More from The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable by Dr. Stephen Phinney and Dr. Jeff Volek: When looking at studies about high-fat diets, it is important to know what is meant by a high-fat diet. Most consensus experts define a high-fat diet to be one with 45% – 60% of calories from fat. The authors of the book define high-fat to be 65% – 85% of calories from fat. The distinction is very important. Consensus experts will tell you that insulin resistance gets worse as fat in the diet increases, and this is true of the diets in the lower range. However, after fat intake goes above 60% of calories from fat, insulin resistance turns around and starts to improve. The benefits of a low-carb diet are found in the higher range of fat intake.
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Who would think that we’d actually see a medical doctor post an entry on his blog called “Add lard to your larder”? Dr. Michael Eades, the author of Protein Power, did just that. Among interesting points that he made, he said that the Mediterraneans are actually eating lard more than olive oil. The olive oil they produce in the region is for export. That certainly changes the face of what many believe is one of the healthiest diets!
In another of his posts about “The best low-carb book in print,” he quotes study summaries from the book. One study was particularly interesting. They looked at an ADA low-fat/high-carb diet against a low-carb/high-fat diet. I like studies like this because it pits one intervention diet against another, thus eliminating the conscientiousness factor when comparing the diets. Even though the high-fat dieters were eating considerably more saturated fat, the blood levels of saturated fat decreased from their pre-diet numbers, both in terms of percentage of fat in the blood and in terms of the absolute serum content. By the latter measure, saturated fat in the blood dropped 30% in the high-fat group, even though they were eating more saturated fat. Triglycerides fell by 51% in this group. The latter figure did not surprise me much because I already knew that triglycerides increase with carb intake. It would have been nice to know how they did weight-wise, but Dr. Eades did not quote those results. I guess I’ll have to get the book to find out.
I’m currently reading about the Optimal Diet devised and implemented by Dr. Jan Kwasniewski. The Optimal Diet is a low-carb/high-fat diet that would meet fat intake criteria for epileptics. Testimonials on the Optimal Diet website claim that the diet reversed atherosclerosis, diabetes, ankylosing spondylitis, asthma, and multiple sclerosis, among others. I would caution, though, that the cured meats suggested in some of the menus should be avoided. Cured meats have been linked with some cancers. It is not surprising to me that some long-time adherents of the Optimal Diet have been coming down with digestive cancers, considering that cured meats are suggested to them. Natural meats are supposedly safe, from what I have heard.
I’ve read the main part of the theory behind Dr. Rosedale’s diet in his book and some of the practical application. What follows is my summary of that information.
Dr. Rosedale says that the body can burn fat or sugar, but it won’t burn both at the same time. He claims that a diet high in carbohydrates causes the body to get stuck in sugar burning mode. When there is too much sugar in the blood, the excess gets stored as saturated fat. That would be fine if we could then switch to fat burning mode and burn the fat when the sugar is used up. But that, Dr. Rosedale claims, is not what happens. As we get older, our ability to switch between sugar burning mode and fat burning mode diminishes. So when someone in sugar burning mode runs out of sugar to burn, his body cannibalizes the protein from its muscle and bone to make sugar to burn. The fat remains in the fat cells. This is why someone who loses weight on a typical low-fat/high-carb diet loses muscle and ends up being a smaller version of a fat person.
A low-carb/high-protein diet does not correct this problem since excess protein in the diet is converted into sugar, and that raises blood sugar, too, and the body ends up remaining in sugar burning mode. The body does not store protein, so the body still ends up cannibalizing muscle and bone when the supply of sugar and dietary protein runs out. When protein is converted to sugar, the nitrogen atoms are stripped from the protein in the form of urea and ammonia, and this becomes a toxic waste product that the body must deal with. So really, a diet that includes excess protein is toxic. Dr. Rosedale recommends getting 50 – 75 grams of protein from the diet, which is consistent with RDA recommendations.
So that leaves fat as a preferred source of fuel. But not all fats are healthy. Dr. Rosedale recommends getting fat from fish and fish oil, nuts and nut oils, avocados and avocado oil, olives and olive oil, and coconut oil. He recommends eating lean poultry, limited amounts of lean meat, and low-fat dairy from properly raised animals to avoid the saturated fat content. Properly raised animals means grass-fed or pasture-raised and animals raised without added hormones and antibiotics, not the CAFO animals typically sold in supermarkets. The diet also includes generous amounts of non-starchy vegetables and some berries.
As an aside, Dr. Rosedale did mention the link between depression and low-fat diets, which has been my primary contention against them and why I have increased the fat in my NutriSystem plan, having myself suffered from depression that I now believe was a result of low-fat dieting.
Dr. Rosedale also claims that his diet is de-aging. The low-carb content of his diet gives the life-extension benefits of a calorie-restricted diet without having to go hungry. In other words, he is claiming that his diet can reverse age-related degeneration. This is due to the low insulin and leptin levels maintained while on such a diet and the proper functioning of these hormones. Dr. Rosedale’s diet is a lifestyle diet. His list of benefits from his diet is quite long, and there isn’t space to list them all here.
The general theory behind Dr. Rosedale’s diet makes sense to me and agrees with my experience of dieting. I have lost weight on a high-fat diet before. I also believe that I have suffered harm from low-fat diets as Dr. Rosedale says we will, namely my worst depressions have coincided with stints of low-fat dieting. Dr. Rosedale’s theories also explain a lot about why we yo-yo and how fat can end up in the arteries, among other effects that can result from the derangement of insulin and leptin functioning. I’m not sure about Dr. Rosedale’s recommendation to minimize animal fat. I do agree that ideally the animals should be pasture-raised if one can afford to buy such since grain feeding alters the balance of the polyunsaturated oils from healthy omega-3 to harmful omega-6. But I also have been led to believe that animal fat contains important fat-soluble nutrients that are difficult to get from other sources. Therefore, meats and dairy should include their fats. My previous foray into veganism and subsequent detriment would support this conclusion.
I was surfing the web yesterday looking for information about Rabbit Starvation, the result of exclusively eating lean meat, when I came across information about the Rosedale Diet on the Ketogenic Diet Resource site. The Rosedale information talks about how the hormone leptin figures into aging and overweight. Science hasn’t known about leptin for very long. It wasn’t discovered until 1995. Leptin helps to control hunger and fat burning, among other things. Usually, when leptin is low, that signals hunger. When it goes up, that tells the body to burn fat. At least that’s how it’s supposed to work. Scientists thought when they first discovered leptin that the answer to obesity could be as simple as giving leptin supplements to obese people. But they found out that obese people tend to have very high levels of leptin already. They figured out that people can become leptin insensitive just as they can become insulin insensitive. Dr. Rosedale believes that overweight and obesity are the result of a derangement in the functioning of insulin and leptin. Overeating of carbohydrates can cause this derangement. Other materials I have read focused on the insulin alone, so this is a bit different. Dr. Rosedale determined that his low-carb/high-fat/controlled-protein diet can restore proper leptin functioning in the body. As he says, fat doesn’t make you fat; the inability to burn fat makes you fat. Restoring leptin function corrects the body’s ability to burn fat and thus allows the body to burn its stored fat. The result of weight lost this way is a trim, lean, muscular body and not just a thin version of a fat person. I decided to buy Dr. Rosedale’s book and learn more about how leptin functions since I haven’t seen much about it up until now.
There was an interesting dietary study done in 1931. They conducted a controlled dietary trial using a large variety of diets, ranging from 800 to 2,700 calories. Before they did that, they put all patients on a 1,000 calorie diet of varying types. Here are the stats for the average daily losses for the 1,000 calorie diets:
High-carbohydrate/low-fat – 49 grams
High-carbohydrate/low-protein – 122 grams
Low-carbohydrate/high-protein – 183 grams
Low-carbohydrate/high-fat – 205 grams
In other words, the patients on the low-carbohydrate/high-fat diet lost 4 times what those on the high-carbohydrate/low-fat diet lost. In another commentary on this diet, Barry Groves said that some patients actually gained weight on the high-carbohydrate/low-fat diet.
It was expected that on the 1,700 and 2,700 calorie diets, patients would not lose weight. In fact, all but three did lose weight.
In their conclusion, Lyon and Dunlop said: “The most striking feature … is that the losses appear to be inversely proportionate to the carbohydrate content of the food. Where the carbohydrate intake is low the rate of loss in weight is greater and conversely.”
Barry Groves says in Trick and Treat that the high-fat diet is preferable over the high-protein diet because excess protein creates waste products that stress the organs such as the kidneys. Fat burns cleaner in the body.
Lyon DM, Dunlop DM. The treatment of obesity: a comparison of the effects of diet and of thyroid extract. Quart J Med 1932; 1: 331.
Barry Groves. Trick And Treat – how ‘healthy eating’ is making us ill. 2008.
Barry Groves’ site: http://www.second-opinions.co.uk/
There was a study done in 1956 comparing weight loss on diets of differing macronutrient content. The diets were all 1,000 calories. One was 90% carbohydrate, another was 90% protein, another was 90% fat, with the last being a mixed diet. Those on the 90% fat diet lost the most weight, with those on the 90% protein diet coming in as a close second. Those on the 90% carbohydrate diet lost the least, and some of those even gained weight.
A. Kekwick M.A., M.B. Camb., F.R.C.P. , G.L.S. Pawan B.Sc. Lond. Calorie intake in relation to body-weight changes in the obese. The Lancet, Volume 268, Issue 6935, Pages 155 – 161, 28 July 1956.