Absolutely it is. Doctors won't tell you it is because they've been trained to tell you that. I had my blood drawn about 2 years after starting it. I would tell you the numbers but I seem to have lost them. Bottom line, my Total Cholesterol, Good Cholesterol, Bad Cholesterol and Triglycerides were all very solid numbers. You only do the no carb thing for two weeks, after that you find your own carb amount that will still allow you to lose weight. Or maintain it if that's what you're looking for. Bottom line, the less carbs you eat the more weight you'll lose. But even though 20g per day is kind of the magic number, cutting down from, say, 250 to 75 will still make a big difference . . . just not as big of a difference.