Low-Carb, High-Fat Diet Drops Weight

Atkins-Like Plan Won't Hurt Cholesterol Levels, but Critics Aren't Impressed

From the WebMD Archives

Nov. 11, 2003 -- Is it really possible to lose weight on a no-starch, high-fat diet, similar to Atkins, without hurting cholesterol levels? Apparently so, even for people with heart disease, according to the latest study on the topic.

The new study details the effects of a no-starch, high-fat diet on 23 patients at risk for diabetes. All were overweight, were taking cholesterol-lowering statin drugs, and had been diagnosed with heart disease. The high-saturated fat and no-starch diet was developed eight years ago by endocrinologist James Hays, MD, in an effort to help his diabetic patients.

On average, those following his low-carb, high-fat diet lost 5% of their body weight after only six weeks. For example, a 200-pound person would have lost 10 pounds.

Importantly, the high-fat diet did not have harmful effects on cholesterol levels. In fact, the participants saw a lowering of the blood fat called triglycerides. "Bad" LDL and "good" HDL cholesterol levels didn't change, but the size of the HDL and LDL molecules increased.

Larger LDL molecules are less likely to form artery-clogging plaques. Larger HDL molecules stay around in the body longer to clean up more plaque.

"We also saw a significant drop in glucose and insulin levels," Hays tells WebMD. Higher blood sugar (glucose) and insulin levels indicate the early signs of diabetes.

Lots of Fat Allowed

Under Hays' plan, half of the daily 1,800 calories come from saturated fats -- mostly red meats and cheese. "We're not talking about protein, egg whites, and turkey and white-meat chicken," he says. "We're talking about fat."

Just days ago, another study at the American Heart Association's annual meeting compared the low-carb, high-fat Atkins diet to three other popular diets -- the very low-fat Ornish plan, the high-protein, moderate-carb Zone diet, and the low-fat, moderate-carb Weight Watchers plan. When devotedly followed, all produced similar weight loss and reductions in heart disease risk.

Hays tells WebMD that he believes the heart-healthy benefits of his Atkins-like eating plan are because of its high intake of saturated fats -- considered by most experts to causeheart disease.

"Cholesterol leaves our body through bile, and high-fat foods cause bile secretion," he says. "Although I would caution that this is genetically determined, I think that most people are able to excrete huge amounts of cholesterol they're consuming with this bile secretion." Still, he advises that anyone starting any type of high-fat diet keep close tabs on their cholesterol and triglyceride levels.

Under Hay's low-carb, high-fat diet, milk and starches such as pasta and baked goods are forbidden and only certain fruits and vegetables can be eaten. And unlike Atkins, which allows for increased but still low amounts of carbohydrates the longer participants remain on the plan, Hays' plan remains constant.

A typical dinner on the Hays plan: "A half-pound of red meat or chicken dark meat (after cooking), with 1/2 cup of vegetables, 1/2 cup of salad, and a half piece of fruit. There's lots of oil but no vinegar or other condiments," he says. Acceptable vegetables include broccoli, cauliflower, and others that grow above ground; allowed fruits (which must be eaten last at every meal to keep glucose levels low) include apples, oranges, peaches, and pears, as long as they are not processed.

"It's very vigorous to eliminate starches completely, but those who do seem to do very well," Hays says. "We followed two other groups of patients who weren't taking statin medications for six months and a year, and they lost 15% and 20% of their body weight respectively and had no adverse effects on their [blood fats]. I've had some patients lose up to 40% of their weight on this plan."

But Is It Healthy?

Not all are convinced a high-fat diet is the best strategy for the long term.

"The main reason people lost weight on this diet is because they're consuming fewer calories than they're used to," says Jen Keller, RD, staff nutritionist for the Physicians Committee for Responsible Medicine, a nonprofit organization that promotes preventive medicine and a vegetarian diet.

"It doesn't matter how you lose weight -- you can starve yourself, you can eat eggs all day, however you do it, if you're eating fewer calories that you're used to, your blood fats will improve in the short-term," she tells WebMD. "But a lot of times, when the weight loss plateaus, the benefits in cholesterol are erased and you're no better off than when you started, and sometimes worse."

Her group has been a longtime and vocal critic of low-fiber, high-fat diets such as Atkins, and she is concerned that such eating plans raise the risk of colon cancer, kidney disease, and other health problems.

"A new study comes out every day talking about what's the best way to lose weight. If you look at the world's population, the healthiest and thinnest people are people who follow a plant-based diet," she says. "As they start to eat more fats, they gain weight and develop health problems."

In an accompanying editorial, Mayo Clinic cardiologist Gerald Gau, MD, urges doctors to keep an open mind about these high-fat diets. "But I am concerned about the long-term cardiovascular risk," he writes. "We should continue to examine the risk-benefit profile of caloric-restricted, more rational diets such as the Mediterranean diet, which recently was associated with a striking decrease in cardiovascular risk."

Show Sources

SOURCES: Hays, J. Mayo Clinic Proceedings, November 2003; vol 78: pp 1331-1336. Gau, G. Mayo Clinic Proceedings, November 2003; vol 78: pp 1329-1330. American Heart Association Scientific Sessions 2003, Orlando, Fla., Nov. 9-12, 2003. James Hays, MD, endocrinologist, Christiana Care Health Services, Cardiology Research, Newark, Del. Jen Keller, RD, staff nutritionist and nutrition projects coordinator, Physicians Committee for Responsible Medicine (PCRM), Washington, D.C.
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