Category Archives: Low Fat Lie

Diet, Gene Expression and Diseases

How Diet Affects Gene Expression

A new study from the Norwegian University of Science and Technology – Trondheim has mapped the way that diet affects gene expression. Gene expression is the “process where information from a gene’s DNA sequence is translated into a substance, like a protein, that is used in a cell’s structure or function.”

The study found that different types of foods cause different reactions in the cells themselves. Some of these reactions are considered good, and some are destructive, leading to increases in inflammation. As Dr. Steve Parker has noted, inflammation is thought to have a role in developing atherosclerosis (the cause of heart attacks and strokes), type 2 diabetes, and some cancers.

Bad News for Calories In/Calories Out

The idea that a “calorie is a calorie” and that the secret to losing weight and a healthy lifestyle is “eat less, move

How Calories Are Measured
A "bomb calorimeter" is used to determine the calories in food

more” assumes that all food is equal. The solution for a calorie counter is to simply induce a “calorie deficit” by burning more energy than you eat. When you have a calorie deficit of 3,500, you lose a pound of fat. This approach does work for some people, most notably young, healthy males, but rarely works as well for those in middle age. And women have an especially hard time losing weight this way.

As I noted in Eating Fat Does Not Make You Fat, it does matter what foods you eat. In that article we show that in every single test of a low carb vs. low fat diet, the low carb group has no calorie restriction. Yet they lose more weight, faster, than any other diet. The low fat diet proponents claim the low carb diet folks are “cheating” by spontaneously eating fewer calories.

This new study should put the final nail in the coffin for “calories in / calories out” mantra from a health perspective. It does matter what you eat, even more than how much you eat.

How The Study Was Conducted

The main study included 28 slightly overweight men and women who ate two different powdered diets. This type of controlled study on actual people, rather than a meta-analysis of statistics from other studies, shows actual cause-and-effect of the different diets for this group of men and women. A “cleansing period” of a week allowed the participants to eat normally between the diets. The researchers had the participants drink the liquid diet six times a day, with each participant’s caloric intake calculated to maintain their current weight.

The first powdered diet provided 65 percent of the calories from carbohydrates, 15 percent from protein and 20 percent from fat. For a 2,000 calorie diet, that’s 1,300 calories from 325 grams of carbohydrates, 300 calories from 75 grams of protein, and 400 calories from 44 grams of fat. That is very close to the USDA recommendations for a “well balanced diet”.

The second powdered diet  provided calories close to one-third carbohydrates, protein and fat. For our 2,000 calorie diet, that would translate into 667 calories for each macro-nutrient, with 167 grams each of carbohydrates and protein, and 74 grams of fat.

Blood tests were conducted before and after each diet period. All of the measurements of changes in gene expression were done so that each individual’s difference in gene expression was compared with that person alone. The results were then compiled.

Johnson says the studies resulted in two important findings. One is the positive effect of many meals throughout the day, and the details about the quality and composition of components in an optimal diet, including omega-3 and omega-6 fatty acids. The second is that a carbohydrate-rich diet, regardless of whether or not a person overeats, has consequences for genes that affect the lifestyle diseases, she says.

It’s important to remember that this is not a weight loss study, as the liquid diets were carefully measured to keep the participants at a steady weight. This prevents the temporary “bad effects” of weight loss from showing in the blood samples (those effects are explained clearly by Dr. Davis in his post about the alarm some dieters have after losing weight and seeing blood test results).

What the Study Found

For many health issues, there isn’t a single controlling gene. The researchers had to compare multiple genes to see how they reacted to the different diets. The article quotes professor of biology Berit Johansen:

“We are talking about collecting a huge amount of information,” says Johansen.

“And it’s not like there is a gene for inflammation, for example. So what we look for is whether there are any groups of genes that work overtime. In this study we saw that an entire group of genes that are involved in the development of inflammatory reactions in the body work overtime as a group.”

The lower carbohydrate diet not only reduced inflammation, but reduced activity of the genes associated with type 2 diabetes, cardiovascular disease, Alzheimer’s disease and some forms of cancer.

“It was interesting to see the reduction in genetic activity, but we were really happy to see which genes were involved. One set of genes is linked to cardiovascular disease. They were down-regulated in response to a balanced diet, as opposed to a carbohydrate-rich diet,” she says. Another gene that was significantly differently expressed by the diets that were tested was one that is commonly called “the youth gene” in the international research literature.

“We haven’t actually stumbled on the fountain of youth here,” Johansen laughs, “but we should take these results seriously. The important thing for us is, little by little, we are uncovering the mechanisms of disease progression for many of our major lifestyle-related disorders.”

Problems with the Article

The article shows that the idea of “calories in / calories out” is at best a simpleton’s approach to healthy eating, as it ignores the micro-nutrient composition of the foods we eat. It also provides direct evidence that the low fat diet is dangerous even though it is often prescribed as a way to reduce cardiovascular heart disease and presented as the “healthy alternative” to the standard American diet. But the good professor veers off the rails with some unsubstantiated advice:

The professor warns against being caught up in the fat trap. It’s simply not good to cut out carbs completely, she says. “The fat/protein trap is just as bad as the carbohydrate trap. It’s about the right balance, as always.”

She says we must also make sure to eat carbohydrates, proteins and fats in five to six smaller meals, not just for the main meal, at dinner.

“Eating several small and medium-sized meals throughout the day is important. Don’t skip breakfast and don’t skip dinner. One-third of every meal should be carbohydrates, one-third protein and one-third fat. That’s the recipe for keeping inflammatory and other disease-enhancing genes in check,” Johansen explains.

The problem with this portion of the article is that there is no evidence presented for her claim that a “balanced” intake of the three macro-nutrients is better than a lower carb variant. The study tested only a high carb / low fat diet against a lower carb diet. In order to make the claim above she would have to actually test the hypothesis that getting one-third is better than getting one-fifth of your calories from carbohydrates, as a typical 100 gram per day “maintenance level” low carb diet would provide. While there’s always the possibility that the professor has done such as study, and her statement is based on that prior study, I suspect she is “thinking linearly”. She really has no way to conclude that one-third carbohydrates is better than one-fifth carbohydrates until she tests it.

The study does provide direct evidence that the diet advice given to the American people by the USDA, that 65 percent of their calories should come from carbohydrates, is actually dangerous. Rather than reducing the risk for cardiovascular disease, type 2 diabetes, Alzheimer’s disease and some forms of cancer, the high carbohydrate diet “turns on” the genes associated with those chronic health problems.

The article also does not provide a citation for the idea that eating six times daily is better than three or four times (more frequent meals are usually recommended in higher carb diets to try and control the wild blood sugar spikes that occur). Many paleo / primal dieters find that eating “when hungry” leads them to fewer meals, often only two, in a typical day.

It Could Work

Even with my reservations, having someone adopt a true “balanced diet”, with one-third of their calories from carbohydrates, protein and fat, would undoubtedly lead to better health than the Standard American Diet. If the goal is to lose weight, reducing carbohydrates further, to 20 percent of total caloric intake, will usually result in slow, steady weight loss. To lose weight at the rate of 1 to 2 pounds per week, a true low carbohydrate diet, below 50 grams of carbs per day, will result in the best results for most people.

 

Fat Doesn’t Make You Fat

Eating Fat Does Not Make You Fat

Contrary to popular opinion, eating a diet rich in dietary fats does not make you fat. The prejudice against saturated dietary fat, as found in meat, diary, and some plant sources such as coconut, is based on extrapolations and incorrect conclusions.

It’s Not About Calories

One reason the “fat makes you fat” mantra has been repeated so often is that of the three macro-nutrients, fat contains the most calories per gram. Fat contains 9 calories per gram, while the other two, carbohydrates and protein, each contain about 4 calories per gram. Therefore, eat more grams of protein and carbs, and less of fat, and you reduce your caloric intake, and will lose weight.

Real life interferes with this fantasy. People don’t eat grams, they eat food. Arguments about whether a “calorie is a calorie” no matter its source don’t hold up to common sense. Instinctively we know that eating 125 teaspoons of table sugar is not as healthy as eating the 2500 calories in a well designed diet plan. And its more than just the nutritional value of foods; even if Big Food decides to infuse table sugar with vitamins, we know eating nothing but sugar isn’t good for us.

One of the “criticisms” of a low carb diet is that people spontaneously reduce the amount of calories they consume when they replace carbohydrates with fat and protein. This is seen as somehow cheating. Think about it, on every other diet the studies have to closely monitor the caloric intake of foods. But those same studies don’t put any calorie restrictions on the low carb diet group. They count only carbs. The low carb diet group in study after study loses more weight, faster, than any other diet group. The low fat advocates protest that the low carb diet group spontaneously eats less calories, and have therefore cheated.

Presumably, they want you to feel hunger, and be tempted to cheat on your diet, so that they can continue feeling superior to the weak willed fat people who simply can’t “move more and eat less.” What kind of diet is easier to adopt? One in which you are hungry, or one where you spontaneously reduce food intake?

There are numerous internet debates on whether a low carb diet has some magic “metabolic advantage”, or if the low carb diet is simply more satisfying, so people naturally eat less. A new study suggests that a high fat diet may actually cause the body to burn fat faster, as explained below.

Fat is Energy Dense

At 9 calories per gram, fat has more than twice the energy density of protein or carbohydrate. Rather than being a reason to reduce fat in the diet, this fact may be a clue to what studies have shown: a higher fat diet satisfies hunger faster than a high carbohydrate diet.

In the wild, given plenty of their natural food, all mammals assume a strikingly familiar profile. All well nourished wild cats appear about the same to other cats in their age group. Coyotes, feasting on rodents and other small animals, all look about the same. They don’t suffer from the obesity of their domestic canine cousins, who are fed unnatural diets by humans, or their brothers and sisters held in captivity. They have adapted to their natural diet, and even if they overeat on occasion, such as after a big kill, they don’t seem to gain weight.

Fat’s energy density may be the reason it is more satisfying, curbing hunger sooner than other foods. Mankind’s long evolutionary history of eating fat-rich food may have adapted us to be satisfied with a smaller amount of fat-rich food.

But hold on … science may have given us an answer as to why low carb diets are often said to have a “metabolic advantage”.

The Most Recent Study

The most recent study I have found is one in which six men, between the ages of 18 and 40, were tested to see how a low fat and a high fat diet affected lipolysis of their abdominal fat tissue. Lipolysis is the breakdown and use of fat as energy by the body. For overweight people, getting the body to “burn fat” is the usual goal.

There’s a reason studies like this one segment the subjects so specifically. Men with still-high levels of testosterone like this group may react differently than men over 50, who may have lower levels. Testosterone aids in lipolysis, which is one reason all those young guys at the gym seem to have such rapid progress. And its one reason that women in general and men over 50 have a harder time losing weight.

Only Six Particpants?

At first glance, having only six participants in a study may make it seem insignificant. But this study is different from the cohort studies that track a large population over a period of time and draw correlations from the data. Many of the dietary studies we see are prospective or cohort studies, or even meta-analysis of multiple cohort studies. The purpose of a cohort study is to identify trends, and develop a hypothesis that can be tested in a specific study like this one. So, in this case, having six participants in a direct study is actually more indicative of what really happens to individuals than a cohort study with hundreds or thousands of participants. In this type of study, unlike in the cohort study, specific measurements are taken at specific times of known people.

What Was Measured?

The study, Increased adipose tissue lipolysis after a 2-week high-fat diet in sedentary overweight/obese men, set out to determine if a high-fat diet affected the rate of “fat burning” in the six men. How do you measure the amount of body fat that has been burned? The most accurate way is to measure one of the by-products of lipolysis, glycerol, in the small amount of fluid that surrounds each cell (called the “interstitial fluid”). The more glycerol present, the more fat tissue has been broken down and used by the body as fuel.

The men adopted a high fat diet for two weeks, and had the interstitial glycerol measured. Then they ate their normal diets for 10 days. After this “washout period”, they ate a “well-balanced” diet with the same number of calories. A “well balanced diet” is usually code for a diet such as the USDA recommends, with high carbohydrate levels. After two weeks, the interstitial glycerol was measured.

Note that this method corrects for differences in calorie intake. Both diets were composed of the same number of calories, or were “isocaloric” in dietary study parlance.

Average interstitial glycerol concentrations (index of lipolysis) as determined using microdialysis were higher after the high-fat diet (210.8 ± 27.9 μmol/L) than after a well-balanced diet (175.6 ± 23.3 μmol/L; P = .026).

Not only did eating fat NOT make the men fatter, it actually increased the rate of fat burning by 20%.

Is This The Answer?

Hold on, grasshopper. This study does show that the fat cells release more fat on a “high fat” (and therefore lower carbohydrate) diet. But that’s all it measured. Is it possible that a high fat diet could lead to more storage of fat elsewhere? They don’t know:

These results demonstrate that healthy nonlean men who diet on the high-fat plan have a higher lipolytic rate in subcutaneous abdominal adipose tissue than when they diet on a well-balanced diet plan. This higher rate of lipolysis may result in a higher rate of fat mass loss on the high-fat diet; however, it remains to be determined if this higher lipolytic rate in men on the high-fat diet results in a more rapid net loss of triglyceride from the abdominal adipose depots, or if the higher lipolytic rate is counteracted by an increased rate of lipid storage.

I suspect that last sentence is being used to request more funds for another study!

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.

RD Turn-About: Fat Not So Bad

The American Dietetic Association is a low fat bastion, with member dietitians rarely advising patients to embrace a low-carb lifestyle. Doctors routinely refer their patients to Registered Dietitians for guidance, and their advice is normally horrendous. So it was with great interest that I read the news item regarding a presentation at the American Dietetic Association’s (ADA) Food and Nutrition Conference and Expo this month (November, 2010). From a news story in Food Navigator USA:

During a symposium called “The Great Fat Debate: Is There Validity In the Age-Old Dietary Guidance?” at the American Dietetic Association’s (ADA) Food and Nutrition Conference and Expo, four leading experts presented evidence suggesting that low fat diets may be less healthy than those containing at least a moderate amount of fat. In particular, all four agreed that replacing saturated fat with carbohydrates – as has been widely recommended in the United States – is likely to raise the risk of cardiovascular disease.

Emphasis mine. Just thought I’d bold that statement in case any deaf Dietitians were in attendance.

It is not that this is “new news”. The evidence has been mounting, and Low Carb Age has been documenting the end of the low fat diet craze for over a year now. But to have the ADA admit it is a very big deal indeed.

Just to recap some stories in the past year:

Dietary intakes of saturated fats are not linked to cardiovascular disease, so says a meta-analysis of 21 studies from across the world.

Data from almost 350,000 subjects obtained from 21 studies indicated that dietary intakes of saturated fat are not associated with increases in the risk of either coronary heart disease (CHD) or cardiovascular disease (CVD), US researchers report in the American Journal of Clinical Nutrition.

“Our meta-analysis showed that there is insufficient evidence from prospective epidemiologic studies to conclude that dietary saturated fat is associated with an increased risk of CHD, stroke, or CVD,” wrote the researchers, led by Dr Ronald Krauss from the Children’s Hospital Oakland Research Institute in California.

Japanese researchers noted an increase in mortality – that means death, folks – from strokes in those that adopted a low fat diet:

Very low intakes of saturated fats may be just as bad for you as very high intakes, and could lead to an increased risk of death from stroke – according to new Japanese research.

The study, published by the American Journal of Clinical Nutrition, suggests that a very low dietary intake of saturated fatty acids (SFA) is associated with an increased risk of stroke.

“SFA [saturated fatty acids – saturated fat] intake was inversely associated with mortality from stroke. This inverse association was similarly observed for intraparenchymal hemorrhage and ischemic stroke,” wrote the researchers.

Some of the stories show the conflicted nature of researchers facing unpleasant results. One study looked at low fat diets and concluded that it was the type of carbohydrates in the diet that were at fault:

People who cut saturated fats while increasing intake of refined carbohydrates like white bread and pasta have a higher risk of heart attack, according to a study published in the American Journal of Clinical Nutrition.

However, the Danish researchers found that reducing saturated fats while increasing intake of non-refined carbohydrates – such as wholegrain bread and vegetables – could improve heart health. A recent meta-analysis published in the same journal earlier this year called into doubt the widely held theory that high saturated fat intake is linked to high rates of heart disease – but the researchers behind that review said that other dietary elements of the 350,000 subjects involved could be more important.

. . .

They found a statistically significant correlation between replacing saturated fat calories with refined carbohydrates – those described as ‘high-GI’ and thought to cause a spike in blood sugar levels – and heart attack risk. For those subjects with the highest average dietary glycemic index, heart attack risk increased by 33 percent for every five percent increase in calorie intake from carbohydrates.

See the disconnect? I have emphasized the pertinent passage. They are still preaching the “whole grain breads” line while simultaneously saying that High Glycemic Index (GI) foods should be avoided. Yet whole grain bread often has a higher GI than plain old white bread (average of 62 vs. 59). You can see the official GI of different foods at http://www.glycemicindex.com/

Not that the gycemic index should really be a guide. For most Americans, cutting out refined carbs, including all breads, cookies, muffins and cakes, would go a long way toward curing the obesity problem in this country. Whole wheat and whole grain breads are still refined carbs, and spike blood sugar. Wheat may be implicated in numerous health issues due to allergies and sensitivities, sometimes hidden behind nebulous diagnoses of Chronic Fatigue Syndrome or PCOS.

Following a true low carb lifestyle, or adopting a paleo outlook to eating, would greatly enhance health while avoiding the hunger that plagues low fat dieters, and may clear up other health issues (as I found with eliminating GERD and insomnia).

Welcome to the club, dietitians!

Twilight Zone of Diet Studies

Imagine if you will a diet study, a seemingly ordinary diet study. One that compares low carb and low fat diets. Now imagine that you are reading the results, and find the unequivocal superiority of the low carb diet.

Results:

Both the Low and Moderate Carbohydrate groups lost significantly more weight as well as inches from their waists and thighs than the Control group, while the Low Carbohydrate group lost a greater percentage of body fat. Although the Moderate Carbohydrate group showed significant reductions in serum cholesterol, the Low Carbohydrate group showed the greatest improvements in serum cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, and very-low-density lipoprotein.

Consider, if you will, how you would write the conclusion to these findings. That all-important snippet of text that will be read by those too busy to read the full synopsis, the snippet that will be picked up in articles and future studies.

Perhaps you will write something that bears some resemblance to the words and phrases in the Conclusion. Something that recognizes the low carb diet as being at least equal in your test for weight loss, yet reducing more body fat than the low fat diet. Consider how you will sum up the findings, that the low carb diet provided significantly better results for cholesterol and triglycerides. But before you put your pen to paper, read the actual conclusion:

Moderate approaches to weight loss such as a moderate-carbohydrate low-fat diet may be prudent.

There is nothing wrong with your eyes. Those are the words the study authors penned. An example, perhaps of cognitive dissonance.

You are traveling through another dimension –a dimension not only of sight and sound but of mind. A journey into a wondrous land whose boundaries are that of imagination. That’s a signpost up ahead: your next stop: the Twilight Zone of Diet Studies!

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 LowCarbDaily.com, 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.

Dr. Weil’s Evolving Dietary Standards

Dr. Andrew Weil is a well known physician and author, the founder of the field of integrative medicine, a discipline that marries alternative forms of medicine for health preservation and maintenance, yet recognizes the value of traditional western medicine for crisis intervention.

Because of his focus on health and his willingness to use “regular” medicine when needed, Dr. Weil has the ear of many alternative medicine devotees. They trust him because while he respects western medicine, he doesn’t dismiss alternative medicine out of hand.

Dr. Weil advocates lowering carbs in the American diet in a recent article. His foil for the article is the “Heart Attack Grill“, a Chandler, AZ restaurant that features large hamburgers with cheese:

Now, there is much for a medical doctor (as opposed to “Dr. Jon,” the stethoscope-wearing, burger-flipping owner) to dislike in this establishment. If you visit, I implore you to steer clear of the white-flour buns, the sugary sodas and the piles of “flatliner fries” that accompany the burgers in the restaurant’s signature bedpan plates. This is precisely the sort of processed-carbohydrate-intensive meal that, via this and other fast-food establishments, is propelling the epidemic of obesity and diabetes in America.

But the Grill’s essential, in-your-face concept is that the saturated fat in beef clogs arteries, and hamburger meat is consequently among the most heart-damaging foods a human being can consume. As the Grill literature puts it, “The menu names imply coronary bypass surgery, and refer to the danger of developing atherosclerosis from the food’s high proportion of saturated fat…” Aimed at a certain crowd, this is clever, edgy marketing. Some people enjoy flirting with death.

The problem? It’s not true. The saturated fat lauded in this menu won’t kill you. It may even be the safest element of the meal.

Dr. Weil goes on to cite the meta-analysis of 21 studies covering 348,000 participants that showed no association between saturated fat intake and coronary or cardiovascular heart disease. Published in the respected American Journal of Clinical Nutrition, Dr. Weil notes that it is not a “true study” but rather a review of those 21 other studies. The study notes no correlation between a high saturated fat diet and increased heart disease or stroke:

This contradicts nutritional dogma we’ve heard repeated since 1970, when a physiologist named Ancel Keys published his “Seven Countries” study that showed animal fat consumption strongly predicted heart attack risk. His conclusions influenced US dietary guidelines for decades to come, but other researchers pointed out that if 21 other countries had been included in that study, the association that Keys observed would have been seen as extremely weak.

Although his article has been touted in the low carb blogosphere, Dr. Weil is not an Atkins, Protein Power, paleo or meat centric diet advocate. Far from it; he still emphasizes a anti-inflammatory diet pyramid that is the antithesis of a low carb lifestyle, with whole grains, pasta and legumes just above fresh fruit and vegetables in importance. “Lean meats” are to be enjoyed at a frequency of only 1 to 2 servings per week.

His diet recommendations are evolving, but still have a long way to go. Three to five servings per day of “whole or cracked grains” is still too carb rich for those with insulin resistance, metabolic syndrome or type II diabetes (or other “fat people”).

Dr. Weil may be able to tell you that the bun is the worst part of the hamburger, but he hasn’t come to terms yet with the evolutionary imperative of our ideal diet.