This week Nick has posed a couple of Paleo-related questions that I’ll address today. First up, tater talk:

I have a question about potatoes for you:

Regular potatoes (white, yellow, golden, etc) are a root vegetable (not harvested). Since they are gluten free (although high GI), why are they “banned” from the paleo list? If they aren’t allowed, is there a reason why sweet potatoes are allowed?

This question is slightly misleading based on some assumptions regarding sweet potatoes on Paleo. To clarify:

1. If the goal is fat loss, they are not allowed.
2. They are recommended for other populations only in a post-workout (PWO) window.

Those things noted, sweet potatoes are preferred due to having more nutrients and slightly lower GI/GL than white potatoes. White potatoes are truly “empty calories” and displace more useful and nutritious foods in one’s diet. Sweet potatoes were mentioned in Cordain’s book Paleo Diet for Athletes (which focuses on endurance athletes). As such, their use for PWO meals should be limited to after a hard metcon and not really necessary after a strength training only session. (For example, after Fight Gone Bad is a great time. After Tuesday’s bench and power cleans, not so much.)

While they may be gluten-free, they still will induce a blood sugar spike and can derail insulin sensitivity, which is important to everyone — not just those seeking fat-loss. This is why to keep them in the PWO window.

Robb Wolf also covered this in more detail on his site:

PWO Meal

The idea of a PWO meal containing carbs (and protein) is to take advantage of a period of time in which the muscles are particularly insulin sensitiveve. We can fly nutrients into the muscle “under the radar” via a mechanism called “non insulin mediated glucose transport”. Amino acids are also taken in during this time and may play a synergistic role in both glycogen repletion but also decreasing inflammation that accompanies hard training. Said another way, you recover from exertion faster. So, what should ya eat? We actually want a starchy carb as our primary carb. Yams and sweet potatoes are great options as they are also highly nutritious. Fruit should be used sparingly in this meal if one is focused on optimized glycogen repletion as fructose refills liver glycogen first, and once liver glycogen is full we up-regulate the lipogenic activity of the liver and start down the road towards fat gain and insulin resistance.

Read more here, especially the comments and his answers: http://robbwolf.com/2008/11/03/post-wo-nutrition/

Hey Marcus, just got into an argument with a co-worker about bacon.

Since it is a source of both protein and fats (have to watch out for salt levels…), is it still healthy with its high levels of saturated fat? Again, this goes back to my question in the gym not too long ago about saturated fats: are they good for us?

First off, learn to stop getting in arguments with coworkers. You’re bound to run into plenty of people who bow before the misguided food pyramid and it’s doubtful you’ll change their mind. Vegans are one of the groups who most like to use the phrase “artery-clogging saturated fat”. As has been mentioned before, we largely have Ancel Keys to thank for this mindset. However, studies have shown that saturated fat is not the demon it was made to be. (Not that groups still haven’t tried to link it to cancer and various other diseases.) Indeed, I posted before on a study showing how individuals consuming more saturated fat had better lipids and lost more weight. Recently, Robb Wolf also posted on his Facebook page this news article which spoke about recent research with regard to saturated fat and it’s presumed link to CVD:

“Although diets inordinately high in fat and saturated fat are associated with increased cardiovascular disease risk in some individuals, assuming that saturated fat at any intake level is harmful is an over-simplification and not supported by scientific evidence.”

Okay, so the key question is — what are those “some individuals” that are at higher risk? It would be those consuming high amounts of carbohydrates, particularly refined grains/sugars/etc. The reason why is that saturated fat reacts with the elevated insulin levels to cause a shift in one’s LDL to small, dense particles. These are the kind that can wreak havoc in your arteries. Of course, if one is consuming ancestral levels of carbohydrates from fruits and vegetables as recommended on the Paleo diet, this isn’t an issue. Just don’t try to have a BLT on white bread… that’s just suicidal.

As far as whether saturated fat is good for us, I will link to this article from Dr. Mary Enig that Sean posted in his Ancel Keys article. Aside from containing a lot of solid information, it breaks down a list of benefits of the supposed bogeymen of the nutritional world — saturated fat and cholesterol.

Thanks Nick for playing along and submitting questions!

WOD 10.07.10

Make Up Day