Friday, August 23, 2013

Fat eggs, rabbit starvation and the mercury myth



In my last post, 'Eat More Fat!' I described my preferred sources of fat and how most people really don't require that many carbohydrate to be healthy. 

In this post I'm going to delve into macronutrient breakdowns, why you don't need to go crazy on red meat or protein and why you shouldn't be scared of mercury toxicity in fish. 


Macronutrient breakdowns
One important thing to note is that fat has 9 calories per gram - significantly more than protein and carbohydrate, which both have 4 calories per gram. (Alcohol has 7 calories per gram). 

I typically consume 50-70% of calories from fat, 20-30% from protein and 10-20% from carbohydrates. This seems like a lot of fat but because of the caloric density of fat it is fairly easy to consume such a high percentage of calories as fat.

For example, you may look at eggs as a protein source, but they actually contain roughly equal amounts by weight of fat and protein (three boiled eggs contains about 18gm protein, 16gm fat and 2gm carbs for a total of 224 calories). However, of this 224 calories, 144 is from fat, 72 from protein and 8 from carbs. 

Thus the macronutrient breakdown of whole eggs is roughly 65% fat, 30% protein and 5% carbs… And here you were thinking that those 3 boiled eggs were mostly protein, but they are actually more so a fat source. 

The same goes for most healthy animal products such as oily fish, chicken, beef, lamb, pork, etc, especially given that you don't just eat the leanest cuts. 

This is NOT A BAD THING. This is how it works in nature. Protein is almost always wrapped up with significant amounts of fat. 

It is not natural, or particularly healthy, to eat pure or even very lean protein sources. The human body can only process so much protein before running into some serious issues - usually about 35-45% of calories (Wolf, 2010). 

Beware of the rabbit...
There is a rare phenomenon known as 'rabbit starvation' or 'protein poisoning' whereby if you consume too much protein without adequate fat for a period of time it can lead to acute malnutrition and toxicity in the body that can potentially kill you. 

Of course this is not really an issue as it would be almost impossible to reach such high levels of lean protein consumption (unless you eat only rabbit jerky for days on end or something ridiculous!) 

However, it does point to the fact that you shouldn't be scared of eating the fat with your meat - especially if you have very high quality animal products such as grass-fed, hormone and antibiotic-free, pasture-raised beef. 

Unfortunately the sad nature of industrialised meat production these days means that most of the meat readily and cheaply available at supermarkets barely resembles that of wild meats that we evolved to eat. 

When it comes to conventional, grain/hormone/antibiotic-fed, stressed animals raised in terrible feed-lot conditions, you are probably better off not eating them often (or at all). 

While I occasionally get into debates with vegans over the Paleo diet, I respect the fact that most conventional meat and dairy these days is not particularly healthy, and some of it is downright bad for you. 

However, I will continue to beat the 'quality' drum in saying, sure, avoid conventional meat and dairy if you have ethical or health concerns about it, but don't discount the health benefits of high-quality animal products from good sources. 

In an ideal world I would eat only happy cows and chickens that roamed open pastures and slept peacefully under the stars. Yet while it is possible to track such sources down, it is difficult and often costly. 

I do the best with whatever resources are available... and if I have to settle for wild caught sardines as a staple for a period of time rather than (land) animal protein then so be it.

Maybe one day i'll be able to raise my own cows, chickens, avocados and coconuts... Although I might have to have to separate the coconut farm from the animal pens to protect the chickens from premature death from above. 

Mercury myth?
As an aside, this whole 'mercury' poisoning hoo-haa seems to be greatly overstated. While it is true that larger predatory fish (shark, swordfish, some tuna) do contain potentially harmful levels of mercury, such seafoods also often contains substantial amounts of selenium which binds to the mercury and makes it relatively benign to the body (Ralston, 2012). 

This is the common trap of reductionist thinking whereby we like to focus on one specific factor and decide based on that factor alone whether food x or y is good or bad for us. As always in nature things need to be understood holistically and in context. 

For example, brown rice has more fibre, protein and 'nutrients' than white rice, therefore reductionist thinking would lead us to believe that it must be healthier than white rice. 

But this misses the fact that brown rice also has more anti-nutrients and toxins in the protective hull (rice doesn't want to be eaten either you know!) that make it potentially more harmful than white rice. 

Nutrition is about considering the whole picture and weighing up the costs and benefits of each choice. No food choice will ever be perfect so we have to do the best with what we have and what we know.

But back to mercury, there are exceptions to this rule - for example shark, swordfish and a couple of varieties of large tuna have high mercury to selenium ratios and therefore should be largely avoided, especially by pregnant women. 

But feel free to eat salmon, most types of (smaller) tuna and all other small fish to your heart's content without freaking about mercury. Those mercury fillings in your mouth, if you have any, are far more of a concern!

On farmed fish...
I avoid farmed fish for similar reasons to avoiding conventional meat - unhealthy, overcrowded, unsanitary conditions for animals being fed a diet not suited to them. (Pretty sure wild salmon don't eat corn and soy or need to artificially dye their flesh to look pink!) 

If you are going to eat conventional meat, the leaner cuts seem to be preferable as the fat contains more of the bad stuff (toxins and bio-active hormones) than the protein. If cost is an issue, choose quality over quantity. Better to eat grass-fed once a week than grain-fed twice!

You don't have to eat red meat everyday to be Paleo!
You really don't need to eat huge amounts of meat to be Paleo. You don't even need to eat high-protein to be Paleo. 

People often misconceive the Paleo diet as some kind of extreme caveman diet for men who eat piles of blood-drippingly raw red meat. This is ridiculous! Don't eat red meat at all if you don't want to. You can still be Paleo and healthy without it. 

There is no one Paleo diet. Hell, you can even be a Paleo vegetarian if you want. I wouldn't necessarily recommend it but it is possible… Paleo pescetarian for sure!

On the whole protein debate...
I'm sure some vegans eat more protein than I do, although I would argue that protein from quality animal sources is superior to protein from plant sources for us humans. 

Yes bulls can get jacked eating a ton of grass but we are NOT herbivores with multiple stomachs and prolific gut flora capable of extracting so much nutrition out of grass. Nor are we meant to be very inactive and sit around grazing all day long. Just look what happens when we do! Cow-size humans!

I would rather eat a palm-sized piece of fish or steak for my 30gm of protein rather than a whole cup of almonds or 1kg of broccoli. It just makes sense to me.

I mean how long would it take to gather a whole cup of almonds? (Not to mention all that omega-6 fat and lectins). And is it even healthy/possible to eat 1kg of broccoli and not put your gut/roommate through hell? 

No thanks, you can keep your hemp protein and sunflower seed butter. 

As I said I only eat red meat once or twice a week, if that, and probably eat three times as much fish as I do meat. I also eat less chicken these days as "organic", pasture-raised chicken is very expensive and inaccessible and the fat in chicken is very high in omega-6s. I do eat a lot of high quality eggs though - usually two or more a day.

To finish the commentary on protein, most Westerners are already getting enough in their (crappy) diets so when you go primal/Paleo it is not necessarily about eating MORE protein but rather about improving the QUALITY of your protein - while replacing the bad carbs with good fats. 

For more information on what I eat on a daily basis and some photos and recipes check out the PLAT section of my blog. 

Eat Paleo. Train. Live life! - twitter.com/thepaleomodel

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References

Dr. Nicholas Ralston (2012): 'The Truth about Toxic Mercury in Fish' on Chris Kresser's Revolution Health Radio Podcast, 17 October 2012, http://chriskresser.com/the-truth-about-toxic-mercury-in-fish

Robb Wolf (2010), The Paleo Solution: The Original Human Diet 

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