acids than grain-fed meats today, Dr. Agatston said.

"It seems so clear that we evolved literally over millions of years to eat a certain way. You change it at your own peril," he said. "So much of the Western diseases we're seeing might be due to changing the diet."

In particular are highly processed carbohydrates, such as white bread, that are quickly absorbed as sugars and cause a spike in blood glucose levels, which quickly triggers the pancreas to secrete large amounts of insulin to convert it. That conversion can actually cause blood-sugar levels to crash, which leads to the craving for more, a response called "reactive hypoglycemia," Dr. Agatston said.

"Once your blood sugar drops like that, you look for the worst kind of carbohydrates," he said. His diet initially restricts a lot of carbohydrates and sugars, even fruits, which leads to an 8- to 13-pound weight loss in the first two weeks. The key is to cut that afternoon craving that leads to junk food, he said. "The real purpose is to prevent cravings so you can lose weight without being hungry," which causes many diets to fail, Dr. Agatston said.

But the real impact is that those on the diet lose their appetite, an effect that could be compared to what a chemotherapy patient suffers, said John McDougall, an advisory board member to the Physicians Committee for Responsible Medicine, which advocates a low-fat, vegetarian approach to weight loss.

"I call it nausea," he said. The initial weight loss is from the body feeding off of 2 pounds of sugar and losing 4 pounds of water, he said.

Dr. Agatston admitted that some weight reduction is from  water loss, but, he added, "We've not seen any problems with that."

Carbs come back into the South Beach diet in the second phase, although it emphasizes getting carbs from foods less likely to cause blood-sugar spikes, or those with a low glycemic index. It is not like the low-carb Atkins diet because it does not force a patient's body to burn its own fat, a process called ketosis, Dr. Agatston said.

"We measured for ketosis, and we made sure our diet did not go into ketosis," he said. "And we don't believe in restricting all those important nutrients (from fruits and vegetables, as with Atkins)."

Getting good fats, particularly omega-3 fatty acids, and more fiber is just as important, but often isn't pushed in other approaches, Dr. Agatston said. In fact, although low-fat diets reduce the amount of bad cholesterol, LDL, they also reduce the amount of good cholesterol, HDL.

That can have an impact on heart disease, said Ward Rogers, of Augusta Cardiology Associates. "A low level of HDL increases your risk of coronary disease" regardless of what other cholesterol levels are, Dr. Rogers said.

The diet book's success - it topped The New York Times' nonfiction list - caught Dr. Agatston by surprise.

"I thought I could use it for the education of my patients," said the Miami Beach cardiologist. "I had no idea it would be anything like this."

Reach Tom Corwin at (706) 823-3213 or tom.corwin@augustachronicle.com.