LA Times On Low Carb

http://www.latimes.com/health/la-he-carbs-20101220,0,6026869,print.story
Excerpts follow:

"Fat is not the problem," says Dr. Walter Willett, chairman of the department of nutrition at the Harvard School of Public Health. "If Americans could eliminate sugary beverages, potatoes, white bread, pasta, white rice and sugary snacks, we would wipe out almost all the problems we have with weight and diabetes and other metabolic diseases."

"Americans, on average, eat 250 to 300 grams of carbs a day, accounting for about 55% of their caloric intake. The most conservative recommendations say they should eat half that amount. Consumption of carbohydrates has increased over the years with the help of a 30-year-old, government-mandated message to cut fat.

"And the nation's levels of obesity, Type 2 diabetes and heart disease have risen. "The country's big low-fat message backfired," says Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard School of Public Health. "The overemphasis on reducing fat caused the consumption of carbohydrates and sugar in our diets to soar. That shift may be linked to the biggest health problems in America today."

"All carbohydrates (a category including sugars) convert to sugar in the blood, and the more refined the carbs are, the quicker the conversion goes. When you eat a glazed doughnut or a serving of mashed potatoes, it turns into blood sugar very quickly. To manage the blood sugar, the pancreas produces insulin, which moves sugar into cells, where it's stored as fuel in the form of glycogen.

"If you have a perfectly healthy metabolism, the system works beautifully, says Dr. Stephen Phinney, a nutritional biochemist and an emeritus professor of UC Davis who has studied carbohydrates for 30 years. "However, over time, as our bodies get tired of processing high loads of carbs, which evolution didn't prepare us for … how the body responds to insulin can change," he says.

When cells become more resistant to those insulin instructions, the pancreas needs to make more insulin to push the same amount of glucose into cells. As people become insulin resistant, carbs become a bigger challenge for the body. When the pancreas gets exhausted and can't produce enough insulin to keep up with the glucose in the blood, diabetes develops.

People are said to have (metabolic) syndrome when they have three or more of the following: high blood triglycerides (more than 150 mg); high blood pressure (over 135/85); central obesity (a waist circumference in men of more than 40 inches and in women, more than 35 inches); low HDL cholesterol (under 40 in men, under 50 in women); or elevated fasting glucose.

"Put these people on a low-carb diet and they'll not only lose weight, which always helps these conditions, but their blood levels will improve," Phinney says. In a 12-week study published in 2008, Phinney and his colleagues put 40 overweight or obese men and women with metabolic syndrome on a 1,500-calorie diet. Half went on a low-fat, high-carb diet. The others went on a low-carb, high-fat diet. The low-fat group consumed 12 grams of saturated fat a day out of a total of 40 grams of fat, while the low-carb group ate 36 grams of saturated fat a day — three times more — out of a total of 100 grams of fat.

"Despite all the extra saturated fat the low-carb group was getting, at the end of the 12 weeks, levels of triglycerides (which are risk factors for heart disease) had dropped by 50% in this group. Levels of good HDL cholesterol increased by 15%.

"In the low-fat, high-carb group, triglycerides dropped only 20% and there was no change in HDL.

"The good news," adds Willett, "is that based on what we know, almost everyone can avoid Type 2 diabetes. Avoiding unhealthy carbohydrates is an important part of that solution." For those who are newly diagnosed, he adds, a low-carb diet can take the load off the pancreas before it gets too damaged and improve the condition — reducing or averting the need for insulin or other diabetes meds.

"Carbohydrates are a metabolic bully," Phinney says. "They cut in front of fat as a fuel source and insist on being burned first. What isn't burned gets stored as fat, and doesn't come out of storage as long as carbs are available. And in the average American diet, they always are."

"When you cut carbs, your body first uses available glycogen as fuel. When that's gone, the body turns to fat and the pancreas gets a break. Blood sugar stabilizes, insulin levels drop, fat burns. That's why the diet works for diabetics and for weight loss.
Beyond the fat-burning effects of ketosis, people lose weight on low-carb diets because fat and protein increase satisfaction and reduce appetite.  "At my obesity clinic, my default diet for treating obesity, Type 2 diabetes and metabolic syndrome is a low-carb diet," says Dr. Eric Westman, director of the Lifestyle Medicine Clinic at Duke University Medical Center, and co-author of the new Atkins book. "If you take carbohydrates away, all these things get better."

"Dr. Ronald Krauss, senior scientist at Children's Hospital Oakland Research Institute and founder and past chair of the American Heart Assn.'s Council on Nutrition, Physical Activity and Metabolism, says those who eat too many calories tend to overconsume carbohydrates, particularly refined carbohydrates and sugars. "It can be extremely valuable to limit carbohydrate intake and substitute protein and fat. I am glad to see so many people in the medical community getting on board. But in general I don't recommend extreme dietary measures for promoting health."

Note:  I agree with Dr. Krauss, an extreme, fad diet like one high in grains and sugars, and low in protein and fat, is a disaster for human health, mentally and physically.