Rule Three: Vegetables & Fruits are Heart of Controlled-Carb

We hear much of a healthy diet is from eating fruits and vegetables. Research suggests there is a strong correlation between "good" health and "bad" health over the long-term when comparing the dietary habits of those eating a diet rich with fruits and vegetables to those consuming less than recommended levels.

Diets that strategically restrict carbohydrate are often criticized for lack of fruits and vegetables in the dietary approach. Much like the second rule getting lost in translation, from an allowance of a large variety of meats, poultry, fish, shellfish and game to a requirement to eat "fatty steaks, bacon, brie and cheeseburgers," by those unconvinced a low-carb diet is scientifically supported, rule three is often either ignored in the media and/or used to show how unsustainable carbohydrate restriction is in the long-term for someone to do forever.

How about we take a look, and see what the third rule actually says, and what it "pearls" it contains in both the short and long-term, and where vagueness may lead to misinterpretation:

Rule 3:

• Eat no more than 20 grams a day of carbohydrate, most of which must come in the form of salad greens and other vegetables. You can eat approximately three loosely packed cups of salad, or two cups of salad plus one cup of other vegetables.

First, we know from the published books, that the Induction period is a minimum of two weeks; while one can, and many do, stay within the 20g of carbohydrate beyond two weeks, the above rule is in place for at least the first two weeks.

During this time, the person starting the low-carb diet is tasked with two things in this rule:

1. limiting carbohydrate to just 20g a day and
2. ensuring that most of those 20g carbs are from salad greens and other (allowed) vegetables.

As an example, the rule says this is "approximately" three loosely packed cups of "salad" (note not simply salad greens), or two cups of "salad" (again not simply salad greens) plus one cup of other (allowed) vegetables (without mention of raw or cooked state).

We also know that the plan includes a deduction of fiber, so the amount of non-starchy vegetables (and fruits which I'll get to in an upcoming post) - in cups - that one is expected to consume depends highly on which allowed vegetables are selected in a day. Regardless of which are included, a minimum 10g net (deducting fiber) must come from non-starchy vegetables!

We also plainly see that it is not *mandatory* to deduct fiber per the rule above; however, I strongly suggest folks do deduct fiber as it allows a greater intake of non-starchy vegetables, which are not only low in calories, but nutrient powerhouses. When you deduct the fiber, you're able to consume more essential nutrients than if you don't.

I've previously offered examples of how different selections of non-starchy vegetables may look in a day of eating on a plan allowing 20g net in a day. Once again, I am providing examples to emphasize, even at 20g net carbohydrate, where 10g net is the minimum, a low-carb plan - done properly - meets or exceeds intake recommendation of at least five servings per day in the Dietary Recommendations for Americans for fruits and vegetables.

Example 1

• 1-cup green beans (cooked measure)
• 2-cups Shredded Cos/Romaine Lettuce (raw)
• 4-pieces Crimini Mushrooms (raw)
• 1/4-cup Shredded Red Cabbage (raw)
• 4 Cherry Tomatoes (raw)
• 1-cup Spinach (raw)
• Total Carbohydrate = 18g
• Fiber = 8g
• Net Carbohydrate = 10g
• USDA Servings of fruits/vegetables = 5

Example 2

• 1/2 Avocado (raw)
• 3-cups Cos/Romaine Lettuce (raw)
• 4 Cherry Tomatoes (raw)
• 1/4 cup Shredded Red Cabbage (raw)
• 1-cup Spinach (cooked measure)
• 1/2-cup Broccoli Florets (raw)
• 1/2-cup Sliced Cucumber (raw)
• Total Carbohydrate = 24g
• Fiber = 14g
• Net Carbs = 10g
• USDA Servings of fruits/vegetables = 6

Example 3

• 2-cups Shredded Cos/Romaine Lettuce (raw)
• 1/2-cup Cherry Tomatoes (raw)
• 1-cup Spinach (cooked measure)
• 1/2-cup Asparagus (cooked measure)
• 1/2 cup Sweet Green Peppers (cooked measure)
• Total Carbohydrate = 21g
• Fiber = 9g
• Net Carbs = 12g
• USDA Servings of fruits/vegetables = 6

One can see from the examples above, depending on selections made from those fruits and vegetables allowed in the first two weeks, it is not difficult to meet the recommended intake of 5-or-more servings of fruits and vegatables.

The aim to include a minimum of 10g (of the 20g allowed) from non-starchy vegetables is a "must" in the rule above.

It is also clearly stated as a "minimum," and therefore understood that if you would like to include 12g, 15g or more from non-starchy vegetables in lieu of other foods that have carbohydrate, that is also allowed.

So, if one is cognizant of and desiring more than the minimum intake of fruits and vegetables, they are completely allowed to consume more - with the only restriction being not to exceed 20g net (deducting fiber) during the first two weeks.

Must you aim to consume half your allowed carbohydrate from fruits/vegetables? YES

Can you eat more fruits/vegetables (allowed ones), say 12g, 15g, 18g? YES

Can you deduct fiber? YES

Do you have to? NO (but doing so allows a greater intake of fruits/vegetables and associated essential nutrients)

With all that said, and focus on what all the rules mean for the long-term, I contend that one is expected to continue eating this level (as minimum each day) as they progress toward the long-term eating. I believe that this is one more "foundational" part of carbohydrate restricted diets in the long-term and something intended to be continued as one increases carbohydrate and includes a wider selection of foods, including more vegetables, fruits, nuts, seeds, legumes, and if desired, even whole grains.

Many folks say a low/controlled-carb diet is a way of life, yet find it difficult to take what they start with - 20g net (deducting fiber), of which most must be provided by non-starchy vegetables, a 10g minimum each day - and maintain that aspect as one solid foundation to build upon as they continue to lose weight and then maintain their weight.

Old eating habits start to creep back with more carbs; habits such as preferrentially selecting sweeter foods or grains (even if whole grain) with consumption of non-starchy vegetables waning as one re-introduces more carbohydrate.

If one takes this rule, and continues to extend it --- fully --- until they reach 40g net carbohydrate each day (deducting fiber), they will be consuming incredibly healthful levels of fruits and vegetables, and will be able to eat a very wide variety of them too. That is, until 40g carbohydrate is achieved in the diet during weight loss, one must always include half those carbohydrates from fruits and vegetables with each incremental increase in carbohydrate. (Beyond that, it is increasingly difficult to continue adding more non-starchy vegetables and fruits due to their bulk; you can, of course - it's just not as easy to do).

Now that isn't exactly stated explicitly in the rule, but it is from my experience and those I've given assistance, one significant contributor to maintenance of weight in the long-term. That's because if you're aware of and including a lot of fruits and vegetables (specifically non-starchy vegetables and low-glycemic load fruits) it is difficult to consume excess calories each day over the long-term.

It becomes much easier to consume excess calories when you "play" the carb game (like many play the "points" game with Weight Watchers) and make choices to stay within a number, rather than focus on quality of choice.

But if you're committed to making sure that, no matter what intake of carbohydrate you reach (60g, 90, 120g or more), that you always are sure you include at least 10g net minimum at the start and then 20g minimum (net) from non-starchy vegetables/low glycemic-load fruits as you continue along, you'll have a favorable calorie intake that helps maintaining weight easier.

As you add back carbs, this rule must remain in your eating habits, even if you only stick with 10g net as minimum (which I don't suggest you do) as you're learning in the beginning - you cannot add back carbs and eliminate or reduce how many vegetables and salads you eat each day and expect to maintain your weight using grains, nuts, fruits, etc. as your primary source of carbohydrate later....you must always maintain a level of carbs from your vegetables and salad greens - even in maintenace.

This rule, like rule two, is taking you "back to basics" - helping you learn, step-by-step, how to nourish your body with high quality nutrients from real foods; over time you're encouraged to include a wider variety of non-starchy vegetables, low glycemic-load fruits, nuts, seeds, legumes and more, and the starting basics for the diet should be extended out for the long-term; that is, establish now, at the start, that as part of your long-term habitual diet, non-starchy vegetables and low-GL fruits will be a large part of your overall diet - your body will thank you!

Rule Two: Back to Basics

Over the last few decades, the population at large, has slowly been indoctrinated to fear dietary fat; to limit intake of dietary cholesterol; and to limit consumption of foods rich with saturated fat like meat, whole dairy, butter and eggs. This happened despite little evidence that such an approach to eating provided a long-term health benefit, or ability to maintain weight. But, with decades of reinforcement in the popular thinking, it's understandable how the second rule in the Rules of Induction is the most misunderstood and maligned of them all.

Let's take a look:

Rule 2:

• Eat liberally of combinations of fat and protein in the form of poultry, fish, shellfish, eggs and red meat, as well as pure, natural fat in the form of butter, mayonnaise, olive oil, safflower, sunflower and other vegetable oils (preferably expeller-pressed or cold-pressed).

Is it any wonder that, when a diet comes along and allows these foods, in complete contradiction to decades of fat phobia propoganda, it is vehemently opposed by the leading health organizations and government agencies? That we're innundated with dire warnings of consequence to health, heaped upon us in a concerted effort to discredit and dismiss anyone who says differently; despite scientific evidence and data supporting not only the inclusion of these foods in the human diet, but their inportant contributions to the human diet!

Ignore the man behind the curtain Dorothy....ignore that in the noble attempts to improve the health of our population, researchers and clinicians were lead astray by what we now know was half-truth data, published in the fifties and sixties.

They know it, we know it, but still it's difficult to come to grips with that fact and reverse direction after decades of building the foundation of a "truth" only to find it terribly flawed. It's often easier to continue on in the lie than face the fact you're wrong; moreso when the entire group and community you exist within endorses the continuation of the established dogma, despite the evidence to the contrary.

It's easier to "kill the messenger" than kill the flawed paradigm that hold these foods are to be limited, heck, even avoided at all cost.

To admit such is akin to killing thyself and the core set of beliefs one holds to be true.

Dramatic license here?

Sure, but it does speak of something critically important one must do for their long-term health when they begin to, perhaps for the first time in their life, establish good eating habits for the rest of their life.

Simply put, the second rule of induction grants us permission to dismiss everything we've been told and taught to hold as truth about eating, macronutrients (carbohydrate, protein, fat) and a "balanced, healthy" diet; allows us to re-learn what it means to be human and eat food; and encourages us to enjoy the experience of truly eating a healthy diet while losing weight and then continue to do so along the way to finally, once and for all, maintain that weight well into the future.

I'm quite the optimist aren't I?

Seriously, don't studies tell us again and again that dieting to lose weight fails, that all we really ever do is get good at losing weight, but we're never quite able to master maintaining our weight in the long-term?

Let's start by examining the very base reason most folks even begin a diet to lose weight - they're overweight or obese and have decided it's time to do something about it.

So they begin, they are off to a good start, they're motivated and continue to be motivated with each incremental decline they see on the scale.

Problem?

Absolutely - the focus is on the scale; the number on the scale matters most and damn the torpedos, no matter how inconvenient, stressful or annoying it is to weigh, measure and count every calorie, the individual is in a battle against their bathroom scale to reach a desired number in the shortest period of time possible.

Millions have mastered this task, only to have to repeat it again and again throughout their life. I apolgize now if this sounds crass, but anyone can lose weight with even just a small level of effort; it doesn't take an Einstein to eat less for weeks or months to reach a number on the scale; most will put up with high levels of discomfort to reach that goal - hunger, moodiness, irritability, stress and counting, measuring and weighing anything they consider putting in their mouth.

In the short-term, such measures do work; in the long-term they fail because the person has been mistakenly led to believe "if only..." they do this, measure that, control this and avoid that over the short-term, somehow that alone will enable them to maintain their new lower weight without much more than keeping on keeping on; except the keeping on part is next to impossible!

That's because the very dogmatic recommendations we're repeatedly told are balanced and healthy to lose weight are scaring people away from the very foods that we need to eat to thrive as humans; this forces an unnatural eating patten across the population due to a deeply flawed fear of dietary fat and cholesterol and leads to failure in the long-term because it is not only unsustainable, it's incompatible with true health in the longer term.

The heart and soul of our metabolism is the endocrine system - when it dysfunctions, a cascade of health problems follow - insulin resistance, high blood pressure, dyslipidemia, diabetes, and other chronic and debhilitating diseases.

Why then are we specifically told to avoid the very foods that fuel the proper function of this system?

The current recommendations not only scare us from healthy food, they make simply eating way too stressful for an average person - measure this, weigh that, watch this, avoid that, don't eat this, that's better, blah, blah, blah - who wants to deal with that much stress each day? Sure, a motivated person, desiring weight loss will submit to such stress to reach a goal - but then what happens? They do what is natural and human - they do what they need to do to relieve the stress and relax, are then an easy target to point to as someone lacking willpower, someone just not commited to sticking with it; someone who simply doesn't care and is lazy!

Anyone who has attempted to lose weight only to regain it can relate - no matter how hard you try to stick with a diet that is, for lack of a better phrase, "high maintenance" to follow each day for the rest of your life - sooner or later you find the "benefit" (weight on scale) isn't worth the time and "stress" (weighing, measuring, going hungry, chastising yourself for wanting to eat, etc.).

As I said in my last post, what if the problem isn't you or your "willpower," but a deep flaw within the recommendations that lead not to success, but failure in the long-term?

Here's the rule again:

Rule 2:

• Eat liberally of combinations of fat and protein in the form of poultry, fish, shellfish, eggs and red meat, as well as pure, natural fat in the form of butter, mayonnaise, olive oil, safflower, sunflower and other vegetable oils (preferably expeller-pressed or cold-pressed).

The short and long-term secrets within this rule include:

1. Eating "liberally" is not the same as eating until you are stuffed and goes hand-in-hand with rule 6, which we'll look at later this week. This rule is also a natural extention to rule 1 to eat regular sized portions.

2. You're allowed to eat animal foods such as meats, poultry, fish and eggs provides you with combinations of both fats and protein - necessary for health, losing and maintaining weight on a carbohydrate restricted diet.

Note that in the rule, no one is told they must eat "fatty meats" or must consume "bacon, brie and oodles of t-bone steaks." No, instead they're to eat foods that provide both fat and protein; they can choose whatever cuts they like, whatever combinations suit their tastes; whatever they prefer.

Want boneless skinless chicken breast? Allowed.

Want a filet mignon? Allowed.

Want some eggs? Allowed.

Want some dark turkey meat? Allowed

Want some salmon? Allowed.

This "allowance" of all things that provide a good fat-protein combination reinforces our mindfullness not to fear food, food is not the enemy!

Adding to this is that using fats and/or oils as part of your meals is allowed - from sources of natural, good fats and oils; with those natual oils being preferentially from expeller-pressed or cold-pressed sources.

Why are the animal products with combinations of fat and protein and the use of natural fats & oils so important?

By integrating both into your meals you are also beginning the process of balancing your essential fatty acid ratios in your eating from the fats found in these sources, and perhaps for the first time, consuming adequate protein, thus adequate essential amino acids.

Important too is to choose quality, eat well and enjoy your food and meals. Don't worry each day about how much fat is in a particular food or meal at this stage, over time you'll be able to "tweak" as you go and learn better how to nourish your body and eat what really is a well-balanced, healthy diet.

With fat and protein providing the vast majority of "essential" nutrients, this liberal approach at the start of your weight loss diet takes you "back to basics" and with time, provides you the opportunity to not only learn how to eat well for the long-term, but to actually enjoy your meals again - without fear that you're killing yourself with every bite!

Back to Our Regularly Scheduled Program

You may recall the alarming headlines reported here that suggested a high-fat meal was very risky to endothelial function; one went so far as to suggest just one bite of a burger might kill you!

Seems some researchers thought maybe it's a good idea to see what effect a high-protein (low-carb) and low-fat (high-carb) habitual diet might have on endothelial function over a longer period of time - say, maybe a year?

Wonder why you haven't seen any headlines on the latest study - Effects of weight loss on a low-carbohydrate diet on flow-mediated dilatation, adhesion molecules and adiponectin - published in the British Journal of Nutrition?

Might be because the researchers found nothing significantly different between the two diets, and noted "weight loss does not improve FMD [flow mediated dialation]."

Paper gets published, media sees it, notes noting to see here, no sexy headlines....not quite juicy enough to waste readers time with (even though it contradicts those one-meal experiements), so let's just move on.

But wait!

Just because the study objective was to see effect (benefit or risk) on FMD, adhesion molecules and adiponectin, was there anything else they measured that did have significance and is worthy of our time to look at?

How about we take a look?

Two groups of subjects were randomized into two different dietary protocols - the first included 13 people assigned a low-carbohydrate diet (40% protein, 27% carbohydrate and 33% fat; 26g fiber daily); the second included 12 people assigned the high-carb diet (20% protein, 60% carbohydrate, 20% fat; 40g fiber daily).

Both groups were weighed, measured, poked and prodded and followed up with a 6-weeks, 12-weeks and 52-weeks. Measurements and testing included weight, BMI, blood pressure, cholesterol, glucose, insulin, CRP, VCAM1, sICAM1, E-selectin, P-selectin, and total adiponectin. In addition, vascular measurements were taken for blood pressure analysis and endothelium-dependent FMD, along with an assortment of other tests.

The various measurements were duly recorded for baseline and re-measured during follow-ups, and were included in the final paper. Some critically important measures were statistically significant, but not the focus of the study design; thus not highlighted in the abstract conclusions.

We hear a lot about how low-carb diets are bad for cholesterol.

In this study, like others, total cholesterol, LDL and triglycerides were lowered over the course of the year and HDL rose while following the low-carb diet.

Total Cholesterol:
Baseline = 5.3
52-weeks = 4.62
[low-fat group went from 5.7 to 4.94]

LDL:
Baseline = 3.5
52-weeks = 2.69
[low-fat group went from 3.8 to 3.07]

HDL:
Baseline = 1.3
52-weeks = 1.44
[low-fat group went from 1.3 to 1.34]

Triglycerides:
Baseline = 1.7
52-weeks = 1.07
[low-fat group went from 1.4 to 1.34]

Intriguing too was the improvements with glucose and insulin following the low-carb diet:

Glucose (fasting):
Baseline = 5.9
52-weeks = 5.19
[low-fat group went from 5.8 to 5.5]

Insulin (fasting):
Baseline = 16.9
52-weeks = 7.28
[low-fat group went from 12.1 to 5.22]

An interesting finding was that adiponectin, a hormone involved in a number of metabolic processes, including glucose regulation and fatty acid catabolism, "did not change significantly after 12 weeks of weight loss" (p=0.10), but increased (good) at the last measurement, 52-weeks, at the end of the study (p=0.05).

Blood pressure (not high at baseline) improved, from 122/75 at baseline to 115/68 at the 52-week measure; for those on the low-fat diet, blood pressure increased from 122/75 at baseline to 130/74 at 52-weeks.

It's clear in the data that both dietary approaches offered improvements with weight loss in the above measures of risk factors. Something though wasn't "right" to help with, improve, endothelial-dependent FMD. We'll explore potentials in a moment.

Somethign troubling that seems glossed over - the higher blood pressure in those following the low-fat diet - where at baseline their blood pressure averaged 122/75, at 6-weeks it improved to 115/72 and again improved at 12-weeks was similar at 118/70. What happened between the 12-week measure and the blood pressure reading at week 52, when blood pressure was now averaging 130/74?

This is something I would consider worthy of noting, even maybe point out and suggesting additional questions and investigation as to why!

In the discussion section, the researchers stated that "The main finding of the present study was that weight loss on a low-carbohydrate diet which brought about reductions in glucose, insulin and LDL-C did not improve FMD either after short-term weight loss or long-term weight maintenance. Irrespective of diet composition weight loss had beneficial effects in the short term on adhesion molecules and blood pressure and in the longer term on adiponectin and P-selectin. There appears to be a delay in improvement in both adiponectina nd P-selection as these molecules did not improve until weight loss had been maintained for a year."

They went on to add, "Lack of change in FMD in the present study confirms our previous finding that weight loss does not improve FMD...One of our goals with the dietary intervetion was a reduction in LDL-C which we achieves, 18% at 6-weeks and nearly 30% at the end of the study with no effect on FMD."

The researchers also noted that "The present study was also designed to achive a reduction in glucose in a 6-week weight loss intervention on a more moderate diet of 6000kJ and we achieved this but with no effect on FMD."

And, "A complex physiological response such as FMD may be related to LDL and glucose cross-sectionally and in post hoc analyses but these may not be casually related but correlate in some circumstances with the real unmeasured mediator of change. For instance, oxidative stress may be a major factor in reducing NO bioactivity but reducing LDL levels may have no effect on this even though the endothielial cell is clearly heathier as judged by a reduced adhesion molecules."

In the end, they concluded that "weight loss on a low-carbohydrate, low-saturated fat diet, does not improve FMD despite improvement in cardiovascular risk factors. The improvement in adiponectin was delayed."

So what was their error of omission?

Well, for one they failed to note the problematic rise in blood pressure observed in the subjects following the low-fat diet. But, let's set that aside for a moment.

They also failed to note that the above failure to improve FMD was also observed in subjects following the low-fat diet; one that happened to be designed well enough to match the American Heart Association recommendations!

Yet even that low-fat diet (20% of calories from fat) didn't help improve FMD, despite their weight loss, improvement in glucose, insulin and cholesterol; but this was left unsaid.

I'm not surprised.

So, what we're left with is the stated null finding of those on the low-carb diet, with no real statement that neither dietary approach did much for FMD.

I hate to say it, but there was also a lack of curiosity as to why this was.

It's pretty much accepted dogma that a low-fat diet improves the cardiovascular system, thus would exert a postive - significant - effect on endothelial-dependent FMD. It didn't, yet the researchers didn't say "hey, wait, this low-fat diet didn't help either" and instead highlighted that the low-carb diet didn't improve FMD in their conclusions.

Some questions really do need to be asked.

First, how did the low-carb diet look compared with the habitual diet?

We know subjects were consuming, on average, 11.4mJ each day (2725-calories) as their habitual diet. The weight loss diet was 6000kJ each day (1430-calories). They followed the weight loss phase of the diet for six weeks and lost 5.8kg, or 12.75-pounds.

Let's do math!

Each day, we're to believe, the subjects were in a calorie deficit of 1295-calories. Six weeks is 42-days, so over the period, a calorie deficit of 54,390 calories - enough to theoretically lose 15.5-pounds. Hmmm....Okay, so it's pretty clear they did not really follow the diet as planned, since it's clear they consumed more calories than was reported. Happens all the time, no biggie.

Except, we have no idea what the excess calories were, so we have a confounding variable here. Did they eat pie? Did they eat broccoli? Did they eat fatty meat instead of lean meat? Did they skip the oatmeal and eat eggs? Who knows?

It's also noteworthy that the low-fat dieters ate a habitual diet of 10.8mJ daily (2581-calories) and were placed on the same weight loss calorie level. So they were in a calorie deficit of 1150-calories each day, or a six week deficit of 48,342-calories. This theoretically would result in a weight loss of 13.8-pounds; they lost 5.9kg (13-pounds). Did they cheat less? Did they stick to the diet more carefully? Who knows?

But, we can be sure we have a confounding variable here - something doesn't add up, and it looks like that something is calorie intake. It appears it was higher than the dietary protocol called for; and an increased calorie intake we have no idea what foods/macronutrients it came from.

So then, is there anything else? Let's see how macronutrient intake changed on the low-carb diet.

At baseline, their habitual diet - 2725-calories - was from 39.6% carbohydrate (270g), 19.6% protein (133.5g) and 36.5% fat (110.5g). We do not know the baseline intake for fatty acids, but do know the dietary protocol was strict - saturated fat 7%, PUFA 6% and MUFA 13% of calories.So, while following the weight loss diet, the macronutrient profile changed to provide 1430-calories each day, of which 33% were carbohydrate (118g), 40% protein (143g) and 27% fat (43g) with 7% from saturated fat (11.1g), 6% from polyunsaturated fat (9.5g) and 13% from monounsaturated fat (20.7g).

The first glaring disparity is the protein-to-fat intake, for every 1g of fat, they were expected to consume 3.3g of protein; this is a highly unusual pattern, heavy with protein and too lean - if you review other studies on "low-carb" diets, the fat intake is usually higher than the level in this protocol and protein typically lower; of note, this intake ratio is next to impossible without some funky planning. I'd like to know how much soy was a part of this diet? How much of the diet was comprised of non-fat dairy? How much fish was allowed, and what type was it? Were protein shakes or supplements part of the protocol? If so, which type of isolate dominated?

Without this specific data, it's difficult to say one way or another if the foods included may have contributed to the null finding or not.

So here, we have a potential confounding variable that is unexplored.

Anything else?

Well, from the data we do know, it seems we find an inadequate level of polyunsaturated fats - with just 9.5g each day; a level at which the subjects are unable to meet essential requirements for omega-6 or omega-3 fatty acids!

I am really starting to wonder why researchers designing diet protocols that are inadequate for known essential nutrients?

The Institute of Medicine (IOM) clearly states in the Daily Recommended Intake documentation, the MINIMUM required each day from omega-6 is 5% to 10% of calories and the MINIMUM requirement each day from omega-3 is 0.5% to 1% - when calories are adequate to maintain weight. In absolute terms - absolute gram minimums - the IOM states that adequate intake of omega-6 fatty acid is 14g-17g for men (depending on age) and 11g-12g for women (depending on age); and that adequate intake of omega-3 fatty acids is 1.6g for men and 1.1g for women.

Combined, the absolute minimum intake for essential fatty acids is between 15.6g-17.6g for men and 12.1g-13.1g for women.

In this study, even if every last gram of polyunsaturated fat was an omega-3 or omega-6, these subjects were deficient for essential fatty acids with only 9.5g of polyunsaturated fats as part of the diet.

So, again, confounding variable - huge confounding variable!

And the researchers question why the diet didn't have an effect on FMD?

Perhaps the researchers haven't read the data showing improvement in cardiovascular health when essential fatty acid intake is optimized to meet or exceed current recommendations?

Recent evidence of the role of omega-3 polyunsaturated fatty acids on blood pressure control and hypertension-related complications

Omega-3 Fatty Acids: Role in Cardiovascular Health and Disease

Fish Oil and Endothelial Function

I can't say it enough - I love good data, but studies like this, with macronutrient intakes, as percentage of calories, is highly confounded data. Designing a dietary approach to lose weight or maintain weight, macronutrient percentages are often inefficient and do not meet essential nutrient requirements.

I'd really like to see some researchers start designing studies to ensure adequate intake of essential nutrients within the calorie deficits - until we start to look at the nutrient-quality of weight loss diets, I'm afraid we're not going to make much progress to provide the public with sound, scientifically supported recommendations.

The Devil in the Details - Low-Carb High Protein Diet Kills

A study - Low-carbohydrate–high-protein diet and long-term survival in a general population cohort - published in the May edition of the European Journal of Clinical Nutrition (originally available ahead of print, November 2006), concluded that "Prolonged consumption of diets low in carbohydrates and high in protein is associated with an increase in total mortality."

When I read the first publication of the study, back in November, I decided not to write about it since I was focused on penning articles about diabetes throughout National Diabetes Month and this study wasn't about diabetes. It remained on my pile of studies to consider, but as time passed, it seemed less and less important to write about. Now, with it hitting the print edition, and a renewed interest in the findings, it's time to take a look at what the researchers found and how they reached their conclusions.

Jake Young, who writes at Pure Pedantry, thought it worthwhile to take a look too. In summing up the design of the study, he wrote "[j]ust to cross the t's and dot the i's, they also control sex, age, years of schooling, smoking, BMI, physical activity, ethanol intake, and (in the data I am going to talk about) energy intake;" thinking, I believe, that adjusting for these confounding variables leads to higher quality conclusions.

Except in this case, adjusting for some of these variables led to a leap-of-faith extrapolation from the data because without making adjustments there was no significant finding to speak of, "[i]n model 2, the LC/HP score (absolute values) was positively associated with mortality, although the association did not reach statistical significance (P=0.14)." [emphasis mine]

In other words the association was statistically due to chance and therefore a null finding.

But, let's not let that get in the way of a good chance to find statistic significance!

Rather than take the data at face value for absolute intake (what people were eating), the researchers decided to adjust energy intake and considered this adjustment "as they should be, isocaloric..." to show how, after adjusting for energy intake variables things change.

And change they did.

With this one adjustment, statistical significance magically appears and now "mortality was significantly associated with reduction of energy-adjusted carbohydrate intake and nonsignificantly with increasing protein intake."

But still, how exactly to find protein problematic?

Ah, one more adjustment just might do it.

The researchers noted that their "model 3" "does not specify the complementary changes that have to be introduced for the preservation of total energy intake, when carbohydrates and proteins change." So, they created "model 4" and said it was "the most appropriate" since it was both isocaloric (adjusted for energy intake) and now adjusted to reflect changes from less carbohydrate and more protein.

Viola!

"In this model, increasing LC/HP score was significantly associated with mortality (P=0.001)."

Except, no one in the cohort ate like the adjusted diet, the statistically significant findings are not from real people eating real food (absolute intake), but are only found upon adjustment of energy and intake from protein and carbohydrate. The researchers justified this adjustment as necessary with "[i]ndeed, many of contemporary public health policies rely on extrapolations, so that if something is detrimental at a certain exposure level, its effect is likely to be more detrimental at a more extreme level."

Perhaps this is part of the problem with our public health policy? We're basing recommendations on extremes, extrapolated from adjusted models, rather than real world eating habits.

This is how the American Heart Association comes up with recommending less than 7% saturated fat to all Americans, even those at low risk for heart disease; they take data from studies that found no benefit from reducing saturated fat to 10% or less of calories and do the mental gymnastics to leap to an idea that benefit will be seen when saturated fat is less than 7% of calories. No data, just pure extrapolation and wishful thinking.

But, I digress...

There'd be nothing to talk about with this study if the researchers only went with their cohort and their habitual diet. Remember, when the absolute intake data was crunched, there was no statistically significant finding.

It's only after the researchers play with the data and make adjustments - adjustments outside the "norm" of their population cohort - into the extreme models, that they find significance.

In the real world you'll be hard pressed to find someone eating a diet within the extreme models they created. That's because the fundamental flaw in their model adjustment was the belief that decreasing carbohydrate means increasing protein. As the researchers noted in their paper, their adjustment model "relies on opposite changes of two nutrients with equivalent energy values and tends to be unrelated to total energy intake."

Simply put, the assumption was that reduction of carbohydrate translates to an isocaloric increase in protein.

The problem with this is that in the real world, increasing protein beyond what the body needs is extremely difficult due to satiety hormones that effectively shut down hunger when protein intake is adequate and carbohydrate is restricted. So the idea that one is effectively replacing carbohydrate with protein has a limit. A limit that seems beyond the grasp of this research group, who didn't seem to ask the important question - why did those with higher LC/HP (low-carb/high-protein) scores consume less calories than those eating a higher carbohydrate diet?

Rather than delve into this, they adjusted protein as if this group could and would consume more calories and more protein in a linear progression, adjusted their habitual intake to reach an isocaloric level comparable with their higher carboydrate counter-parts. But, because protein is such a sating macronutrient, this adjustment is not based on reality, but is purely hypothetical; and a hypothetical situation that one is likely to find impossible in a real world eating situation.

My take - the researchers would have been better off publishing their findings from the absolute intake data and letting the data stand as it is rather than make various adjustments to convoluted extremes and try to make headlines. Nice try though.