Tuesday, August 28, 2012

Protein Is Essential, But Too Much is Too Much

Why do I consider protein the important focus for the short and long-term?

In a word, it's satiety.

That and animal based protein is nutrient-dense; when in included at adequate levels in your diet, it is much easier to meet nutrient needs each day.

Most calorie restricted diets not only reduce calories, they significantly reduce protein intake. I think this is the cause of the hunger often reported once an individual is into their lower calorie diet after a few weeks. While starvation does work in the short term, long-term 95% of people who lose weight will gain it back within three years, 99% will within five.

When you do not eat enough protein, you are starving, slowly but surely; and that holds true even in a state of excess calorie consumption.

Protein is a really neat macronutrient, not only does it provide us with essential amino acids, it also is used throughout the body to repair and build muscle, cells and tissue. Amino acids are critical to maintain our health, but they're not really a great energy source - when the body's energy sources are low, it begins to degrade proteins for use as an alternative energy source. Amino acids can be classified as glucogenic or ketogenic.

Glucogenic amino acids can be degraded to pyruvate or an intermediate in the Krebs Cycle. They are named glucogenic because they can produce glucose under conditions of low glucose. This process is also known as gluconeogenesis, or the production of "new glucose." Amino acids form glucose through degradation to pyruvate or an intermediate in the Krebs Cycle. The intermediates can then be converted to oxaloacetate, the main precursor for gluconeogenesis. (glucogenic amino acids: alanine, cysteine, glycine, serine, threonine, tryptophan, asparagine, aspartate, phenylalanine, tyrosine, isoleucine, methionine, threonine, valine, arginine, glutamate, glutamine, histidine, and proline).

In contrast, ketogenic amino acids can produce ketones when energy sources are low. Some of these amino acids are degraded directly to ketone bodies such as acetoacetate (leucine, lysine, phenylalanine, tryptophan, and tyrosine). The other ketogenic amino acids can be converted to acetyl CoA. Acetyl CoA has several different fates, one of which is the conversion to acetoacetate. Although not a preferential energy source, acetoacetate can be metabolized by the brain and muscle for energy when blood glucose is low and acetoacetate cannot be used in gluconeogenesis, since acetyl CoA cannot be converted directly to oxaloacetate.

The above is what happens when you consume adequate protein each day. So, what happens if you consume too many calories and/or too much protein? Basically, when energy sources are high, both glucogenic and ketogenic amino acids are converted to fatty acids through the intermediate acetyl CoA. Other amino acids that are degraded to intermediates in the Krebs Cycle are siphoned off into the production of urea, a nitrogenous carboxyl compound that is filtered through the kidneys and secreted in the urine.

Put another way, you now have fatty acids that can store as body fat.

It is for this reason one should not consider a low-carb diet as an all-you-can-eat buffet, just hold the carbs. Whether you're new to carbohydrate restriction, or a long-term veteren, you need to know how much protein you need at minimum, and also understand where the maximum is for weight loss and weight maintenance.

How does one know how much is enough and how much is too much?

It depends largely on weight. In fact, it is really all about how much one weighs. Protein requirements are based on body weight because body weight takes into account mass, lean body tissue and structural maintenance. The more you weigh, the more protein you need; the less you weigh, the less you need.

The absolute minimum, to meet EAA requirements is considered 0.8g/kg body weight. On a low-carb or carb-controlled diet, one does require more to fuel gluconeogenesis and most agree that protein requirement ranges, from 1.0g/kg to 1.5g/kg. A good middle maximum is 1.2g/kg if someone is active. For this reason, I usually provide individuals with a minimum target for protein each day based on the EAA minimum (0.8g/kg) from animal foods, then provide a range of maximum from all sources, including the vegetables they'll consume, that ranges 1.0g/kg and 1.2g/kg. In the years I've helped people understand how much protein is enough, I've only encountered a couple who were very active and could consume 1.5g/kg.

The chart below provides protein requirement and upper protein range for those restricting carbohydrate in their diet.


Saturday, August 25, 2012

Do Calories Count?

We often hear, and even I've said, do not count calories on a low-carb diet. The advice, on its face, is sound because when someone starts a low-carb diet, overweight or obese, counting only grams of carbohydrate, they reduce their calorie intake even when eating ad libidum; so having to count calories over-complicates a dietary approach that already lowers calorie intake anyway.

But saying "don't count calories" does not mean that calories do not matter. I wrote about how it is a myth that calories don't count back in 2005 (here).

They do, they always have and always will - but they're not always perfectly matched to calories-in/calories-out (CICO) since nutrient-density of the food you eat also matters, along with the fact that the body compensates daily with homeostsis and how much we move, so it's not always burning exactly the same calories each day. But over a long-term average, calculated active metabolic rate (AMR) is a fairly accurate target for calories needed on average each day to maintain weight when you're meeting requirements for essential nutrients.

So, should you count calories?

Based on years of experience, my suggestion remains - when you start a low-carb diet, do not count calories.

If you stall, look at calories - you may be eating too many, or (gasp) not enough.

If you gain, look at calories - I can promise you that if you're keeping your carbohydrate restricted, gaining almost always means you're eating surplus calories from fat and protein in excess of your active metabolic rate (AMR); small fluctuations are normal, but gain on gain on gain while restricting carbohydrate is excess calories.

It is a MYTH that you cannot gain weight if you just keep your carbohydrate restricted, the fact is calories do matter. In addition,hormones, glycogen stores, and metabolic rate matter too, but if you're gaining weight while keeping carbohydrate restricted, you're not gaining in a calorie deficit, you're gaining in a calorie surplus.

Tuesday, August 14, 2012

Where Are We Today?

When I started this blog back in 2005, in my second post, Hunter-Gatherers, I looked at a review by Loren Cordain et al, about the maronutrient estimations in worldwide hunter-gather diets.

I noted,

Their findings included

  • Most (73%) of the worldwide hunter-gatherer societies derived >50% (56–65% of energy) of their subsistence from animal foods, whereas only 14% of these societies derived >50% (56–65% of energy) of their subsistence from gathered plant foods.

  • This high reliance on animal-based foods coupled with the relatively low carbohydrate content of wild plant foods produces universally characteristic macronutrient consumption ratios in which protein is elevated (19–35% of energy) at the expense of carbohydrates (22–40% of energy).

So, most of the hunter-gathers are eating 56-65% of their energy from animal foods, providing 19-35% of their calories as protein and just 22-40% of their calories from carbohydrate.

In a "real world" 2000-calorie a day diet, what does such a macronutrient mix look like?

19-35% of calories from protein = 380 to 700 calories or 95g to 175g of protein, with most coming from animal foods

22-40% of calories from carbohydrate = 440 to 800 calories or 110g to 200g of carbohydrate

The remaining calories, from fat = 500 to 1180 calories, or 25-59% or 55g to 131g of fat

And continued by stating that "[t]hese ratios are very much in line with controlled-carbohydrate nutrition ratios, which generally holds that carbohydrate is limited to 40% or less for daily calorie intake. The mix of fat and protein calories in a controlled-carb approach is highly individualized and the goal is to include quality protein in adequate amounts and only include quality fats and oils."

Six years later, I still hold the opinion that today, controlled-carb nutrition can model the diet of our ancestors; typically called Paleo and/or Primal eating. In fact, I'd say it would be difficult to consume a diet high in carbohydrate (greater than 40% of calories from carbohydrate) without specifically focusing on eating a high level of carbohydrate each day.

Has this become clearer in the years since I started this blog?

Not really.

In truth, time has created a variety of differing opinions that leave many confused; worse is that some seek to create divisions where none need be.

Recently Jimmy Moore posted AHS12: A Dichotomy Of Differing Interpretations Of What Paleo Is. In it, he writes, "However, when it comes to starchy carbohydrate sources of nutrition such as white potatoes, sweet potatoes or white rice (the toxin-free “safe starches” identified as such by Paul Jaminet), there’s a definite divide between those who avoid them because they raise blood sugar and insulin levels as well as lipid numbers to unhealthy levels (...) and those who believe these starches provide the adequate glucose your body needs to perform and function as it was intended to. That’s quite a division within the Paleo community that doesn’t have an easy answer to bridge the chasm."

Is this really a division within the Paleo community? Is this really a chasm that needs a bridge?

Honestly, I don't think so.

As I noted in my comments on his link to the blog on Facebook, "Paleo is a guideline to the types of foods one can eat, not the amount one *should* eat of any particular macronutrient; low-carb is one dietary approach which fits in with a paleo diet. Both focus on quality protein, good fats and nutrient dense carbohydrate. What level of carbohydrate you consume is your business, Paleo is basically just the framework for what foods to choose from. I don't think paleo has to be low-carb to be effective. It really is dependent on the individual."

One of the things I've learned over the last decade is that nothing is set in stone when it comes to macronutrients - the diets of healthy, normal weight individuals, around the globe vary greatly, what matters most is the micronutrient composition in the overall diet; it's habitually meeting or exceeding essential fatty acids (EFA), essential amino acids (EAA), essential vitamins, minerals and trace elements. The Japanese do that by consuming copious amounts of fish and pork, but their overall diet is lower in fat than those in France, who also do that with a wide variety of meat, full-fat dairy and a boatload of non-starchy vegetables and fruits. Both diets also have starchier foods too, yet these populations are not, nor have they ever been, suffering alarming rates of obesity.


If you look at diet quality, both Japan and France are eating serious quality foods, real foods, compared to the US and other nations with exploding obesity rates.

Quality matters; it is the heart-and-soul of Paleo, it is the heart-and-soul of Primal. The focus of ancestral eating (Paleo and Primal) is real food, shunning the processed and choosing quality. It defines no specific level of macronutrients by gram or percentage, but does point to nutrient density and meeting essential nutrient requirements. While one can follow a low-carb diet and eat Paleo-Primal style, that does not mean Paleo-Primal is low-carb per se; although, as noted i the paper by Cordain et al, Paleo-Primal diets are lower in carbohydrate than the Standard American Diet (SAD).

I do not think we have this deep divide, I think what we're seeing is a wide variety of approaches to reach the same goal - eating healthfully for the long-term. For some that includes soaked and fermented grains (Weston A. Price Foundation), for others eliminating grains is important, but dairy and legumes, along with other foods that are newer in our history may be included (Primal), and still there are those who hold that those foods, eaten by others in the spectrum of eating "real food", are simply unacceptable, just say no (Paleo). At the end of the day, the common theme amongst all - eat real food!

As one commenter noted on Jimmy's blog, "We do not currently understand everything about the variation in individual response to carbohydrates, such as sex differences, or dependence on history of metabolic dysfunction. We also do not completely understand how an individual’s dietary needs may change as a function of time depending on external
conditions. In addition, how much carbohydrate a person will do best on will depend on their goals (performance, longevity, reproductive health), but once again we do not understand the complete picture!"

I concur! Many things factor into weight loss and long-term health, eating real food is the one thing that continues to be the most important aspect of a healthy diet.

Chris Kresser nailed it last year, in his post Beyond Paleo: Moving from a Paleo Diet to a Paleo Template.