For the sake of record keeping, it's Wednesday September 21st.
Just a week since the last Fit4Boulders update? What is this lunacy!? Well, it occurred to me after I decided to try out a dietary change today that I've said a lot about how I'm working out to get in shape for climbing, but nothing about my diet. So, I figured I'd make a super-informative post about nutrition.
But first, some stuff about how I'm working out to get in shape for climbing. I believe I've identified two deficiencies in my body's fitness levels: my abs and my upper back. Also known as the parts of the body most commonly associated with climbing. Since it looks like it will still be a while before I actually step into the climbing gym, because of reasons, I'm going to be spending a lot of time on those two muscle groups, and less on my chest. And it's always leg day. I recently remembered that I have an ab wheel, which I've gotten some good use out of this week. My abs are sore. This is a good thing.
Anyway, after watching some related YouTube videos, I ended up reading a lot of articles last night about how bread is the devil when it comes to weight management. This isn't quite true, for reasons too numerous to enumerate here, but it is true that different types of bread can be better or worse for you. It largely has to do with how your body uses insulin.
I happen to own a human physiology textbook, and I spent about an hour reading up about insulin and digestion tonight. To grossly oversimplify things, when you eat, the carbs and protein are digested into glucose (sugar) and absorbed into your blood stream. In response to this elevated amount of glucose, your pancreas produces more insulin, which moves glucose from your blood into your other tissues. Once enough glucose has been removed, insulin production stops. (Sidenote: fat actually inhibits glucose absorption, so anyone who says you should avoid fatty foods just because they contain fat is wrong. In fact, a healthy diet gets 20% of its calories from protein, 20% from carbs, and 60% from fat.)
So that's how insulin works, at a very basic level. Insulin production scales based on how quickly glucose is being absorbed into the blood. So if you eat a lot of candy, which has simple sugars that are absorbed quickly, your insulin spikes in order to get rid of it. Different food is metabolized at different speeds, and the individual nutrients are also metabolized at different speeds. i.e. sugar metabolizes faster than starch, even though they may come from the same food item.
Now look at the nutrition information on a slice of white bread. Conveniently, if you google bread nutrition it puts it right there on the page for you. Per 100g of white bread, 5g is processed sugar. That's 5%. That's because white bread (and many wheat breads) actually contain added sugar as part of the baking process. The cracked wheat bread in my fridge (which is almost gone) has 2g per 75g portion. Now the obvious question is: is this a problem?
The straightforward answer is maybe. It has to do with how the body processes carbs, which includes sugar. Most carbs are combinations of various sugar chains. The simpler the chain, the faster your body breaks it down and absorbs it into the bloodstream. If you've ever heard about "simple" and "complex" carbohydrates, this is what that means. If you eat lots of simple carbs, your insulin levels are going to spike throughout the day. If you eat lots of complex carbs instead, they take longer to break down, so your insulin levels will rise more gradually, to a lower amount overall.
However, that doesn't tell the whole story. Because you don't just eat carbs, you eat food. And food contains lots of stuff. For this reason, researchers developed the Glycemic Index (GI). The higher a food's GI rating, the more it spikes your insulin levels. Since spiking your insulin levels can contribute to things like heart disease, type 2 diabetes, and weight gain, food with a lower GI is generally preferable. This also takes into account that people tend to eat foods in combination: white bread alone has a high GI, but when you add meat and cheese to it, the protein and fat affect digestion rates, and the GI actually lowers. Toast with butter has a lower GI than toast alone.
But again, that doesn't tell the whole story. Because it's not just about the GI, but how much of the related carbs you're eating per portion size. One piece of candy isn't too bad, but if you try to eat, say, an entire 5lb gummi bear, and you make your body try to digest it, you will actually die. Seriously, it's a really good thing Michael threw that all up. For this reason, researchers developed the Glycemic Load rating (GL), wherein you multiply the GI by the number of carbs per serving, and then divide by 100. And again, the lower the number, the better for you.
A general rule of thumb you can follow is to check what percentage of a food's calories come from sugar, and whether sugar is listed as an ingredient. Since refined sugar is pre-processed, the higher the percentage of sugar in a food, the faster it will likely be absorbed. This obviously isn't 100% accurate, as apples have lots of sugar but a very low GL, and ketchup contains "liquid sugar" and 80% of its calories come from sugar and it still has a low GI anyway, but if you're looking for something quick to apply in the supermarket, it's passable.
Which brings us back to added sugar in bread. Lots of breads include processed sugar for flavour. It's easy enough to spot: just look at the list of ingredients. If the word sugar appears, then there's added sugar. Also, some breads have a litany of chemicals as ingredients as well, whose purpose and effects on digestion you'll never know. Now, if you only have a couple slices of bread a day, this probably isn't a big deal. However, I tend to eat as many as 6-8 slices a day in various combinations of toast and sandwich. That's a lot of bread.
So I decided to switch it up today. Instead of buying my usual loafs of bread, being Old Mill Whole Wheat and Country Harvest Ancient Grains - both of which have added sugar - I picked up a Dimpflmeier Pumpernickel, and a Rudolph's Bavarian Multi Grain. They're more expensive, but bearably so, and each of them have 0g of sugar per serving. This is an experiment: next time I buy bread, I'll probably get a different type, like a light rye. My goal is to expand my bread horizons, which feels just as pompous typing it as I'm sure it sounds reading it.
Now, the obvious question is: after I've made such a big deal about how weight management is a simple calories in vs calories out issue, why do I care about the type of bread I'm eating? Two reasons. First, I have heart attacks on both sides of my family. For most of the last 10 years, I've worked out purely preventatively, to keep my heart in shape. If eating healthier bread can help reduce the chance of heart issues down the line, I'm willing to give it a shot.
Second, as I said in the previous paragraph, this is an experiment. I'm changing up the bread I'm eating, and I'm going to see what happens. I've lost about 4lbs so far with a small amount of tweaks to my diet, and this is another tweak. I'm going to track my progress, as I've been doing for the last 3 months, and if it turns out I have more energy, or I lose weight more quickly, I'm going to call that a win. And if neither of those things happen, then I still get to eat more different types of bread. There really isn't a way for me to lose in this endeavour.
Now, I don't expect you to just take my word for it with this journal. I expect you to want to verify the things I've said. You can google insulin to learn about the role it plays. Most of the information in this journal originated with this Harvard School Of Public Health article on carbohydrates and blood sugar. And if you want to see a table of various foods and their GI and GL values, check out this Harvard Medical School article. Some surprises therein: Coca Cola is better for you than Ocean Spray Cranberry Cocktail, raisins are terrible, and the length of time you cook pasta for affects its GI and GL values. This page on mendosa.com claims to be the definitive resource for GI and GL information.
But enough physiology and science, here's Alex Megos doing something awesome: