In this 12‑minute YouTube monologue, Dr. David Perlmutter reviews the 2007 Journal of the American Medical Association "A to Z" randomized trial, which compared four popular diets—Atkins, Ornish, Zone, and a traditional American diet—in 311 overweight, pre‑menopausal, non‑diabetic women over 12 months. He focuses on the two extreme diets, Atkins (high‑fat, low‑carb) and Ornish (low‑fat, high‑carb), contrasting their macronutrient profiles (Atkins 44% calories from fat, 34% carbs; Ornish the opposite). Perlmutter presents the trial’s quantitative outcomes: the Atkins group lost more weight (BMI ↓ 1.65), reduced body‑fat percentage (~3% vs. ~1.5% for Ornish), lowered triglycerides by ~30 mg/dL, raised HDL by ~5 mg/dL, and improved fasting glucose (↓ 2 mg/dL) and both systolic and diastolic blood pressure more than the Ornish group. LDL cholesterol fell only on the Ornish diet. He concludes that increasing healthy fats while dramatically cutting carbs yields superior weight loss and improvements in several cardiovascular and metabolic risk factors, challenging conventional low‑fat, high‑carb dietary recommendations.
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It seems like everybody wants to lose weight, and what is the best diet for weight loss? It is really a diet that, seemingly a paradox, is a diet that has the most fat. If you want to lose weight, you eat more fat. And this isn't really that new. This dates back to at least 2007, as published in the Journal of the American Medical Association. Let's have a look. So this is the famous A to Z study. It's a 12-month randomized trial of 311 overweight or obese, premenopausal, non-diabetic women, and again published in the Journal of the American Medical Association. And they looked at 4 different diets: the popular Atkins diet, which is really low carb; traditional American diet that we still hear recommendations for, which is a low-fat, high-carb diet; The Ornish Plan, which is a very high carbohydrate diet, and finally the Zone Diet, which is somewhat of a low carbohydrate diet. But for our purposes in this video, I'd like to just compare the Atkins Diet and the Ornish Diet because they represent the extremes. Atkins Diet gets 44% of its calories from fat, as opposed to a much significant reduction of carbohydrates down to 34%. And that's just exactly opposite pretty much of what the Ornish Plan recommends. As you will recall, the Ornish Diet is one that's low in fat and high in carbs. So let's compare the Atkins Program to the Ornish Program in terms of what the Journal of the American Medical Association has to say. Well, the Atkins Diet gives you a lot more saturated fat in terms of grams per day, 27 versus 17 for the Ornish Diet. Now the body mass index on the Atkins diet went down by 1.65. That's a measurement basically of how fat you are. On the Ornish diet, not anywhere near a significant reduction in comparison to the Atkins diet. The percentage body fat down by about 3% eating more fat and half that amount on the Ornish plan. Triglycerides, a powerful marker for risk for heart disease, Reduced by close to 30 points by eating more fat on the Atkins program, and about half that on the Ornish program that tells you to go on a low-fat diet. HDL, or good cholesterol, increases on the Atkins diet by about 5 points; no change on the low-fat Ornish program. LDL, or so-called bad cholesterol, goes down on the Ornish program for sure, and not much change on the Atkins program. What about fasting glucose, which we know is significantly related to risk for Alzheimer's disease? Down almost 2 points on the Atkins program and down by about less than 1 point on Ornish. Blood pressure goes down significantly eating more fat, and even the bottom number, the diastolic, goes down significantly more eating more fat on the Atkins program. And as you see here, the Atkins program is a diet that favors much more fat and a significant reduction in carbohydrate in comparison to what so-called US experts recommend, which is a diet that is much higher in carbohydrates. Published in the Journal of the American Medical Association, and this dates back to 2007, the A to Z trial, Clearly indicates that when we increase our consumption of good fat and dramatically reduce our consumption of carbohydrates, a variety of cardiovascular risk factors improve in favor of the high-fat diet, and you'll even lose more weight. I'm Dr. David Perlmutter.
