Category Archives: Weight

Wheat Belly Book Review

Wheat Belly

About the Author

Dr. William Davis is a practicing cardiologist in Milwaukee, WI with over 25 years of experience treating patients. Dr. Davis has impressive credentials: he is a graduate of St. Louis University School of Medicine and the Ohio State University Hospitals, with additional training in advanced cardiac catheterization techniques and coronary angioplasty at the Case-Western Reserve University system in Cleveland. But along the way, Dr. Davis discovered that his heart patients had a host of other problems, including obesity, gout, GERD, IBS, celiac disease, unexplained rashes and other mystifying symptoms.

There is no one as certain of the truth as a scientist cloistered in academia, performing tests on cells in a petri dish, or a researcher running computer programs to find patterns in data. While doctors share the same training in the scientific method they also live in the real world, and they often see their patients reacting very differently than popular studies and national dietary standards describe.

Dr. Davis’ Journey

Like many other medical doctors, Dr. Davis found that low carb diets were most effective in lowering his patient’s weight and improving lipid panel results. But he is aware of the exceptions, where a person’s genetic makeup can require a different approach. It is this relentless pursuit of truth and frank discussion of exceptions that makes his Track Your Plaque / Heart Scan Blog so valuable.

Dr. Davis noted his patients had dramatic improvements in other health issues after restricting carbohydrates. After thousands of years of eating carbohydrates, why would the last 50 years see such a dramatic increase in GERD, pre-diabetes, type 2 diabetes, obesity and celiac disease? Not satisfied with simply knowing the facts, Dr. Davis sought the cause of the rapid increase.

Wheat Belly

His new book, Wheat Belly provides his answer: wheat. Yes, that golden grain, enshrined in our mythology and patriotic songs, is killing us. But humans have eaten wheat for thousands of years.

So why has this seemingly benign plant that sustained generations of humans suddenly turned on us? For one thing, it is not the same grain our forebears ground into their daily bread. Wheat naturally evolved to only a modest degree over the centuries, but it has changed dramatically in the past fifty years under the influence of agricultural scientists.

William Davis, MD, Wheat Belly, (New York: Rodale Inc., 2011), 13.

About Wheat Belly, the Book

Eminently readable, Wheat Belly is written in a conversational style, suitable for any audience. Extensive footnotes are gathered together in the References section at the end of the book, where they don’t interfere with the text. Sidebars include fascinating details; patient success stories, insights into heirloom wheat, etc.

The book is just under 300 pages, divided into three main sections:

  • Wheat, The Unhealthy Whole Grain
  • Wheat and its Head-to-Toe Destruction of Health
  • Say Goodbye to Wheat

The first section gives the history of wheat, from the heirloom wheat mentioned in the Bible (einkorn, gathered by semi-nomadic tribes such as the Natufians as far back as 8500 BCE) to the modern, genetically altered variety created by aggressive cross breeding in the past 50 years.

Differences between the wheat of the Natufians and what we call wheat in the twenty-first century would be evident to the naked eye. Original einkorn and emmer wheat were “hulled” forms, in which the seeds clung tightly to the stem. Modern wheats are “naked” forms, in which the seeds depart from the stem more readily, a characteristic that makes threshing (separating the edible grain from the inedible chaff) easier and more efficient, determined by mutations at the Q and Tg (tenacious glume) genes . . . But other differences are even more obvious.

William Davis, MD, Wheat Belly, (New York: Rodale Inc., 2011), 21.
Note: the ellipsis indicates I removed a reference to a study mentioned previously in the text.

The differences in modern and ancient wheat is more than “skin deep”. On the glycemic index, whole wheat bread exceeds table sugar, scoring 72 versus sugar’s 59 on the scale. Because the carbohydrates in modern wheat are so easily digestible, eating whole grain results in the same blood sugar impact as an equivalent amount of highly processed flour. White bread, with less of the whole wheat grain, comes in at 70. A Snickers candy bar comes in lower, with a glycemic index of 41.

Interestingly, Dr. Davis’ self-experiment with baking bread showed his own blood sugar rise from 84 mg/dl to 110 mg/dl with 4 ounces of bread made with einkorn wheat. He also baked bread with modern wheat, keeping all other ingredients the same, and consumed the same four ounces. His blood sugar shot up from 84 mg/dl to 167 mg/dl.

Dr. Davis provides more detail on the genetic differences that carry unknown effects including the increase in chromosomes from 14 to 42.

Wheat and Modern Health

After establishing why modern wheat is different, Dr. Davis lists the health impact this new, genetically modified food product has introduced. First among impacts is the addictive property of modern wheat, and how it stimulates hunger. Then an extensive treatment of each health condition:

  • Obesity
  • Celiac Disease
  • Diabetes and Insulin Resistance
  • Acid Reflux and Stomach pH
  • Cataracts, Wrinkles, and the aging process
  • Heart Disease
  • Wheat’s effect on the brain
  • Acne, rashes and other skin problems
Note: I have reworded the actual chapter titles to reflect the contents.

Each chapter in this section includes footnotes to studies, as well as examples from Dr. Davis’ practice. Each topic is fully developed, and written in an easy-to-read style without excessive medical terminology (Dr. Davis explains the medical terms he does use).

Practical Application of Wheat Elimination

In the third section, Dr. Davis deconstructs the modern “eat healthy whole grains” advice. If you eliminate all wheat, do you end up with vitamin and mineral deficiency? Not if you follow his basic (and very easy) guidelines. Dr. Davis comments on the true effect of eliminating wheat:

Let me describe a typical person with wheat deficiency: slender, flat tummy, low triglycerides, high HDL (“good”) cholesterol, normal blood sugar, normal blood pressure, high energy, good sleep, normal bowel function.

William Davis, MD, Wheat Belly, (New York: Rodale Inc., 2011), 188.

The book devotes 37 pages to Dr. Davis’ simple method for eliminating wheat and replacing it with unlimited vegetables, raw nuts, grass fed beef, chicken and fish, and other whole, nutritious foods. He departs from the usual low carb / paleo prescription to warn about eating too much processed meat, with its chemical soup of seasoning, nitrates and other potentially harmful chemicals. And, a special note is made regarding the proliferation of “gluten free” products that substitute fructose and “chemical soup” in place of wheat that may still pose health risks. Instead, Dr. Davis provides a variety of great wheat free recipes to provide an insight into managing a diet without wheat, introducing wonderful variety and enjoying the journey.

My Conclusions

I am by nature a skeptical person, but my personal experience with low carb dieting led me to believe, long before I discovered Dr. Davis’ blog, that I may have a “hidden” wheat allergy. After suffering from painful GERD for over a decade, I noted a rapid decrease in symptoms when I started a low carb diet. My GERD does not return when I have the occasional indulgence of ice cream while on a cruise, but comes back with a vengeance when I consume wheat products. My personal experience is not scientific proof, of course, any more than the sidebar stories of dramatic cures are scientific proof in Wheat Belly.

I suspect I will still eat bacon and other processed meats, and I don’t share the enthusiasm for grass fed organic beef and free range chickens and eggs. But those quibbles aside, Dr. Davis’ clinical experience, supported by his scientific research as revealed in 16 pages of references, make a powerful argument that I find hard to refute.

It is easy to do your own experiment; there are no adverse health effects to eliminating wheat and eating according to Dr. Davis’ easy prescription. Two weeks is usually sufficient to notice differences in some conditions. I can heartily recommend Wheat Belly as a practical guide to seeing if you also have a “hidden” wheat allergy.


Other Reviews:
Book Review: Wheat Belly, by Tom Naughton at Fathead.
Review: Wheat Belly by Dr.William Davis, by Dana Carpender at Hold the Toast.
Wheat Belly Book Review, by Joe Lindley at Stop Craving Sugar.

Dr. Davis’ Blogs:
Track Your Plaque / Heart Scan Blog
Wheat Belly Blog

Disclaimer: Dr. Davis provided a complimentary review copy of the book, but did not attach any editorial restrictions to the review.

Mass Media Acceptance

The evidence that the Low Carb Age is upon us keeps amassing, albeit with the usual caveats to assuage guilt. As the authors of Mistakes Were Made (But Not by Me) tell us, people in positions of authority rarely admit they were wrong.

Nevertheless, the truth begins to squeak out. This week the NY Times’ Tara Parker-Pope’s Phys Ed column reports on a significant new study from Johns Hopkins to be published this Friday:

With the memory of Memorial Day cheeseburgers and bratwursts still lingering, many of us may be relieved to hear that a new study suggests that a meaty, high-fat, Atkins-style diet can do more than contribute to rapid weight loss. It may also be less unhealthy for the heart than many scientists had feared — provided you chase the sausage with a brisk walk.

So Close, Yet So Far

Parker-Pope makes the mistake of insisting exercise was proven to be part of the solution, but the study shows no such thing. It specifically compares a low fat to a “low carb” diet, both with the same amount of exercise. As The Behavioral Medicine Report explains:

Low-carb dieters showed no harmful vascular changes, but also on average dropped 10 pounds in 45 days, compared to an equal number of study participants randomly assigned to a low-fat diet. The low-fat group, whose diets consisted of no more than 30 percent from fat and 55 percent from carbs, took on average nearly a month longer, or 70 days, to lose the same amount of weight.

Both groups had an exercise component. In the absence of a correlating study showing that the same diets without exercise has a different outcome, Parker-Pope’s assertion is without any foundation. Pre-conceived notions are hard to shake.

How Low is Low

As we’ve seen in other studies, the term “low carb” used here is inexact. The low carbohydrate group consumed up to 30% of their calories from carbs. Considering this a low carb diet is a bit of a stretch. Most people adhering to a low carb diet to lose weight start with about 40 grams of carbohydrates per day, or 160 calories from carbs. For a healthy man consuming 2,500 calories per day, carbs during Induction on Atkins represent about 7% of calories. That same man on the test diet in this study would be consuming about 185 grams of carbs. That’s higher than many people on a low carb maintenance diet.

This study did reduce calorie content by about 700 calories over the baseline for each individual. Even for a 2,000 calorie diet, the “low carb” dieter is consuming 150 grams of carbs.

Why Calories Don’t Matter

This study provides yet another example why the “calories in / calories out” model is flawed, as the low carb group lost weight 30% faster than the low fat group. They both consumed 700 fewer calories per day than before, but the low carb group lost weight faster. If the body reacts to all food the same way, as a strict “calories in / calories out” model suggests, then both groups would have lost weight at the same rate. But in study after study, we find that the low carb group loses weight faster and with less hunger than the low fat group. What you eat matters as much as how much you eat.

The Original Purpose

The trial was designed to test the differences in vascular function for people on both diets, and both showed no change. It is the first study to actually test vascular function among a group of people. That is good news for people considering a low carb diet. As lead investigator exercise physiologist Kerry Stewart, Ed.D, says:

“Our study should help allay the concerns that many people who need to lose weight have about choosing a low-carb diet instead of a low-fat one, and provide re-assurance that both types of diet are effective at weight loss and that a low-carb approach does not seem to pose any immediate risk to vascular health,” says Stewart. “More people should be considering a low-carb diet as a good option,” he adds.

The study is due to be published Friday, June 3.

Never Too Late

Richard at Primal Fed has a thought provoking post on “When is it Too Late to Get Healthy”. At least it got me thinking not only of my journey, but also of attitudes toward diet and exercise from different perspectives.

Richard states he is a 26 year old male, and his personal bio on the site shows his amazing quick transformation simply living a primal lifestyle. His wife, Amanda, is a few years younger and also has an inspiring story.

Kids today …

In their cases, change was quick and satisfying. Like most who adopt a low carb / paleo lifestyle, they can’t imagine going back to their old ways. But coursing through their bodies are the hormones of youth, making weight loss easier and exercise more beneficial. That’s not to diminish the dramatic improvements they have made; its just a biological fact. For women generally, and especially after menopause, losing weight is much harder. Men over 50 have much the same problem. And for both sexes, middle age brings biological changes that make it harder to build muscle mass. There are individual exceptions, but in general, a 50 year old man is going to have a harder time than a 25 year old building muscle. Sorry folks, that’s just the way it is.

Richard mentions in his post that his grandmother stated it was “too late for her” 15 years ago, when she was 50 years old. Too late?

Is it Too Late?

If you are thinking about having a perfectly fat tummy, yeah, 50 is probably too late. If you are thinking about having defined abs, huge arms and massive muscles, yeah, 50 is probably too late. But if you are thinking about getting healthier, jettisoning all those pills for high blood pressure, GERD and cholesterol, then 50 is not too late. 60, 70 and even 80 years old are not too late.

Here’s the thing: body composition changes as we age. The alternative to this happening is to die young. So you won’t look like a 26 year old if you are 50. You might get close with a ton of work, effort, hair dye and plastic surgery. But you won’t really have the body of a healthy 26 year old.

The focus for the over-50 set should be getting healthier. Following a low carb or primal lifestyle will result in weight loss, but not to the same extent as a 26 year old. The goal should be to be healthier, and the key to that is to reduce processed carbohydrate rich foods, reduce triglycerides, fasting blood sugar, and yes, lose weight if in the obese category. But don’t lose too much weight.

The Myth of “Normal Weight”

As we’ve shown before, the charts and formulas used for “ideal weight” are wrong. Studies have shown that BMI, the formula used by most doctors, reveal that those in the overweight category are 17% less likely to die than people in the “normal” weight category. That’s right; the reason you see so many fat old people is that the skinny ones died already. It is better, statistically, to be in the overweight category when using BMI than in the “normal” weight category.

Two years ago, I was 53 years old, weighed 248 pounds and had triglycerides of 344, high blood pressure, GERD and didn’t sleep at night. Six weeks after starting a low carb diet, I had lost a little weight, but my triglycerides fell to 106, I was off high blood pressure medicine and my GERD was gone.

I lost weight steadily that first year, then plateaued at just over 200 pounds, where I am now. I could lose more weight with some effort, but I’m now simply “overweight” rather than “obese”, my blood panel is much better and I no longer have a diagnosis of metabolic syndrome or pre-diabetic. I’m pretty satisfied with that. So I’ll continue on this road.

And if I lose more weight, that’s great. If I don’t, that’s OK too, because I’m improving my health. I’d rather be alive and have an overweight BMI at 85 than assume room temperature in a prettier body at 70.

Its Not Too Late

Managing expectations is probably as important as managing your diet. Don’t beat yourself up if you’re a premenopausal female and your male partner loses more weight while eating more food (the bastard!) Unless you want to grow facial hair and deepen your voice by taking testosterone supplements, that’s the way it is.

Don’t beat yourself up if you are over 50 and you aren’t getting the same results as a 25 year old. They have youth as an advantage, and its one that you can’t borrow, buy or otherwise obtain, no matter how many late night infomercials you view.

He’s not your enemy. Most of the time, anyway.

You can improve your health, often dramatically, by adopting a low carb or paleo lifestyle. Ask your doctor about it, and phrase it this way: “Are they any health problems I currently have that would be exacerbated by eating a low carb diet?” Get the straight answer to that question. Certain health conditions like kidney or liver disease, gout or digestive disorders may argue against adopting a higher protein diet, and only you and your doctor really know if you have those.

Beyond that specific question, your doctor may recommend the standard, low fat bound-to-fail diet they are so fond of in medical circles. Barring a specific medical reason to avoid a low carb diet, see if your doctor will work with you to adopt either of the low carb diets featured below.


Leptin Resistance

What is Leptin?

Leptin is a hormone released by fat cells that helps regulate hunger. And it may hold the key to why a low carb / paleo diet works for so many people.

Role of Leptin in Hunger Signals
Leptin and Hunger
(Click Image to Enlarge)

Success on a low carb / paleo diet is often attributed to “never feeling hungry”, an effect not seen on other diets. People point to the satiating aspects of fat or protein in eliminating hunger, but dieters may be suffering from a rarely diagnosed condition called leptin resistance that is corrected by the low carb diet.

Leptin circulates through the bloodstream in an amount directly proportional to the amount of fat you have. In theory, the more leptin you have circulating the less you will eat, because it signals that you have enough stored energy for all your metabolic processes. When leptin levels dip, it signals the brain that you are hungry.

So, that means fat people should never be hungry, right? Not so fast, grasshopper.

Resistance is Futile

Most low carbers are familiar with the concept of insulin resistance in those with type two diabetes and metabolic syndrome. In a healthy individual, insulin signals the cells that glucose is available, and the cells respond and allow the glucose to enter the cell (if they need the energy). Insulin resistance is a condition where the cells become resistant to the effects of insulin, requiring more and more insulin to deal with blood sugar levels. If a regular cell opens the door to a gentle knock, the insulin resistant cells respond only to ferocious pounding on the door with a battering-ram’s worth of insulin. The pancreas, which produces insulin, cannot keep up with the demand for more and more insulin, and dangerously high levels of blood glucose result.

A similar thing happens with leptin resistance, but through a different mechanism. There’s no shortage of leptin in an otherwise healthy obese person, and the fat cells never grow tired of producing it. But the circulating leptin is blocked and cannot turn off the hunger signal. The fat person remains hungry. And hungry people eat.

What Causes Leptin Resistance?

Some have theorized that dietary fat and blood glucose levels interfere with leptin. While there is a link between leptin resistance and the levels of fat circulating in the blood (triglycerides), eating dietary fat doesn’t seem to have an effect. Recent evidence showing a diet high in fructose contributes to leptin resistance adds to the growing body of evidence against high levels of fructose in the diet. The amount of fat in the diet did not matter; leptin resistance peaked with the high fructose diet, and reversed itself to normal levels when the rats ate a sugar free diet, no matter how much fat they had. Lucky rats.

We know that leptin signals our brain that enough energy is present, and the body does not need any more food. Leptin is able to cross the “blood brain barrier” (BBB) to do this. The BBB is a protective system of small capillaries that protects the brain from most chemicals but allows the important ones through. It works like a filter. So what causes the curious case of leptin resistance, where this essential hormone is blocked by the BBB? As Dr. Mike Eades explains:

Research done a couple of years ago in St. Louis and in Japan pinpointed the problem. Triglycerides – fat circulating in the blood – interrupts the passage of leptin across the BBB. If trigylcerides are high, which they are in most obese people, then, basically, they block the movement of leptin into the brain. So, leptin levels are elevated in the blood, and triglycerides keep the leptin from getting to where it needs to get to shut off hunger.

One Solution

Controlling trigylceride levels can reverse leptin resistance. In my own experience, hunger evaporated on my low carb diet as my triglycerides fell from 344 to 105. Before that, I was often hungry, even after eating past the feeling of fullness and often to discomfort. On my low fat diet 15 years before, I was miserable because I was always hungry. But that, as they say, is a personal testimony and not a scientific finding. Too bad I’m not a rat.

The easiest way for most people to lower triglyceride levels is to adopt a very low carb diet (less than 50 grams of carbohydrate per day), then transition to a moderate carb diet devoid of most grains. Niacin and fish oil have also proven to be effective in many people, even those with genetic reasons for high triglycerides (familial hypertriglyceridemia). I combine all three approaches, and have found the eliminating any one of those results in my triglycerides rising again. Management of triglycerides in this way is done in concert with a physician and blood tests. Those with chronic health problems should check with their doctors first, of course, especially those with reduced liver or kidney function, or those suffering from conditions such as gout that require specific diets.

Resisting Resistance

Humans are adapted to eat a certain diet, and in terms of adaptation, the modern agricultural era is a blip on the radar screen. We simply haven’t had time to adapt to large quantities of grain and other carbohydrates in our diets. The inexpensive access to readily available carbohydrates is new, barely 10,000 years old, and our biological machinery is not able to handle it. That’s the philosophical framework under girding the modern low carb / paleo diet movement. The rise of leptin resistance is just one more metabolic condition that supports the effectiveness of a low carb / paleo lifestyle.

Other Resources

MegaSearch: Leptin Resistance

Heart Scan Blog: Niacin

Heart Scan Blog: Fish Oil

Protein and the Low Carb Dieter

Even the American Diabetes Association has seen that, to use the stilted language of one study:

… a joint committee of the American Diabetes Association, North American Society for the Study of Obesity and the American Society for Clinical Nutrition suggested that a low-carbohydrate diet may be preferred to a low-fat diet for the induction of weight loss and glycaemic control in subjects with type 2 diabetes.

That study, published in the Diabetes/Metabolism Research and Reviews journal in March, 2011, represents a bit of a turn-around for the ADA, which has long suggested a medium carb diet for type 2 diabetics.

How Much Protein?

There are concerns expressed, mostly by friends, that too much protein will cause kidney stones, impair liver function, contribute to bone loss, and cause other problems.

Historically, the recommended amount of protein has been expressed using a grams per kilogram ratio, with .66 to .8 grams of protein per kilogram of lean body mass total body weight. A man weighing 200 pounds weighs 91 kilograms, so the total protein recommended would fall into the 60 to 73 gram range. For a woman at 140 pounds (63 kg), the range is 42 to 50 grams. But it’s common to read recommendations on low carb forums that up to 150% of those levels is fine.

When I weighed 250 pounds, my minimum protein requirement according to The Protein Power Lifeplan was 120 grams per day, or about 1.1 grams per kilogram of weight. That’s a bit more than the .8 grams per kilogram recommendation. At .66 grams, the recommended protein level would be 75 grams. Expressed in terms of caloric content, 120 grams of protein represents 480 calories, or about 19% of a 2,500 calorie diet. (Note, the paragraph above was edited on April 3, 2011 to correct the numbers given in the Protein Power Lifeplan).

Dissenting Views

The Perfect Health Diet Blog advocates limiting protein to about 10% 15% of total caloric intake, a number very close to the .66 grams of protein per kilogram of weight. That blog post also has important information regarding protein maximums for pregnant women and children … a warning to those with “paleo babies” who, evidently, want to duplicate the insanity of vegan couples who starve their babies with inadequate diets, a problem that a Google search indicates happens every few years. (Babies are not just “little people”; they have unique nutritional needs. Nature itself provides a low 7% protein diet in breast milk).

Real Protein Requirements?

But, for non-pregnant, adult women and men, are the protein levels satisfactory? There is some evidence that we may have been wrong all along with the .66 to .8 gram of protein per kilogram of weight calculation.

In January, 2010, a study examined the method of determining the protein requirements of adults, and concluded that the proper amount of protein may be .93 to 1.2 grams per kilogram of body weight. Our 200 pound man is now expected to eat up to 109 grams of protein (17% of the caloric intake on a 2,500 calorie diet).

Problems with Protein?

But is that too much? What about our friend’s concern that our kidneys will produce stones, our livers will cease to function, and our bones will leech calcium and become brittle? A study published in December, 2010, in the Nutrition Journal concluded:

… protein-enriched meals replacements as compared to standard meal replacements recommended for weight management do not have adverse effects on routine measures of liver function, renal function or bone density at one year.

In this study, the subjects on the high protein diet consumed 2.2 grams per kilogram of LBM, more than twice the amount recommended on most low carb diet plans. It looks like the low carb forum participants may have been right all along; you can safely go 150% of the minimum protein requirements without too much concern.

But, there are caveats

These studies look at healthy, adult men and women, free of liver, kidney or other disease. Anyone with any chronic condition, or on any medication, should check with their doctor before adopting any diet.

And remember, children and pregnant or nursing women are unique and the same rules simply don’t apply.

Metabolic Advantage

The concept of a metabolic advantage with low carb diets is hotly debated. A quick MegaSearch shows hundreds of articles and blog posts, including some spirited debates. So what is this so-called metabolic advantage?

Dr. Michael Eades explains it this way:

When two groups of subjects both eat the same number of calories (but provided by diets of different macronutrient compositions) and maintain the same activity level, yet one group loses more weight than the other, the group losing the greater weight is said to have a metabolic advantage. Or, more specifically, the diet driving the weight loss is said to provide a metabolic advantage.

The debates among doctors, researchers and advocates sometimes gets heated. I won’t post a link to the profane and, in my opinion, irrational posts by Dr. Eades’ opponent in that particular debate, but Dr. Eades includes it in his blog post.

The literature does show an apparent metabolic advantage in studies. Just this week (March 2, 2011) the American Journal of Clinical Nutrition published a new study, Short-term weight loss and hepatic triglyceride reduction: evidence of a metabolic advantage with dietary carbohydrate restriction:

The aim of this study was to determine the effectiveness of 2 wk of dietary carbohydrate and calorie restriction at reducing hepatic triglycerides in subjects with NAFLD [Non-Alcoholic Fatty Liver Disease].

NAFLD, or “Non-Alcoholic Fatty Liver Disease” is a condition where the liver “gets fat”, resulting in reduced liver function. It is growing at an alarming rate, with some pointing towards increased fructose consumption as a likely cause (fructose is metabolized by the liver).

Like other studies, this one notes a “metabolic advantage” with a low carb diet:

Two weeks of dietary intervention (≈4.3% weight loss) reduced hepatic triglycerides by ≈42% in subjects with NAFLD; however, reductions were significantly greater with dietary carbohydrate restriction than with calorie restriction. This may have been due, in part, to enhanced hepatic and whole-body oxidation.

The phrase “significantly greater with dietary carbohydrate restriction than with calorie restriction” is the evidence the researchers note as a “metabolic advantage.”

The hotly contested debate will continue, of course, but as evidence mounts that lower carb diets result in greater weight loss and less hunger than calorie reduced calorie diets, can the debate sustain itself for very long?

Knockout: Low Carb vs. Low Fat

The New England Journal of Medicine noted the results of a study examining the best way to maintain weight loss:

We enrolled overweight adults from eight European countries who had lost at least 8% of their initial body weight with a 3.3-MJ (800-kcal) low-calorie diet. Participants were randomly assigned, in a two-by-two factorial design, to one of five ad libitum diets to prevent weight regain over a 26-week period:

  • a low-protein and low-glycemic-index diet
  • a low-protein and high-glycemic-index diet
  • a high-protein and low-glycemic-index diet
  • a high-protein and high-glycemic-index diet
  • or a control diet

Low carb diets generally fit into the two “low glycemic index” diets, with most low carbers getting toward the relative high end of protein.

One of the interesting facts about the study is that the low carb dieters adhered to the diet at a much greater rate than their counterparts; the study says about 26% of the dieters eating a low carb variant dropped out, compared to 37% who dropped out of the higher glycemic-index diets. And these were diets where the people could eat until satisfied, not adhere to a limit imposed by the study authors. You would think a diet that allowed you to eat foods rating higher on the gycemic-index would be easier, right?

Not so, and Dr. John Briffa notes the reason:

This helps to explain why individuals who adopt lower-carbohydrate approaches (generally low-GI and usually quite-rich in protein) find they’re less hungry, and eat less as a result. Never mind that – having worked with literally thousands of real people over 20 years I have become convinced that this way of eating really does, overall, trump others (e.g. low-calorie, low-fat) in terms of sustainable weight loss. And this is why it forms the basis of the advice I offered in my latest book Waist Disposal

I have seen countless individuals get on and off ‘diets’ and therefore suffer cycles of weight loss and weight gain. What is it that causes individuals to default back to their original diet? Lots of things, but one factor that almost always plays a part is hunger. It’s a plain and simple fact that unless forced, individuals tend not to tolerate hunger at all well in the long term.

So which diet was the least successful in maintaining the weight loss? As the study tells it:

In the analysis of participants who completed the study, only the low-protein–high-glycemic-index diet was associated with subsequent significant weight regain (1.67 kg; 95% confidence interval [CI], 0.48 to 2.87).

That “low-protein-high-glycemic-index diet” is the standard American diet, with 60 to 70% of calories from foods high on the glycemic index, like whole grains, whole wheat bread, pasta, fruit juices, etc.

For most people, a diet that focuses on adequate protein, higher fat intake and reduced carbohydrates satisfies hunger more. And as Dr. Briffa notes, hunger just isn’t tolerated well. Even if you can eat all the “whole grains” you want.

Lies, Damn Lies and Statistics

The title of this article refers to the phrase Mark Twain popularized, that he attributed to Disraeli. There is a touch of irony in that no one can actually pinpoint where Disraeli said any such thing. But you get the point.

Sometimes, even when its good news for low carbers, the stats are manipulated in such a way to mask the true advantage.

Dietary science is the bastard son of science, with correlation in cohort studies trumpeted as “proof” by the media. A randomized controlled study is a better model as it helps eliminate various types of bias.

We were all excited to see the new study that compared low fat to low carb dieting, and found that cardiovascular risk factors were not greater with a low carb diet … in fact, they were lower! And this was a randomized controlled trial, with over 300 participants who were followed over a two year period; that’s a very long time in dietary science!

But in scouring the web for more authoritative voices to add to our new low carb news aggregator, I found something shocking. From a layman’s perspective, the study is horribly flawed, and grossly underestimates the beneficial impact of a low carb diet. How so? The researchers used a statistical method called “Intention To Treat” (ITT). This method uses the results from all the participants, even those that drop out, diluting the true impact of the diet on those that continue to follow it. As Pål Jåbekk writes in the Ramblings of a Carnivore blog:

Now, intent to treat analysis is a perfectly fair method to use. But it means that the results cannot tell us which dietary approach is the more effective. If we want to know which diet causes the greatest weight loss we must look at the data from the participants that actually followed the diet, and only those. What the results of this recent study tells us, is the effect of being put on a diet as opposed to the effect of following one. Is it really so bloody impossible to include data on compliers vs non compliers? As interesting as it is to know the effect of being put on a diet I for one would also like to know the actual effect of following the diets.

Jåbekk links to a paper by Richard D Feinman on ITT where the curious practice is further explained:

In ITT, the data from all subjects who are randomized to treatment are analyzed regardless of whether subjects followed the protocol or not (“analyze as randomized”). At first hearing, the idea of ITT is counter-intuitive if not completely irrational – why would you include in your data, people who are not in the experiment? – suggesting that a substantial burden of proof rests with those who want to employ it. No such obligation is usually met and, particularly in nutrition studies, such as comparisons of isocaloric weight loss diets, ITT is frequently used without justification. ITT analyses are typically reported in a way that implies that they have the final say on efficacy and it is even argued that, once assigned to an experimental group, all data must be included in the analysis even if subjects do not comply with the protocol.

Feinman’s article includes this table, showing how ITT masks the true response of those that follow a low carb diet in two prior studies:

Table 1

Weight Loss in Diet Comparisons and the Effect of Analysis.

Data for 12 months Weight Loss (kg)

With Drop-outs SD Only Study Subjects SD

Foster, et al. low carb 4.4 6.7 7.3 7.3
low fat 2.5 6.3 4.5 7.9
difference 1.9 2.8

Stern, et al. low carb 5.1 8.7 7.3 8.3
low fat 3.1 8.4 3.7 7.7
difference 2 3.6

Feinman Nutrition & Metabolism 2009 6:1   doi:10.1186/1743-7075-6-1

Keep in mind that in these prior studies, the end result reported in the paper was that weight loss was just about equal with either a low carb or low fat diet. That’s the message if you use the numbers that include the people who dropped out of the diet, in the “With Drop Outs” column, where the low carb group in the “Foster, et. al.” study only lost 1.9 kg more than the low fat group. But look at the column titled “Only Study Subjects”, comparing those that actually followed the low carb or low fat diet, and you find that the low carb dieters actually lost 2.8 kg more than the low fat dieters (47% more weight). For the “Stern, et. al.” study, we find even greater numbers: a difference of 2 kg between the diets using ITT and 3.6 kg when counting those that actually followed the diet plans. That’s 80% more weight loss. Feinman continues:

Thus, the conclusion that weight loss is the same at 1 year on low-carbohydrate diets and conventional diets comes from an ITT analysis and, as stated, is misleading. Because dieters and practitioners reasonably want to know the potential of a diet, it seems that authors must be very circumspect about describing results. The ITT analysis, again, only answers the question about assignment to a diet in a particular experimental setting, and does not address the question as to which is the more effective diet if adhered to. The fact that it is acknowledged that the substantially greater improvement in plasma triglycerides on the low carbohydrate diet compared to the low fat diets persisted for one year should have been taken as a sign that it would be surprising if the diets were the same.

While the news about the good results was welcome, it is disheartening to see that the results are still not being reported in an easy to understand manner. It appears the new study did not include the results only from the people who adhered to the diet, but only reported the “Intention to Treat” numbers.

Outcomes After 2 Years Compared

A 2 year comparison of reduced calorie, low fat diets and low carb diets, with counseling and medical intervention, was published today in the Annals of Internal Medicine:

Successful weight loss can be achieved with either a low-fat or low-carbohydrate diet when coupled with behavioral treatment. A low-carbohydrate diet is associated with favorable changes in cardiovascular disease risk factors at 2 years.

The study was a randomized, parallel group trial spread over three medical centers and consisting of 307 participants, lasting two years.

For the low carbohydrate group, the study limited the intake of carbohydrates to 20 grams per day for 3 months. There was no restriction on the amount of fat or protein the low carb participants could eat. After three months, the low carb participants increased their carb intake by 5 grams per day for a week, then increased in the next week by another 5 grams, monitoring the results until they reached a point where they were not losing weight. The counselors fine-tuned the diet for each individual and gave them encouragement.

For the low fat group, daily calories were slashed to 1200 to 1800 kcal per day, with less than 30% of the calories from fat. Like the low carb group, the low fat dieters were given “comprehensive behavioral treatment”.

Weight loss was approximately 11 kg (11%) at 1 year and 7 kg (7%) at 2 years. There were no differences in weight, body composition, or bone mineral density between the groups at any time point. During the first 6 months, the low-carbohydrate diet group had greater reductions in diastolic blood pressure, triglyceride levels, and very-low-density lipoprotein cholesterol levels, lesser reductions in low-density lipoprotein cholesterol levels, and more adverse symptoms than did the low-fat diet group. The low-carbohydrate diet group had greater increases in high-density lipoprotein cholesterol levels at all time points, approximating a 23% increase at 2 years.

The low carb group had better blood pressure, triglyceride levels, vLDL, and higher levels of the good cholesterol, HDL. Plus, they were eating BACON.

It would be interesting to see if the low carb group was happier with their new eating regime than the low fat group. The study did say that the attrition rate was pretty high for both groups at the two year mark.

The study was funded by the National Institutes of Health.