The Ketogenic Diet

This is a review of Lyle McDonald’s The Ketogenic Diet: A complete guide for the Dieter and Practitioner. I’ve also recently read a couple of his other books, but after thinking about it a while, I learned the most from this one.

I’ve had this sitting around for a while, and I didn’t read it because I figured that 1) I wasn’t interested in a ketogenic diet at the moment and 2) I know what a ketogenic diet is already. The thing is that the book is chock full of biochemistry that I didn’t know and that was very enlightening.

Because of all the information it contains on everything related to metabolism, I’d recommend it for any non-scientist with a stubborn weight problem or really, any weight problem at all. No matter what kind of weight-loss diet you want to do, the processes detailed and explained in this book are really important to understand.

I also have a keen interest in his book The Rapid Fat Loss Handbook, but I’m not going to talk about that until Dr. Mike’s Thin So Fast shows up. It’s my understanding that it’s also a Protein Sparing Modified Fast, which is what the McDonald’s RFL Diet actually is. Anyway, moving on.

In case you don’t know what a ketogenic diet is, here’s a definition:

In the most general terms, a ketogenic diet is any diet that causes ketone bodies to be produced by the liver, shifting the body’s metabolism away from glucose and towards fat utilization. More specifically, a ketogenic diet is one that restricts carbohydrates below a certain level (generally 100 grams per day), inducing a series of adaptations to take place. Protein and fat intake are variable, depending on the goal of the dieter. However, the ultimate determinant of whether a diet is ketogenic or not is the presence (or absence) of carbohydrates.

Atkins is a ketogenic diet, as are most low-carb plans. There’s a lot of misunderstanding about what ketosis is, and instead of defending it, I’m just going to say that it IS NOT KETOACIDOSIS. This is well covered by McDonald – most people cannot provoke ketoacidosis since people without diabetes that are not alcoholics have feedback loops that prevent it ever happening. If you could cause this to happen just by not eating carbohydrates, how on earth would our human ancestors have made it through the ice age? Answer: they wouldn’t. Your system will deal, so don’t worry about it.

I now understand exactly how the brain starts using ketones for fuel, why it causes fatty tissue breakdown, and how much is too much protein on a low-carb diet. More importantly, I also understand how dietary fat works, and I see why I didn’t lose weight by shifting to a high-fat, low-carb diet. I’d get into ketosis, but it was mostly from dietary fat, so it never really touched my own stores. You can still eat fat and get your body to break down it’s own fat, but not too much.

Another really important thing: I understand why stalls happen on low-carb diets. The same hormones that caused your weight to drop are only made even MORE fat sparing by cutting carbs more – the usual solution. There are a lot of questions from people on the internet wondering how on earth they could be eating 20 carbs a day and not losing weight. The answer? They need to do a re-feed because their system has freaked out and lowered their metabolism by using hormones that are not insulin. It’s much easier for women to provoke this condition with a long-term very low-carb diet, but it can happen to men too. It’s more complex than this, but I’m not going to quote a whole chapter here.

One of things about protein that I learned that’s easy to explain is that it’s about 58% non-ketogenic. Let’s say I’m eating 125g of protein and 75g of net carbohydrate (we can ignore fiber here). This means that I will have 147g of glucose available for my body as fuel. This will definitely not be ketogenic. If I keep protein the same and lower net carbs to 50g, I should get into ketosis. The other factor is fat: about 10% of fat grams are made available as glucose in your bloodstream. Fat is *not quite* too cheap to meter, and eating more fat will actually lower utilization from your fat stores. If you’re trying to lose fat, that’s not something you want to do.

One of the other stumbling blocks for low-carb eaters is this one:

Individuals who have been on a low-carbohydrate diet (of any type) will show a rapid increase in bodyweight when carbohydrates are added to the diet (2,3). This weight gain…can be anywhere from 5 to 11 pounds (2,3).

For dieters who focus only on the scale, this rapid weight gain can be disheartening, pushing them straight back into a low-carbohydrate eating style. The inability to differentiate between weight gain and fat gain tends to promote the belief in dieters that excess carbohydrates (rather than excess calories) are the cause of their problems. This may make it difficult for these individuals to ever wean themselves away from the ketogenic diet.

For people who read AND FOLLOW the official Atkins Diet, they know to re-introduce carbs slowly. Most people just stop cold and add carbs back, gaining weight and then saying the diet failed them. In reality, they didn’t follow the diet.

The vital bit that McDonald suggests is this one: “for every 2 grams of carbohydrate which are added to the diet, 1 gram of fat must be removed.” This is because calories DO matter. How much you use and how much you waste has to do with your metabolism, but eating too many calories is going to cause you to gain weight over time. When you first stop dieting, your metabolism is often quite keen to put that fat right back on, so maintenance shouldn’t be ignored. McDonald recommends around a 65% fat diet, so it shouldn’t be too painful to remove some of that to add back carbs.

I don’t agree with everything last he says, but the science is understandable and well-referenced.

This book is very much worth reading, especially for Paleo/Primal types that are looking to lose (more) weight or lean out. I’m very well read in terms of diet books of the Paleo and low-carb stripe, and I learned a ton from this book. Yes, it’s expensive, so I’ll leave it to you if it’s worth it, but if you’re really stuck, it’s probably worth the $50.