Glycemic Index Woes

The glycemic index has been a popular tool for years.  Yet a fair amount of research has revealed significant holes in it’s utility.  Can the GI be trusted to aid in actually controlling your blood sugar?  I won’t cover how this effects body composition because you know my stance on this subject. (TL;DR carbs are no more fattening than fats or protein)

I shall cover 2 main issues with the GI.

  1. How do foods with varying GI’s affect the glycemic response?
  2. How accurate is the GI?

 

GI and Glucose Stuff

I came over a new study that examined the glycemic response to fast and slow digesting carbohydrates.  A fast digesting carbohydrate, according to the GI will result in a large glycemic response.  A slow digesting carbohydrate, according to the GI, results in a slower glycemic response.  This is what the GI says.  What does good ole science say?

The researchers sought out to find out if fast and slow digesting carbohydrates actually resulted in a different glycemic response.  They tested 10 healthy dudes.  So one could bitch incessantly how this doesn’t apply to:

  1. Children
  2. Middle-aged
  3. Elderly
  4. Obese
  5. Females
  6. The list goes on and on.
  So if you’re on that list, you better close this window because it doesn’t apply to you! (I keed, I keed)

The study used enriched wheat bread or pasta.  The researchers looked how these foods affected ‘rate of appearance of exogenous glucose (RaE), endogenous glucose production, and glucose clearance rate (GCR). In addition, postprandial plasma concentrations of glucose, insulin, glucagon, and glucose-dependent insulinotropic polypeptide (GIP) were analyzed.’

According to the GI the results would be probably be something like this: Pasta has a higher GI than Wheat bread according to the study, as the rate in which glucose was present in the blood was faster in bread.  Since the pasta has a higher GI, you would expect a larger spike in glucose as it enters the bloodstream.

There were obviously other factors at work though, as this isn’t what happened.  The two foods actually had similar glycemic responses.  How can this be?

Since the low glycemic foods elicited a lower insulin response the GCR glucose clearing rate  (from the blood stream) was slower than the rapid digesting carbohydrate.  The fast digesting carbohydrate had a faster GCR because it had a higher insulin response.

Even though a given carbohydrate can cause varying GIP and insulin secretions a similar glycemic response can occur.

 

GI Accuracy

Whatever ‘bro’

The second part of this will be shorter.  In my first blog entry I wrote about how different GI’s will have different values on different indices.  I mentioned that I found the GI of carrots on two different indices.  One had them valued at 47 and the other at 90.  That’s a very large difference.

Another study looked at this very subject.  They found that whole meal GI values were 22-50% overestimated over the actual value.  GI for individual foods were also overestimated.  So take that for what it’s worth… Which is a lot by the way.

 

The lack of accuracy in the GI has implications on the GL as well.  GL is sometimes looked as a more “polished” version of the GI, as it takes into account the volume of food needed to illicit a blood glucose spike.  For instance, watermelon has a reasonably large GI score of ~70 (give or take 35, heheh) but the GL is only 4(this number would also be skewed).   So watermelon isn’t all that bad, because you’d have eat a disgusting amount of it in order to actually raise your blood glucose.

Yet, if the GI is not accurate then GL will not be accurate as well.  So using these charts is really quite fruitless.

Oh and by the way, GI will be different for people with differing insulin responses.  So peoples’ glucose will be transported out of the blood stream faster than others, even with the same food.  So all in all, the GI is pretty much.. Meh.

What To Do With This

There are two major knocks against the GI. Does this make the GI useless?  I personally don’t use the GI, glycemic load (GL), or insulin index (II).  If you just focus on eating whole foods rather than the usual crap that comes in a box, you will probably have the same results as following a damn index.

The researchers in the first study cited concluded “These types of starchy products cannot be identified by using the glycemic index and therefore another classification system may be necessary.”  Another useless classification system is not needed because it will be another set of particulars that nobody will follow.

I’m not an RD, so I can’t dispense information about helping people control their diabetes.  I can however give my opinion based on what I’ve seen from research.  I have yet to see a low carbohydrate diet that didn’t drastically reduce fasted blood glucose levels.  Yet for some reason, RD’s never suggest these kinds of diets to their clients.  I have no idea why that is.

In terms of fat loss, I’d guide you to this.   You can eat carbohydrates and lose weight.  No question about that.

If you’re trying to gain muscle mass…  You know what to do… Consume carbohydrates, all of them, in the entire world.

Peace

 

 

My First Powerlifting Meet

Perhaps some of my readers have above average strength, and you want to showcase your talents in competition?  Well powerlifting is where you’d probably be best off doing this, unless you lift crazy heavy, odd shaped objects (which would make strongman you sport of choice)  I’ll discuss my first meet, as well as the little things that can provide you with somewhat of an edge if you decide to compete at some point.

I got to the meet way too early because of a registering mess up on my part.  Live an learn.  It’s probably a good idea to still get there a little early, so you can load up on carbs and get your weight up a bit before the action begins.  I didn’t eat too much, but I didn’t want to have an uneasy stomach going into any of my lifts.  Although puking on the spotters and crowd would be highly entertaining for spectators (who would not be affected by said puke) I decided to play it safe and just get a little bit of food in me that I knew would agree.

I had some fruit and some PB&J’s.  Easy, and delicious.  I also had a Powerade and a bottle of water.  Pretty small amount of fluid I’d say. Yet I urinated no less than 30 times during the entire competition.  It was annoying as hell.  I guess my nerves got the best of me in the urination department…

The first lift was the squat.  I opened with 195kg and it was incredibly easy.  This is literally warmup weight for me during my daily squatting sessions.  I chose this lightweight as an opener because I wanted to makes sure that I made my first lift and made it easily.

[youtube]http://www.youtube.com/watch?v=Gw6Aay599nU&list=UU9lXiihQyH_Bg25E2XVR4tw&index=9&feature=plcp[/youtube]

As you can see it was incredibly easy, but being a complete newb to the rules of powerlifting, I completely forgot to wait for the rack command.  Three red lights and no lifts.  I wasn’t phased by this as it was incredibly easy, I just made a silly error that I will never make again.

My second squat attempt at 200kg was also a cinch.It wasn’t a grinder in any way, shape, or form.  [youtube]http://www.youtube.com/watch?v=L4EDThCopho&list=UU9lXiihQyH_Bg25E2XVR4tw&index=8&feature=plcp[/youtube]

My third attempt at 205 was pretty conservative as well.  There was definitely a little bit of grinding on the way up, but I could’ve gone with more.  Oh well, got three whites and moved on to the bench press.[youtube]http://www.youtube.com/watch?v=2g0Cn9LQHRY&list=UU9lXiihQyH_Bg25E2XVR4tw&index=7&feature=plcp[/youtube]

I knew going in that my bench would pretty much be complete crap.  This is the lift that by far needs to be improved the most.  I had hit 335 for a single in training in the summer.  So I thought that I’d be good for 350ish during the meet.  However, my bench training leading up the meet just wasn’t very good and I knew that 350 was probably out reach.

My opener was easy and my second attempt wasn’t very hard either.  Looking back, I probably should’ve attempted 147kg instead of 150, I probably would’ve made that, oh well!  My upper back was cramping like it never has before after my first attempt.  That arch can be killer.  Luckily I only had to bench three damn times.

[youtube] http://www.youtube.com/watch?v=t6cAlzb0FO4&list=UU9lXiihQyH_Bg25E2XVR4tw&index=6&feature=plcp[/youtube]

[youtube]http://www.youtube.com/watch?v=qcO5l5wO2lA&list=UU9lXiihQyH_Bg25E2XVR4tw&index=5&feature=plcp[/youtube]

[youtube]http://www.youtube.com/watch?v=FjfQ17CjoMk&list=UU9lXiihQyH_Bg25E2XVR4tw&index=2&feature=plcp[/youtube]

I was a little concerned for the deadlift, because my back was seriously sore.  My upper back took a pounding from arching for the bench, and my lower back was definitely feeling the effects from squatting.  After resting for an hour and putting some tiger balm on there, I felt much better.  My warm-ups felt fast and light, so I was back to being a happy camper.

I forgot to bring baby powder for my legs and arms.  It makes the bar and your body slippery, so if the bar or your arms touch any part of your body, there is minimal friction to overcome.  Luckily, powerlifters are very generous and I was able to use some from the other gentleman in my weight class.

My first two attempts were very smooth.  My second attempt was a PR.  I was planning on attempting 650lbs for this meet, but decided I’d rather go for 290kg.

[youtube]  http://www.youtube.com/watch?v=WjcbhBD4ATg&list=UU9lXiihQyH_Bg25E2XVR4tw&index=4&feature=plcp[/youtube]

[youtube]http://www.youtube.com/watch?v=NHXv9RNNvIY&list=UU9lXiihQyH_Bg25E2XVR4tw&index=1&feature=plcp[/youtube]

[youtube]http://www.youtube.com/watch?v=pGaBRshS0u4&list=UU9lXiihQyH_Bg25E2XVR4tw&index=3&feature=plcp[/youtube]

As you can see from the video above, I had a slight pause around the lockout of my deadlift.  So when I put the bar back down, I saw one white light, and one red light.  I needed 2 whites for the lift to be considered good.  After a slight pause I got my white light!

Takeaways from the meet:

  • When people say powerlifters are nice, it’s true.  Everyone was very supportive and wanted everyone to succeed.  I didn’t see any huge egos or anything like that.
  • Equipment that you should bring that you maybe wouldn’t think of: baby powder, tiger balm, extra shirt, shorts, long sleeve shirt or hoodie.  Staying warm was important during the whole meet.  You don’t want to be cold right before you max out…
  • If you invite someone, tell them it’s going to take a while.  This is how meets are, they’re long and can at times be boring.  All of the weight classes are put together, so there are pretty long waits between lifts.  At nationals, they split the event into four days, which makes the wait times much shorter.  Excellent.
  • Open with a light weight.  I feel that hitting your opener is vital.  It ensures you don’t bomb out of the meet, and gives you confidence for your next attempt.  If you don’t hit your opener because you fail the lift (not a technical error) then you will probably have to take the same weight again.  This means that you effectively get only two attempts, as one was wasted.
  • Talk to other competitors.  They know all the technical rules and are pretty much all willing to help in anyway.  Since I was new, I had a lot of questions.  They were all answered easily by more experienced lifters.

 

I ended up winning my weight class.  Since I totalled 640kg (1408lbs) I qualified for Canadian Nationals.  They’re being held at the Richmond Oval this year.  I’m super excited to compete on a National level.  Looking at the numbers of some these guys, I don’t know how well I’ll place, but it’ll be another great experience.  I got second place in the best lifter award for the open category.  The best lifter is judged by a Wilks coefficient: “The Wilks Coefficient or Wilks Formula is a coefficient that can be used to measure the strength of a powerlifter against other powerlifters despite the different weights of the lifters.”  I lost by one point!

I had a great time and I am definitely excited to compete in Nationals coming in March.

Peace!