Low-carb diets like the Atkins, ketogenic and Paleo plans beat low-fat diets for producing weight loss and improving metabolism.
Scientists at the Obesity Prevention Center of Boston Children's Hospital said low-carb diets enhance weight loss by reducing inflammation (which fuels weight gain) and helping subjects burn more calories.
"We've found that, contrary to nutritional dogma, all calories are not created equal," said obesity expert Dr. David Ludwig, who led a recent study.
"Total calories burned plummeted by 300 calories on the low-fat diet compared to the low-carbohydrate diet, which would equal the number of calories typically burned in an hour of moderate-intensity physical activity."
Low-Carb Diets Stem Pro-Inflammatory Blood-Sugar Spikes
Ludwig, a physician, said low-carb diets are effective for weight loss because they reduce the surge in blood sugar after a meal. Spikes in blood sugar fuel inflammation, a key driver of both weight gain and chronic disease.
Ludwig and his team compared a low-fat diet (with a macronutrient ratio of 60 percent carbs, 20 percent fat, and 20 percent protein) with a low-glycemic index diet (40 percent carbs, 40 percent fat, and 20 percent protein), and a low-carb diet like Atkins (60 percent fat, 30 percent protein and 10 percent carbs).
Researchers found the low-carb diet was the best for weight loss and reducing inflammation, while the low-fat diet was the worst. These results confirm similar studies, which suggest LCHF diets like Atkins, ketogenic and Paleo can produce rapid weight loss without extreme calorie restriction or hunger.
This revelation isn't surprising to Dr. William Lagakos, author of The poor, misunderstood calorie. "The calories in food are not the same as those expended by the body," wrote Dr. Lagakos, who has a Ph.D. in nutritional biochemistry and physiology.
"Carb-rich foods are easily over-eaten, producing a positive energy balance. The accompanying elevations in insulin cause net fat storage. Maybe all calories are calories, but not all calories are equally obesogenic."
Carb Restriction Is the Silver Bullet for Managing Metabolic Syndrome
Dr. Jeff Volek, a pioneer in the low-carb, high-fat movement and professor at the University of Connecticut, agrees. What fuels weight gain and disease is inflammation — which is caused by a high-carb diet — especially one high in sugar, Volek told me.
Dr. Volek, author of The Art and Science of Low-Carbohydrate Living, explained that by drastically reducing carbs in our diet and replacing them with healthy, unprocessed fats, we boost fat-burning, eliminate nagging carb cravings, experience more stable blood sugar levels, and enjoy better mood.
Carbohydrate restriction is the proverbial ‘silver bullet’ for managing insulin resistance, metabolic syndrome, and type 2 diabetes. The medical profession continues to recommend a high-carb diet, which exacerbates the problem. It boggles the mind."
When we restrict carbs, we force our bodies to burn fat as fuel, which is why low-carb diets such as the Atkins, Paleo and ketogenic diets have proven effective for weight loss, said Volek, a registered dietician who has a Ph.D. in kinesiology.
Because dietary fat has a negligible impact on insulin, eating it doesn't produce surges in our blood glucose and blood insulin the way ingesting carbs does. More importantly, we don't fuel inflammation in our bodies, which causes aging and leads to obesity, heart disease, diabetes and Alzheimer's.
And because fat is more satiating than carbs — or even protein — you don't feel deprived on low-carb high-fat Atkins, Paleo or ketogenic diets the way you do on a low-fat diet, said Volek, author of New Atkins for a New You.
Low-carb diets have also become increasingly popular with celebrities. Kim Kardashian credited a LCHF ketogenic-style Atkins diet for her 56-pound weight loss in six months. Similarly, Sharon Osbourne lost 30 pounds with the LCHF Atkins plan, Linda O'Byrne, Atkins chief nutritionist, told me.
And country superstar Tim McGraw lost 40 pounds by following a low-carb Paleo diet and doing CrossFit workouts. McGraw now has the body of an athlete, and has rippling 8-packs for the first time in his life — at age 47. Even he is stunned by his transformation. "I was looking at some old concert shots the other day. Man, my gut!" he laughed.