jump to navigation

AND SUDDENLY, DR ATKINS IS PROVED CORRECT, YET AGAIN, FOLKS August 2, 2011

Posted by ADAM PARTNERS in Atkins Diet, DIETRY GUIDELINES FOR AMERICANS, Dr Atkins, High Fat Low Carb Diet, Obesity.
Tags: , , , , , , , ,
add a comment
Railroad tank car transporting high fructose c...

Railroad tank car transporting high fructose corn syrup.

Results from a new study show that adults who consumed 25% of their daily calories as fructose or high-fructose corn syrup beverages (a percentage within current government guidelines) for 2 weeks experienced increases in serum levels of cholesterol and triglycerides, to prove Dr Atkins true on his account that sugar consumption was directly linked to high cholesterol.

The authors of the study, recently accepted for publication in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolismand slated to be published in the October 2011 print issue, say the results should spur the government to reevaluate the guidelines.

Senior author Kimber Stanhope, PhD, from the departments of nutrition and molecular biosciences, University of California, Davis, and colleagues say the study was conducted to help sort out a discrepancy in 2 prominent sets of recommendations: The Dietary Guidelines for Americans, jointly published by the US Department of Health and Human Services and the US Department of Agriculture, recommend that people consume a maximum of 25% of their daily calories as added sugars. In contrast, the American Heart Association recommends an upper limit of 5%.

“While there is evidence that people who consume sugar are more likely to have heart disease or diabetes, it is controversial as to whether high sugar diets may actually promote these diseases, and dietary guidelines are conflicting,” remarked Dr. Stanhope in a press release.

To shed light on the effects of the higher government-recommended threshold, the researchers had 48 overweight and normal-weight adults (age, 18-40 years; body mass index, 18-35 kg/m2) consume beverages that contained fructose, high-fructose corn syrup, or glucose at the 25% upper limit for calorie intake for 2 weeks.

During the first 3.5 days of the trial, the participants stayed at an inpatient facility for baseline testing while consuming a balanced diet consisting of 55% complex carbohydrates. The following 12 days were at home on an ad libitum diet with the addition of 3 daily drinks of glucose-, fructose-, or high-fructose corn syrup-sweetened beverages (n = 16/group) that provided 25% of their energy requirements. The last 3.5 days were spent back at the inpatient facility for repeated testing while the participants were consuming energy-balanced diets containing 25% sugar-sweetened beverages and 30% complex carbohydrate.

At the end of the study period, participants who consumed fructose or high-fructose corn syrup in their drinks exhibited elevated blood levels of low-density lipoprotein (LDL) cholesterol, triglycerides, and apolipoprotein B (apo B).

Participants who consumed glucose in their beverages exhibited no such changes. More specifically, the 24-hour triglyceride area under the curve (AUC) increased compared with baseline during consumption of fructose (increase, 4.7 ± 1.2 mmol/L x 24 hours; = .0032) and high-fructose corn syrup (increase, 1.8 ± 1.4 mmol/L x 24 hours; = .035), but not glucose (decrease, 1.9 ± 0.9 mmol/L x 24 hours; = .14). Similarly, fasting LDL and apoB concentrations were increased during consumption of fructose (LDL increase, 0.29 ± 0.082 mmol/L; = .0023; apoB increase, 0.093 ± 0.022 g/L; = .0005) and high-fructose corn syrup (LDL increase, 0.42 ± 0.11 mmol/L; < .0001; apoB, 0.12 ± 0.031 g/L; < .0001), but not glucose (LDL increase, 0.012 ± 0.071 mmol/L, P= .86; apoB increase, 0.0097 ± 0.019 g/L; = .91).

One limitation is the lack of inclusion of sucrose in the study.

“There is growing evidence linking increases of postprandial triglyceride concentrations with proatherogenic conditions,” Dr. Stanhope and her colleagues explain. Their results add to this existing evidence, even in young adults. “It is [also] important to note,” write the authors, “that for both the current and [a] previous study [by our research group], the differential effects of fructose and [high-fructose corn syrup] compared to complex carbohydrate on the 24-h [triglyceride] profile were most marked in the late evening, approximately 4 and 6 hours after dinner. Studies investigating the relationship between this late-evening peak and proatherogenic changes would be of interest, as would investigations into the sources of the [triglycerides] that contributes to these peaks,” such as diet or fatty acids derived from adipose lipolysis.

According to the researchers, survey data suggest that 13% of the US population consumes 25% or more of their calories from added sugar. The current data provide evidence that this level of sugar consumption in young, healthy, normal, and overweight adults contributes to dyslipidemia after only 2 weeks and contradicts conclusions from recent reviews suggesting that “sugar intakes as high as 25-50% of energy have no adverse long-term effects” in terms of the metabolic syndrome, and “that fructose consumption up to 140 grams/day does not result in a biologically relevant increase of fasting or postprandial [triglycerides] in healthy, normal weight or overweight or obese” individuals.

Furthermore, the researchers conclude, their findings indicate the need for the government to reconsider its recommendations that include a maximal upper limit of 25% of total energy requirements from added sugar.

The study was supported by the National Heart, Lung and Blood Institute and by the National Center for Research Resources, both of the National Institutes of Health. One author has consulted for Denka Seiken Company and for Otsuka Pharmaceutical Company, Ltd, both in Tokyo, Japan. Another author is currently employed by Denka Seiken Co., and a third was formerly employed by this same company. Dr. Stanhope and the remaining 8 authors have disclosed no relevant financial relationships.


Advertisements

Partially Hydrogenated Oils July 30, 2011

Posted by ADAM PARTNERS in High Fat Low Carb Diet.
add a comment

Metabolic Poisons:

What’s Wrong with Partially Hydrogenated Oils?

Summary

Consuming partially hydrogenated oils is like inhaling cigarette smoke. They will kill you — slowly, over time, but as surely as you breathe. And in the meantime, they will make you fat!

 

Contents

Why Fats are Important

What is Hydrogenation?

What’s Wrong with Hydrogenation?

Partially Hydrogenated Oils Make You Fat!

You Eat More

Your Metabolism Slows

Avoiding Hydrogenation

Deep-Fried Foods: The Ultimate Killer

What You Can Do

The Legal Outlook

Epilog, 2009: Food Industry Sneaks Trans Fats Back In

The Bigger Picture

Resources

Metabolic Poisons:
What’s Wrong with Partially Hydrogenated Oils?

Summary
Consuming partially hydrogenated oils is like inhaling cigarette smoke. They will kill you — slowly, over time, but as surely as you breathe. And in the meantime, they will make you fat!
[1700 words]

Why Fats are Important

The first thing to understand about fats is that the essential fatty acids they contain are truly essential. They are the “active ingredient” in every bodily process you can name:

  • brain cell function and nervous system activity
  • hormones and intra-cellular messengers
  • glandular function and immune system operation
  • hemoglobin oxygen-transport system
  • cell wall function:
    • passing oxygen into the cell
    • passing nutrients into the cell
    • keeping foreign bodies out of the cell
  • digestive-tract operation
    • assimilating nutrients
    • blocking out allergens

In short, the essential fatty acids (contained mostly in polyunsaturated oils) are the most important nutrients there are — more important than vitamins, minerals, or even proteins. Because, without them, there is no life. They are the substance and foundation of life energy.

What is Hydrogenation?

Hydrogenation is the process of heating an oil and passing hydrogen bubbles through it. The fatty acids in the oil then acquire some of the hydrogen, which makes it more dense. If you fully hydrogenate, you create a solid (a fat) out of the oil. But if you stop part way, you a semi-solid partially hydrogenated oil that has a consistency like butter, only it’s a lot cheaper.

Because of that consistency, and because it is cheap, it is a big favorite as a butter-substitute among “food” producers. It gives their products a richer flavor and texture, but doesn’t cost near as much as it would to add butter.

Note:
Until the 1970’s, food producers used coconut oil to get that buttery flavor and texture. The American obesity epidemic began when it was replaced with partially hydrogenated vegetable oil — most often soybean oil. For more information, see Coconut Oil and Palm Kernel Oil: Miracle Medicine and Diet Pill.

What’s Wrong with Hydrogenation?

Unlike butter or virgin coconut oil, hydrogenated oils contain high levels of trans fats. A trans fat is an otherwise normal fatty acid that has been “transmogrified”, by high-heat processing of a free oil. The fatty acids can be double-linked, cross-linked, bond-shifted, twisted, or messed up in a variety of other ways.

The problem with trans fats is that while the “business end” (the chemically active part) is messed up, the “anchor end” (the part that is attached to the cell wall) is unchanged. So they take up their position in the cell wall, like a guard on the fortress wall. But like a bad guard, they don’t do their job! They let foreign invaders pass unchallenged, and they stop supplies at the gates instead of letting them in.

In short, trans fats are poisons, just like arsenic or cyanide. They interfere with the metabolic processes of life by taking the place of a natural substance that performs a critical function. And that is the definition of a poison. Your body has no defense against them, because they never even existed in our two billion years of evolution — so we’ve never had the need or the opportunity to evolve a defense against them.

But the worst part is that in the last stages of oil processing (or “refining”), the oil is literally steam distilled to remove its odor. So it doesn’t smell. But a hydrogenated oil is much worse than rancid butter. So it it did smell, it would smell worse than the most rancid butter you’ve ever seen. (And that goes for all refined oils, not just the hydrogenated ones. It’s just that hydrogenated oils are everywhere in the American diet.) So the next time you see “partially hydrogenated oil” on a label, think “rancid butter”.

Partially Hydrogenated Oils Make You Fat!

Partially hydrogenated oils will not only kill you in the long term by producing diseases like multiple sclerosis and allergies that lead to arthritis, but in the meantime they will make you fat!

You Eat More

It’s not like you have any choice in the matter. Remember that the essential fatty acids are vital to every metabolic function in your body. You will get the quantity of essential fatty acids that you need to sustain life, no matter what. You will not stop being hungry until you do.

If you are consuming lots of saturated fats, you really have no choice but to become fat, because saturated fats contain only small quantities of the polyunsaturated fats that contain the essential fatty acids you need. The key to being thin, then, is to consume foods containing large amounts of polyunsaturated oils. (Those foods include fish, olives, nuts, and egg yolks.) Over the long term, those foods remove your sense of hunger.

Note:
The difference between a “fat” and an “oil” is temperature. A “fat” is a lipid that is solid at room temperature. An “oil” is one that is liquid at room temperature. Both are lipids (or “oil/fat”). Change the temperature, and you can convert an oil into a fat, or vice versa.

Partially hydrogenated oils make you gain weight the same way that saturated fats do — by making you consume even more fat to get the the essential fatty acids you need. But partially hydrogenated fats are even worse. Not only do they produce disease over the long term, but they interfere with the body’s ability to ingest and utilize the good fats!

Picture it like this. The trans fats are now the guards along the watchtower. The essential fatty acids (the support troops) are waiting outside to get into the fort (the cell), so they can be distributed along the watchtower (the cell wall). But the guards won’t let them in! So they have to find someplace to stay in town. Over time, more and more troops are finding lodging in town. So new houses (fat cells) have to built to keep them in. The town grows more and more swelled with troops (fat), and it gets bigger and bigger (fatter). It’s not a pretty picture at all, when you realize that the town is your belly, buns, face, and neck.

Your Metabolism Slows

Worse, most partially hydrogenated oil is partially hydrogenated soybean oil. That’s a problem, because soybean oil depresses the thyroid–which lowers your energy levels, makes you feel less like exercising, and generally makes you fatter!

Of course, soybeans have been used for centuries in the Orient–but mostly as the basis for soy sauce and tofu. Asians didn’t have soy milk, soy burgers, soy this and soy that. Most of all, they never used concentrated essence of soybean, in the form of soybean oil. And they didn’t hydrogenate it, and they didn’t use it in everything.

Walking down supermarket aisles in America, you find product after product with partially hydrogenated oil–often in products you would never expect. But why not? After all, it’s cheaper than butter. And it’s not illegal. Yet. When you eat out, restaurant breads and fried foods are loaded with stuff.

As a result, Americans are consuming soybean oil–partially hydrogenated soybean oil–in virtually everything they eat. It’s no wonder that America is experiencing epidemic levels of diabetes, obesitiy, heart disease, and cancer.

Avoiding Hydrogenation

When you start reading food labels, it is astonishing how many products you will find that contain partially hydrogenated oils. In the chips aisle, there are maybe two brands that don’t: Lay’s Classic Potato Chips (not their other brands), and Laura Scudders chips. Most every other package on the shelf does.

Then there are the cookies and crackers. Most every single one does. About the only cookie that doesn’t is Paul Neuman’s fig newtons. Among peanut butters, the all-natural brands (Adams and Laura Scudders) don’t. All the rest seem to.

Even some items on the “health food” shelf, like Tigers Milk bars, contain partially hydrogenated oils. Can you imagine that?? A product marketed as a “health food” that contains partially hydrogenated oils? If they want to market it as a candy bar, fine. Caveat emptor. But to market it as a health food calls for a class action lawsuit on the basis of false advertising.

The more labels you read, the more astonished you will be at the variety and number of places that this insidious little killer shows up. Do read the labels. Do recoil in disgust, and do throw the product back on the shelf — or throw it on the floor, where it belongs.

And it’s not just partially hydrogenated oils, anymore…
When I first wrote this article in 1998, I asked myself, “What’s going to happen when consumers begin to become aware of the dangers of partially hydrogenated oils? Are manufacturers going to stop using it? I figured that the answer, unfortunately, would be “No”. They would probably just give it a new name. Well, it appears that the worst may have come to pass. Alert readers Robin Jutras, Gerard Lally, and ___ clued me in to the fact that manufacturers are now using mono- and di-glycerides–which are also hydrogenated oil products.

Deep-Fried Foods: The Ultimate Killer

Fortunately, this information is beginning to penetrate the public consciousness. Recently, a news special covered the subject. The reporter got some of the details wrong, but the general message was right on the money. And the one surprising tidbit of information in the report was the fact that most of the deep-fried foods served in fast food joints are fried in partially hydrogenated oils!

Now, deep frying all by itself is pretty bad. After all, you are applying a lot of heat. But if that heat is applied to a saturated fat, there is a limit to how much harm it can do. A saturated fat doesn’t have a “business end”. There is no part of it that is chemically active. It’s inert. Your body can burn it for fuel, but it can’t use it to carry out any of your metabolic processes.

But because a saturated fat is inert, it can’t be hurt much by heat. It’s not all that good for you, but it’s not terrible either. So if you’re going to fry, fry in a fully saturated fat like lard, or coconut oil. Or, use butter, which consists mostly of short-chain saturated fats that are easily burned for fuel, plus conjugated linoleic acid (CLA) which improves health (Bruce Fife, Detox, 68). And butter tastes great. It’s so good, in fact, that you don’t even need to use very much to get a lot of flavor. So at home you can fry with butter to get gourmet-quality food that is also healthy.

Even better, you could fry with coconut oil — which consists of medium chain fatty acids that contain 2/3’s the calories of long-chain saturated fats. They’re also metabolized differently, so they’re burned for energy instead of being stored as fat. And if that’s not enough, 50% of coconut oil consists of lauric acid, a medium-chain fatty acid that’s anti-bacterial, anti-viral, anti-fungus, and anti-yeast. (For more information, see Coconut Oil and Palm Kernel Oil: Miracle Medicine and Diet Pill.)

For commercial deep frying, though, butter is prohibitively expensive. Things were better when foods were fried in beef tallow and coconut oil, because they had a lot of flavor and the saturated fats aren’t harmed by the heat. But all that saturated fat sounds bad, so restaurants switched to partially hydrogenated vegetable oils. One “healthy” Mexican restaurant even advertised that they fried in vegetable oil. That would be somewhat better than partially hydrogenated oil — assuming that they weren’t using partially hydrogenated vegetable oil in the the first place — but subjecting the unsaturated fatty acids contained in a vegetable oil to the high heat of a deep frying vat is deadly, especially when the oil is used and reused all day long. The result would be the same kind of trans fats that you get in the hydrogenation process!

But the absolute worst commercial frying is done by the fast-food chains, who almost uniformly do their deep frying in cheap, deadly partially hydrogenated oil. Any fats that escaped being transmogrified in the hydrogenation process are now subjected to the deep frying process. It’s a miracle that any of the unsaturated fats escape being transmogrified, if any of them do.

What You Can Do

For starters, read food labels and avoid anything that contains the words “hydrogenated”. That means partially hydrogenated oils, hydrogenated oils, or anything of that kind (and mono-diglycerides, as well).

Note:
In 2006, a new FDA regulation takes effect that requires manufacturers to list the amount of trans fats on their product labels. Much as I would like to tell you that you can simply look for “0% trans fats” on the label, it would be useless for you to do so. The FDA wanted to put the words, “Warning: Trans fats may be dangerous to your health” on the labels–the same warning that first appeared on cigarettes–but the industry wouldn’t let them. And the way the labeling law works, the product can contain a significant percentage of trans fat, and still claim “0%”. Simply put, the labeling law is nearly useless. For more information, see What’s Wrong with Trans Fat Labels?

When eating out, avoid deep-fried foods at all costs, and pretend you’re allergic to wheat. (You probably are! Something like 50% of the population is. See What’s Wrong with Wheat?) And when you avoid wheat you stay away from both partially hydrogenated oils and high fructose corn syrup–another deadly ingredient in the American food supply that is rarely used in other countries–except where American corporations are involved.

If you follow those steps, you will do a good job of protecting yourself. But there is a simple thing you can do to help protect others, as well:

When you see a food that contains partially hydrogenated oils (especially if it claims to be healthy), put it back on the shelf upside down and backwards. (Sometimes it’s impossible to put things back upside down, so at least put them on the shelf backwards.)

To find out why this is an effective boycott strategy, see How to Carry Out an Effective Consumer Boycott.

The Legal Outlook

With any luck, the first lawsuits against “food” producers will begin in the next 10-20 years. The scientific knowledge has been available since the early 1990’s, at least, so there is no doubt they are fully aware of what they are doing. They have been ignoring the health effects for the sake of profit. Such behavior is both unethical and immoral. With luck, some day it will be illegal, as well.

Note:
When I originally wrote this article in 1998, I feared that as soon as the public became educated as to its danger, corporations would simply change the name of the substance or find something equally dangerous to replace it with. Fortunately, the FDA required labeling of trans fats, rather than partially hydrogenated oils. That forestalled the inevitable name change. But corporations have indeed found another process–one that may or may not be safer. To find out more, read What’s Wrong with Interesterified Oils?

Epilog, 2009: Food Industry Sneaks Trans Fats Back In

Once the FDA started requiring trans fats to be listed on the label, I thought that we were finally home free. Unfortunately, it turns out that the food industry has other options. Mono- and Di-Glyceridesare designated as “emulsifiers” rather than fats, so the trans fats they contain “don’t count”. (Until you ingest them.)

The Bigger Picture

As described in What’s Wrong with American Foods?, there is more than one thing wrong with the American food supply. It is a sad fact that American corporations put profit above all other considerations–above morality, above truth, above your health. They don’t regulate themselves, they’re not held in check by government, and the fiction that they are regulated by “the market” is, quite simply, a lie. That problem, and the only possible solution, is described more fully in What’s Wrong with American Corporations?. It’s a problem we must solve, for the sake of our children’s health, if for no other reason.

Resources

Other TreeLight articles:

Books:

Other resources:

Partially Hydrogenated Oils.

Food for Memory and Concentration – 3 Memory Foods that help students concentrate ~ Smart Study Guide for Better Grades July 30, 2011

Posted by ADAM PARTNERS in High Fat Low Carb Diet.
add a comment

Food for Memory and Concentration – 3 Memory Foods that help students concentrate A healthy, iron-rich breakfast early in the morning is the best food for memory and concentration. It keeps you alert all day long and gets you through the mental and physical rigors of school and college.Apart from this, there are three foods that when consumed regularly, are proven to increase brain power, memory, study retention and better performance in tests and exams.These are: Fish – They contain omega-3 fatty acids which is great for your hair as well as the grey cells. Cranberries – They contain vital antioxidants that help in boosting memory function. Egg yolk – Rich in choline, egg yolks are important for optimum brain health and hence, superior concentration.

via Food for Memory and Concentration – 3 Memory Foods that help students concentrate ~ Smart Study Guide for Better Grades.

High-Fat Diets Won’t Harden Arteries Low-carbohydrate diets that require patients to fill up on fats won’t lead to harder arteries, researchers say June 3, 2011

Posted by ADAM PARTNERS in High Fat Low Carb Diet, Obesity.
add a comment

Those who lost 10 pounds after curbing their carb intake had no differences in arterial stiffness than those on a more traditional, low-fat diet, Dr. Kerry Stewart of Johns Hopkins and colleagues reported at the American College of Sports Medicine meeting in Denver. “Losing weight may be more important to [arterial] health than the diet you’re on,” Stewart said. Some researchers have raised concerns that replacing carbs with fats may have adverse effects on blood vessels, especially since promoting consumption of fats runs “counter to what the public has been told [about reducing fat intake] for the last 20 or so years,” Stewart said. Yet studies have shown that a low-carb diet can have positive effects on blood pressure, cholesterol, and other parameters that may reduce the risk of the artery disease atherosclerosis and subsequent heart disease. So to assess what the diets are actually doing to patients’ arteries, Stewart and colleagues enrolled 55 overweight or obese but healthy patients ages 30 to 65 in a lifestyle modification program. None had heart disease or other markers of cardiovascular risk at enrollment. In addition to a supervised exercise program — an hour-long regimen three days per week — patients were randomized to either a low-carb or low-fat diet for six months. The researchers monitored arterial stiffness and other measures of blood vessel health. For this analysis, the researchers had data on 23 of 28 patients who lost 10 pounds on the low-carb diet, and 23 of 27 who did so on the traditional diet. Those on the low-carb diet lost the 10 pounds sooner than the low-fat group did — just 45 days instead of 70 days. There were no changes in arterial stiffness or endothelial function in either diet group, and that didn’t change after the results were adjusted for the time it took to shed 10 pounds, Stewart said. “My theory is that if people can achieve weight loss, it will benefit vasculature in every other system of body,” he told “Weight loss, in the long run, will count more than the specific content of the diet.” Nor were there any acute effects on vascular function after a lone high-fat meal, the researchers found. In a companion study, 66 patients had no changes in endothelial function after eating a 900-calorie, 50-grams-of-fat meal from McDonald’s. In fact, arterial stiffness significantly improved by 16 percent after that feast, the researchers found. “It really seemed to make the arteries relax more, but we’re not entirely sure how,” Stewart said. “We’ll have to look more deeply into that.” Some researchers contacted for outside comment said longer-term follow up may be needed to confirm those benefits. And analyses of the diet study that include the type of fats eaten would be helpful, they said. “It would be nice to know what the fat consisted of, as some may be safer than others — i.e. monounsaturated fats and omega-3 fatty acids and even polyunsaturated fats would be better than saturated fats,” said Dr. Carl Lavie of the University of Queensland in New Orleans, who was not involved in the study. Stewart said that upcoming analyses will break down the type of fats consumed, and that the dieticians involved in the study advised patients to stick to these healthier fats. He added that the work should help allay physicians’ concerns about recommending a low-carbohydrate diet — something the medical community has largely been reluctant to do, he said.

Fat is the most valuable food known to Man May 26, 2011

Posted by ADAM PARTNERS in High Fat Low Carb Diet.
Tags: , , , , , , , , ,
1 comment so far
A space-filling molecular model of ATP, with h...

Image via Wikipedia

PROFESSOR JOHN YUDKIN

Introduction

We now know that we should eat a diet that is low in carbohydrates. But a plethora of books published in the last decade have been low-carb, high-protein, or low-carb, high-fat, or low-carb, high-‘good’-fats, or all sorts of other mixtures. In other words, the real confusion lies in what we should replace the carbohydrates with: for example, should it be protein or fats? And if fats, what sort of fats? This article, I hope, will answer the question and put any doubts out of your mind. In a nutshell, carbs should be replaced with fats, and those fats should be mainly from animal sources.

Our bodies use carbs for only one purpose: to provide energy. When we cut down on carbs, the energy our bodies need has to come from somewhere else.

There are only two choices: Protein or fat. ATP: our bodies’ fuel.

The fuel that our body cells use for energy is actually neither glucose nor fat, it is a chemical called adenosine triphosphate (ATP). A typical human cell may contain nearly one billion molecules of ATP at any one moment, and those may be used and re-supplied every three minutes.[i] This huge demand for ATP, and our evolutionary history, has resulted in our bodies’ developing several different pathways for its manufacture.

Oxygen and mitochondria

Living organisms have two means to produce the energy they need to live. The first is fermentation, a primitive process that doesn’t require the presence of oxygen. This is the way that anaerobic (meaning ‘without oxygen’) bacteria break down glucose to produce energy. Our body cells can use this method. The second – aerobic (meaning ‘using oxygen’) – method began after the Earth began to cool down and its atmosphere became rich in oxygen. After this event, a new type of cell – a eukaryotic cell – evolved to use it. Today all organisms more complex than bacteria use this property and all animal life requires oxygen to function. When we breathe in, our lungs are used to extract the oxygen in air and pass it to the bloodstream for transport through the body. And in our bodies, it is our body cells’ mitochondria – little power plants that produce most of the energy our bodies need – that use this oxygen. The process is called ‘respiration’. This process takes the basic fuel source and oxidises it to produce ATP. The numbers of mitochondria in each cell varies, but as much as half of the total cell volume can be mitochondria. The important point to note is that mitochondria are primarily designed to use fats.

Which source of base material is best?

The question now, in this era of dietary plenty, is: Which source is healthiest? There are three possible choices:

glucose, which comes mainly from carbohydrates, although protein can also be utilised as a glucose source by the body if necessary;
Fats, both from the diet and from stored body fats;
Ketones which are derived from the metabolism of fats

Not all cells in our bodies use the same fuel.

Cells that can employ fatty acids are those that contain many mitochondria: heart muscle cells, for example. These cells can make energy from fatty acids, glucose, and ketones, but given a choice, they much prefer to use fats.

Cells that cannot use fats must use glucose and/or ketones, and will shift to preferentially use ketones. These cells also contain mitochondria.

But we also have some cells that contain few or no mitochondria. Examples of cells with few mitochndria are white blood cells, testes and inner parts of the kidneys; and cells which contain no mitochondria are red blood cells, and the retina, lens and cornea in the eyes. These are entirely dependent on glucose and must still be sustained by glucose.

This means that when we limit carb intake, the same energy sources must be used, but a greater amount of energy must be derived from fatty acids and the ketones derived from fatty acids, and less energy from glucose.

Sources of glucose

To understand how a low carb diet works, we need to look at how we eat. This process is one of eating, digestion, hunger and eating again. During our evolution, we also must have experienced long periods when food was in short supply and we starved. This is a pattern our bodies are adapted to. And they have developed mechanisms to cope with a wide range of circumstances.

Firstly, the human body must contain adequate levels of energy to sustain the essential body parts that rely on glucose. The brain and central nervous system may be a particular case as, although the brain represents only a small percentage of body weight, it uses between twenty and fifty percent of all the resting energy used by the body.[ii] Fortunately the brain can also use ketone bodies derived from fats. During fasting in humans, and when we are short of food, blood glucose levels are maintained by the breakdown of glycogen in liver and muscle and by the production of glucose primarily from the breakdown of muscle proteins in a process called gluconeogenesis, which literally means ‘glucose new birth’.[iii]

But we don’t want to use lean muscle tissue in this way: it weakens us. We want to get the glucose our bodies need from what we eat. Some of that will come from carbs, the rest from dietary proteins. Our bodies need a constant supply of protein to sustain a healthy structure. This requires a fairly minimal amount of protein: about 1 to 1.5 grams per kilogram of lean body weight per day is all that is necessary to preserve muscle mass.[iv] Any protein over and above this amount can be used as a source of glucose.

Dietary proteins are converted to glucose at about fifty-eight percent efficiency, so approximately 100g of protein can produce 58g of glucose via gluconeogenesis.[v] During prolonged fasting, glycerol released from the breakdown of triglycerides in body fat may account for nearly twenty percent of gluconeogenesis.[vi] Body fats are stored as triglycerides, molecules that contain three fatty acids combined with glycerol. The fatty acids are used directly as a fuel, with the glycerol stripped off. This is not wasted. As the glycerol is nearly ten percent of triglyceride by weight and two molecules of glycerol combine to form one molecule of glucose, this also supplies a source of glucose.

The case for getting energy from fat and ketones

When most people think of eating a low-carb diet, they tend to think of it as being a protein-based one. This is false. All traditional carnivorous diets, whether eaten by animals or humans, are more fat than protein with a ratio of about eighty percent of calories from fat and twenty percent of calories from protein. Similarly, the main fuel produced by a modern low-carb diet should also be fatty acids derived from dietary fat and body fat. We find in practice that free fatty acids are higher in the bloodstream on a low-carb diet compared with a conventional diet.[vii] [viii]

But fats also produce an important secondary fuel: ‘ketone bodies’. Ketones were first discovered in the urine of diabetic patients in the mid-19th century; for almost fifty years thereafter, they were thought to be abnormal and undesirable by-products of incomplete fat oxidation. In the early 20th century, however, they were recognised as normal circulating metabolites produced by liver and readily utilised by body tissues. Ketones are an important substitute for glucose.

During prolonged periods of starvation, fatty acids are made from the breakdown of stored triglycerides in body fat.[ix] On a low-carb diet, the fatty acids are derived from dietary fat, or body fat if the diet does not supply enough. Free fatty acids are converted to ketones by the liver. They then provide energy to all cells with mitochondria. Within a cell, ketones are used to generate ATP. And where glucose needs the intervention of bacteria, ketones can be used directly. Reduction of carbohydrate intake stimulates the synthesis of ketones from body fat.[x] This is one reason why reducing carbs is important. Another is that reducing carbohydrate and protein intake also leads to a lower insulin level in the blood. This, in turn, reduces the risks associated with insulin resistance and the Metabolic Syndrome.

Ketone formation and a shift to using more fatty acids also reduces the body’s overall need for glucose. Even during high-energy demand from exercise, a low-carb diet has what are called ‘glucoprotective’ effects. What this all means is that ketosis arising from a low-carb diet is capable of accommodating a wide range of metabolic demands to sustain body functions and health while not using, and thus sparing, protein from lean muscle tissue. Ketones are also the preferred energy source for highly active tissues such as heart and muscle.[xi]

All this means that more glucose is available to the brain and other essential glucose-dependent tissues.

he case against getting energy from protein

We know, then, that dietary fats can produce all the energy the body needs, either directly as fatty acids or as ketone bodies. But, as there is still some debate about the health implications of using fats, why not play safe and eat more protein?

There is one simple reason: While the body can use protein as an energy source in an emergency, it is not at all healthy to use this method in the long term. All carbs are made up of just three elements: carbon, hydrogen and oxygen. All fats are also made of the same three elements. Proteins, however, also contain nitrogen and other elements. When proteins are used to provide energy, these must be got rid of in some way. This is not only wasteful, it can put a strain on the body, particularly on the liver and kidneys.

Excess intake of nitrogen leads in a short space of time to hyperammonaemia, which is a build up of ammonia in the bloodstream. This is toxic to the brain. Many human cultures survive on a purely animal product diet, but only if it is high in fat.[xii] [xiii] A lean meat diet, on the other hand cannot be tolerated; it leads to nausea in as little as three days, symptoms of starvation and ketosis in a week to ten days, severe debilitation in twelve days and possibly death in just a few weeks. A high-fat diet, however, is completely healthy for a lifetime.

Perhaps one of the best documented studies is that of the Arctic explorer, Vilhjalmur Stefansson and a colleague.[xiv] They ate an animal meat diet for more than a year to see whether such a diet could be healthy. Everything was fine until they were asked to eat only lean meat. Dr McClelland, the lead scientist, wrote:

‘At our request he began eating lean meat only, although he had previously noted, in the North, that very lean meat sometimes produced digestive disturbances. On the third day nausea and diarrhea developed. When fat meat was added to the diet, a full recovery was made in two days.’
This was a clinical study, but Stefansson had already lived for nearly twenty years on an all-meat diet with the Canadian Inuit. He and his team suffered no ill effects whatsoever.

Low-carb, high-fat diet and weight loss

There is just one other consideration: If you want to lose weight, the actual material you want to rid your body of is fat. But to do that you have to change your body from using glucose as a fuel to using fat – including your own body fat. This is another reason not to use protein as a substitute for carbs, as protein is also converted to glucose.

If you think about it, Nature stores excess energy in our bodies as fat, not as protein. It makes much more sense, therefore, to use what we are designed by Nature to use. And that is fat.

So what levels of carbs, fats and proteins are required?

Clinical experience and studies into low-carb diets over the last century suggest that everybody has a threshold level of dietary carbohydrate intake where the changeover from glucose-burning to fat and ketone burning takes place. This varies between about sixty-five and 180 grams of carbs per day.[xv]

If your carb intake is below this threshold, then your body fat will be broken down to generate ketones to supply your brain and other cells that would normally use glucose. In the early trials for the treatment of obesity, carb levels were very much reduced to supply only about ten percent of calories. This works out at around fifty or sixty grams of carb for a 2,000 calorie daily intake.

For diabetics, the level may need to be lower to counteract insulin resistance. Typical levels of carb intake for a type-2 diabetic are around fifty grams per day; the level should be lower still at about thirty grams a day for a type-1 diabetic.

A Polish doctor, Jan Kwasniewski, who has used a low-carb diet to treat patients with a wide range of medical conditions for over thirty years, recommends a ratio of one part carb to two parts protein to between three and four parts fat, by weight.

I see no reason to disagree with this. What it means in practice is that on a 2,000 calorie per day diet, we should get:

-Ten to fifteen percent of calories from carbs

-Twenty to thirty percent of calories from protein and

-Sixty to seventy percent of calories from fats.

Or put another way, as it is difficult to work out percentages in this way, fifty to seventy-five grams of carb and the rest from meat, fish, eggs, cheese, and their natural fats.

Potential for other diseases

The traditional Inuit (Eskimo) diet is a no-carb diet. It is notable that the Inuit diet described by Drs Vilhjalmur Stefansson and Hugh Sinclair in the 1950s is very similar in regard to percentages of fat/protein/carb intake to the experimental low-carb diets used in recent obesity studies.[xvi]

The Inuit diet was comprised of seal, whale, salmon, and a very limited amount of berries and the partially digested contents of animals’ stomachs.

On this diet, blood cholesterol levels were very high as were free fatty acids, but – and this in much more important – triglycerides were low.[xvii] [xviii]

It is interesting to note that the Inuit were of great interest to research scientists because they had practically none of the diseases we suffer, including obesity, coronary heart disease and diabetes mellitus.[xix] [xx]

References
[i]. Alberts B. Molecular Biology of the Cell, edn 4. New York: Garland Science; 2002: p 93.

[ii]. Cahill GF. Survival in starvation. Am J Clin Nutr 1998; 68:1–2.

[iii]. Exton JH. Gluconeogenesis. Metabolism 1972; 21:945–990.

[iv]. Volek JS, Sharman MJ, Love DM, et al. Body composition and hormonal responses to a carbohydrate-restricted diet. Metabolism 2002; 51:864–870

[v]. Krebs HA. The metabolic fate of amino acids. In Mammalian Protein Metabolism, vol 1, Munro HN, Allison JB, eds. New York: Academic Press, 1964:164

[vi]. Vazquez JA, Kazi U. Lipolysis and gluconeogenesis from glycerol during weight reduction with very low calorie diets. Metabolism 1994; 43:1293–1299.

[vii]. Phinney SD, Bistrian BR, Wolfe RR, Blackburn GL. The human metabolic response to chronic ketosis without caloric restriction: physical and biochemical adaptation. Metabolism 1983; 32:757–768.

[viii]. Bisshop PH, Arias AM, Ackermans MT, et al. The effects of carbohydrate variation in isocaloric diets on glycogenolysis and gluconeogenesis in healthy men. J Clin Endocrinol Metab 2000; 85:1963–1967.

[ix]. Cahill GF Jr. Starvation in man. N Engl J Med 1970; 19:668–675.

[x]. Klein S, Wolfe RR. Carbohydrate restriction regulates the adaptive response to fasting. Am J Physiol 1992; 262:E631–E636.

[xi]. Neely JR, Morgan HE. Relationship between carbohydrate and lipid metabolism and the energy balance of heart muscle. Annu Rev Physiol 1974; 36:413–459.

[xii]. Speth, John D. and Katherine A. Spielmann 1982 Energy source, protein metabolism, and hunter-gatherer subsistence strategies. Journal of Anthropological Archaeology 2:1-31.

[xiii]. Noli & Avery. Protein poisoning and Coastal Subsistence. J Archaeol Sci. 1988; 15:395-401

[xiv]. McClelland, et al. Clinical Calorimetry: XLV, XLVI, XLVII. Prolonged Meat Diets…… J Biol Chem 1930-31; 87:651, 87:669, 93:419

[xv]. Klein S, Wolfe RR. Op cit.

[xvi]. Stefansson V. The Fat of the Land. Macmillan Press, New York, 1957.; Sinclair HM: The diet of Canadian Indians and Eskimos. Proc Nutr Soc 1952, 12:69–82.

[xvii]. Bang HO, Dyerberg J, Nielsen AB: Plasma lipid and lipoprotein pattern in Greenlandic West-Coast Eskimos. Lancet 1971; I:1143–1146.

[xviii]. Feldman SA, Ho KJ, Lewis LA, et al. Lipid and cholesterol metabolism in Alaskan arctic Eskimos. Arch Pathol 1972; 94:42–58.

[xix]. Bjerregaard P, Dyerberg J: Mortality from ischaemic heart disease and cerebrovascular disease in Greenland. Int J Epidem 1988, 17:514–519.

[xx]. Sagild U, Littauer J, Jespersen CS, Andersen S: Epidemiological studies in Greenland 1962–1964. I. Diabetes mellitus in Eskimos. Acta Med Scand 1966, 179:29–39.

%d bloggers like this: