The winner of our cute li’l NIT pool (god, please spare us from that ever again) ended up being someone anonymous… well, actually, *I* know who it is, but I’m not sure he can out himself. So until we get that little bit of no-fun behind us, I’m going to hand over the reins today to “once a heel” from the comments section, given his expertise on last week’s human body topics.
Given all the crap we’re fed (as it were) about supplements, diets, and what to put in our esophagii, I wanted someone to break it down for us Young MC-style, so here he is:
Ian asked that I write a blog about nutrition, but I don’t feel comfortable giving advice about individual eating/exercise regimens (talk to your doctors). However, I do know a little something about metabolism and biochemistry and, like many of you, share an interest in why things are the way they are. I also prefer to remain an “internet expert” which means I value my anonymity and as such there’s no reason for any of you to ascribe credibility to anything I say here.
So instead I’m going to recommend you watch this:
It’s a 90-minute seminar given by Dr. Robert Lustig to students at UCSF arguing a major factor contributing to the obesity epidemic in this country (and spreading worldwide). Now I know what you’re thinking… but give it a chance. The guy is fairly entertaining. There’s some technical biochemistry stuff in the middle (which he actually undersells, IMO) but any good Carolina grad should be able to follow the rest of it.
Disclaimer: the guy is trying to drive home a point, which means he uses inflammatory language, only pays lip service to other contributing factors, and in some cases, ignores some data that doesn’t quite fit the hypothesis. So while what he says here shouldn’t be taken as the be-all and end-all about why we’re so damn fat, he does highlight some interesting issues in the course of telling his story.
In a nutshell:
1) a key change in our diet began in the 70’s.
We reduced the amount of fat we ate while dramatically increasing the amount of fructose consumption (by as much as 5X).
2) the change was driven by political, economic, and scientific forces that were (at least partially) well-intentioned.
Nixon, who was fighting a “War on Poverty”, didn’t want the cost of food to be a political issue in the elections – food prices needed to get lower (and more stable). Around this time, high fructose corn syrup (HFCS) hit the US – it was so cheap (and sweet) it quickly made its way into everything, including baby formula. Finally, in the early 80’s, health professionals all said we needed to reduce the amount of fat consumed in our diets from 40% to 30% to reduce heart disease.
3) these changes had disastrous consequences.
We did it! Only 30% of our calories now come from fat, but obesity and associated metabolic syndromes (including cardiovascular disease (CVD), Type 2 diabetes, lipidemias, hypertension, etc) have simultaneously gone through the roof. It can’t all be blamed on lifestyle choices.
4) a little bit of knowledge can be a dangerous thing – to solve one problem we inadvertently made it worse in ways couldn’t predict at the time because the body is a complicated thing and we still don’t know much about how it works.
Because taking the fat out of food makes it taste like crap, we had to add HFCS as a sweetener to make it palatable. Turns out, however, there were some interpretation flaws with the fat=CVD studies, in part because we didn’t know that there was “good fat” and “bad fat”.
We also didn’t understand that fructose is not metabolized in the same way as glucose (another prominent sugar in our diet). Only a relatively small amount of glucose gets converted to fat. Much of the excess glucose is stored as glycogen in the liver – you might gain weight this way, but you can basically store an unlimited amount of glycogen without getting sick.
In contrast, almost all the fructose gets converted to “bad fat”. In other words, all the fat we took out of our diets was more than offset by the fat derived from the fructose we added in its place, and we added a lot! Worse yet, when you eat glucose you induce hormonal changes that ultimately signal to your brain that you don’t need to eat anymore. The way in which fructose is metabolized may partially interfere with those signals so you don’t feel as full and you keep eating more than you should.
5) “when God made the poison, he packaged it with the antidote.”
But isn’t fructose normally found in fruit and aren’t fruits good for us? Yes, but the amount we ingest from fruits is way less than what we’re putting in everything else. Fruits have a lot of fiber as well. Amongst other things, fiber limits the amount we eat and the efficiency with which it’s absorbed. Unfortunately, we’ve also taken all the fiber out of our foods in order to increase shelf life, allow for freezing, and facilitate preparation.
6) even though we can see this was a mistake, the myths persist with many folks thinking they’re eating healthy (less fat) when they’re not. Furthermore, there’s a whole set of beholden institutions that oppose correcting the problem.
If this stuff is so bad for us, why don’t the FDA, USDA, etc. do something about it? Food is one of the few things we still export to the rest of the world (along with weapons and entertainment). Who’s going admit that we intentionally make our food less safe? Besides, if you took out the HFCS and put back the fiber the food would taste worse, cost more, and couldn’t be frozen/stored for shipping. You don’t need to be an econ major to do the math.
7) it basically comes down to a choice between being fat or flatulent.
No one is advocating completely cutting fructose from your diet but if you want to start eating healthier, try to reduce the amount of foods you eat with added fructose (in all its various forms) and eat more fiber. You’ll eat less (and feel less hungry), you won’t get as fat, and you’ll greatly reduce your risk for metabolic syndrome diseases.
But, you will fart more.