Low carbohydrate, high-fat diets such as the Paleo, ketogenic and Atkins plans are significantly more effective for weight loss and preventing heart disease than low-fat diets, according to a new study published Sept. 2 in the Annals of Internal Medicine. The research bolsters similar recent reports indicating that carbohydrate (not calorie or fat) restriction is the key to weight loss.
Researchers at Tulane University tracked 148 obese men and women for one year. The subjects ranged in age from 22 to 75 and did not have heart disease or diabetes. The participants were divided into two groups: One group followed a low carb diet that limited their daily carbohydrate consumption to about 40 grams of digestible carbs, or about 28 percent of their daily calories.
The low-carb dieters consumed about 40 to 43 percent of their daily calories from fat. Their daily menu was similar to the Paleo, ketogenic and Atkins diets, and included eggs, butter, fish, chicken and some red meat, as well as generous portions of healthy fats such as olive oil. In contrast, the low-fat group consumed about 40 to 55 percent of their daily calories from carbohydrates, and their fat intake was limited to less than 30 percent.
Low Carb Dieters Lost 3 Times More Weight
The results were stunning: The low-carb dieters lost about 12 pounds, while the low-fat dieters lost 4 pounds even though both groups consumed the same calories.
What's more, the low carbohydrate dieters lost more body fat and scored better than on a test that measured their chances of suffering a heart attack or stroke within the next 10 years. Physician Dr. Lydia Bazzano, the lead study author, was surprised that a low-carb, high-fat diet could prevent heart disease better than a low fat diet, which has long been prescribed for heart patients.
The Tulane study confirms the results of research published last year in the Journal of the American Medical Association, which compared a low glycemic-index diet (which is similar to a low carb diet) to a low-fat diet. In that study, researchers at Harvard University found that subjects who limited their carb intake burned 150 more calories a day than low-fat dieters and experienced improved cholesterol readings and lower inflammation.
"We saw improvements in triglycerides, [good] cholesterol, and the possibility of lower chronic inflammation" in the lower-carb group, study author Dr. David Ludwig of Harvard Medical School told NPR. "Too much refined carbohydrates — white bread, white rice, potato products — all the foods that crept into our diets as we've followed the low-fat craze has undermined our metabolism."
High-Carb Diet Slows Metabolism, Fuels Inflammation
Ludwig said the key to weight loss is to follow low-carb, high-fat diets such as the Paleo, ketogenic or Atkins diets instead of the standard low-fat, high-carb diet that has been recommended for the past 40 years by medical and nutrition experts.
Ludwig, a physician, said the high-carb, low-fat standard American diet has caused us to get fat, ruined our metabolism and fueled inflammation, which is a key driver of heart disease, cancer, diabetes and other illnesses.
"[Low-fat, high-carb diets] caused us to become hungrier and burn off fewer calories," he said. "It's a double-whammy for weight gain. We've been told for decades that if you don't want fat on your body, don't put fat into your body. It's a very appealing notion, but the problem is it's wrong."
Low-carb diets accelerate weight loss by forcing the body to burn fat (instead of glucose) for fuel, said obesity expert Dr. Eric Westman, co-author of Keto Clarity.
Many celebrities have hopped on the low-carb bandwagon. Kim Kardashian famously lost 56 pounds on a low-carb ketogenic Atkins diet that limited her daily carb intake to less than 60 grams. Similarly, Megan Fox credited a low-carb Paleo diet for her stunning recent post-baby weight loss, and Tim McGraw lost 40 pounds and got rippling 8-pack abs (at age 47) after adopting a low-carb Paleo diet.
LCHF Ketogenic Diet Starves Cancer
In addition to their weight loss benefits, the low-carb, high-fat (LCHF) ketogenic and Paleo diets have been shown to prevent and starve cancer. Renowned cancer researcher Dr. Thomas Seyfried told me the ketogenic diet beats chemotherapy for most cancers.
“The ketogenic diet is a single metabolic approach to a multitude of different diseases,” said Dr. Seyfried. "The standard of care has been an abysmal failure for cancer. The ketogenic diet may one day replace the standard of care for most cancers.”
Seyfried's decades of research indicate cancer is a metabolic — not a genetic — disease. And his research shows the ketogenic diet effectively treats advanced cancer in mice.
These same anti-cancer properties have also been observed in human cancer patients and reported in published studies. Today, there are about a dozen studies that are investigating the use of the ketogenic diet to manage all kinds of cancer. Those results will determine whether the medical community will adopt diet therapy to treat cancer in the future.