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Showing posts with the label Atkins

All diets succeed at first, and eventually fail

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It is not very hard to find studies supporting one diet or another. Gardner and colleagues, for example, conducted a study in which the Atkins diet came out on top when compared with the Zone, Ornish, and LEARN diets ( ). In Dansinger and colleagues’ study ( ), on the other hand, following the Atkins diet led to relatively poor results compared with the Ornish, Weight Watchers, and Zone diets. Often the diets compared have different macronutrient ratios, which end up becoming the focus of the comparison. Many consider Sacks and colleagues’ conclusion, based on yet another diet comparison study ( ), to be the most consistent with the body of evidence as a whole: “Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize”. I think there is a different conclusion that is even more consistent with the body of evidence out there. This conclusion is highlighted by the findings of almost all diet studies where participants were followe...

What is a good low carbohydrate diet? It is a low calorie one

My interview with Jimmy Moore should be up on the day that this post becomes available. (I usually write my posts on weekends and schedule them for release at the beginning of the following weeks.) So the time is opportune for me to try to aswer this question: What is a good low carbohydrate diet? For me, and many people I know, the answer is: a low calorie one. What this means, in simple terms, is that a good low carbohydrate diet is one with plenty of seafood and organ meats in it, and also plenty of veggies. These are low carbohydrate foods that are also naturally low in calories. Conversely, a low carbohydrate diet of mostly beef and eggs would be a high calorie one. Seafood and organ meats provide essential fatty acids and are typically packed with nutrients. Because of that, they tend to be satiating. In fact, certain organ meats, such as beef liver, are so packed with nutrients that it is a good idea to limit their consumption. I suggest eating beef liver once or twice a we...

Ketones and Ketosis: Physiological and pathological forms

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Ketones are compounds that have a specific chemical structure. The figure below (from: Wikipedia) shows the chemical structure of various types of ketones. As you can see, all ketones share a carbonyl group; that is the “O=” part of their chemical structure. A carbonyl group is an oxygen atom double-bonded to a carbon atom. Technically speaking, many substances can be classified as ketones. Not all of these are involved in the same metabolic processes in humans. For example, fructose is technically a ketone, but it is not one of the three main ketones produced by humans from dietary macronutrients (discussed below), and is not metabolized in the same way as are those three main ketones. Humans, as well as most other vertebrates, produce three main ketones (also known as ketone bodies) from dietary macronutrients. These are acetone, acetoacetate and beta-hydroxybutyrate. Low carbohydrate diets tend to promote glycogen depletion, which in turn leads to increased production of th...

Long-term adherence to Dr. Kwaśniewski’s Optimal Diet: Healthy with high LDL cholesterol

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This is a study (Grieb, P. et al., 2008; full reference at the end of this post) that I read a few years ago, right after it came out, and at the time I recall thinking about the apparent contradiction between the positive effects of the Optimal Diet and the very elevated LDL cholesterol levels among the participants. I say “contradiction” because of the established and misguided dogma among medical doctors, particularly general practitioners, that decreasing LDL cholesterol levels is the best strategy to avoid cardiovascular disease. The Optimal Diet is one of the best examples of a healthy diet where LDL cholesterol levels are generally high, in fact much higher than most people are willing to accept as healthy today. (In this study, LDL cholesterol levels were calculated based on the Friedewald equation .) It is not uncommon to see people concerned about their high LDL cholesterol levels after adopting a low carbohydrate diet. (A low carbohydrate diet is, generally speaking, a high ...

Ketosis, methylglyoxal, and accelerated aging: Probably more fiction than fact

This is a follow up on this post . Just to recap, an interesting hypothesis has been around for quite some time about a possible negative effect of ketosis. This hypothesis argues that ketosis leads to the production of an organic compound called methylglyoxal, which is believed to be a powerful agent in the formation of advanced glycation endproducts (AGEs). In vitro research, and research with animals (e.g., mice and cows), indeed suggests negative short-term effects of increased ketosis-induced methylglyoxal production. These studies typically deal with what appears to be severe ketosis, not the mild type induced in healthy people by very low carbohydrate diets. However, the bulk of methylglyoxal is produced via glycolysis, a multi-step metabolic process that uses sugar to produce the body’s main energy currency – adenosine triphosphate (ATP). Ketosis is a state whereby ketones are used as a source of energy instead of glucose. (Ketones also provide an energy source that is distinct...

Want to improve your cholesterol profile? Replace refined carbs and sugars with saturated fat and cholesterol in your diet

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An interesting study by Clifton and colleagues (1998; full reference and link at the end of this post) looked at whether LDL cholesterol particle size distribution at baseline (i.e., beginning of the study) for various people was a determinant of lipid profile changes in each of two diets – one low and the other high in fat. This study highlights a few interesting points made in a previous post , which are largely unrelated to the main goal or findings of the study, but that are supported by side findings: - As one increases dietary cholesterol and fat consumption, particularly saturated fat, circulating HDL cholesterol increases significantly. This happens whether one is taking niacin or not, although niacin seems to help, possibly as an independent (not moderating) factor. Increasing serum vitamin D levels, which can be done through sunlight exposure and supplementation, are also known to increase circulating HDL cholesterol. - As one increases dietary cholesterol and fat consumption...

Half-hearted Atkins diet and cardiovascular disease

I would like to comment on a recent  article comparing the Atkins, Ornish and South Beach diets (Miller et al., 2009; full reference at the end of this posting), which has been causing quite a lot of commotion among bloggers recently. Especially low carb. bloggers. An excellent post by Michael Eades clarifies a number of issues with the study, including what one could argue is the study's main flaw. Apparently the study compared a half-hearted Atkins diet, with probably equally half-hearted Ornish and  South   Beach  diets. I refer to the study's Atkins diet as half-hearted because it seems to rely on a daily consumption of between 120 and 180 grams of carbohydrates. This is unlikely to lead to ketosis, the cornerstone of the Atkins diet, where the body uses ketone bodies (made from dietary as well as body fat) as a source of energy. As I see it, the main findings of the study were that the participants in the half-hearted Atkins diet, after a period of 4 we...