Review & Critique: The Skinny on Obesity ~ Part II Sickeningly Inaccurate

Previously:  Intro & Part I

The second installment of the University of California production, The Skinny on Obesity, featuring Dr. Robert Lustig and colleagues is entitled Sickeningly Sweet.  I've embedded the video at right.  I've entitled this installment of my Review & Critique Sickeningly Inaccurate.  That is, frankly an understatement about the information presented in this episode.  This video epitomizes what's wrong with many of the "anti-establishment" nutritional experts.  You do not counter bad science with more bad science.  This is what Lustig does here.  And it's not controversial -- at least there's some evidence supporting the lipid hypothesis -- but the "science" here is counter to known basic biochemistry and in opposition to the vast majority of the evidence of metabolism such as de novo lipogenesis.

NOTES

• Juxtaposes these stats:  1985: 2655 cal      2010: 2866 cal    8% increase with % diabetes = 0.62 in 1985, increased to 5.13 in 2010,  727% increase to somehow show that diabetes doesn't rise in correlation to intake.
• Sugar is 50X more potent in explaining diabetes rates than calories
• 1700's became gourmets fat and carb on the same plate
• 20th century in same food gourmands (shows pizza)
• "Sugar because of its unique composition is the only food on the planet that is both fat and carbohydrate at the same time"
• "Even fatty fruits, coconut, olive, avocado have no carb.  There is no foodstuff on this planet that has both fat and carbohydrate at the same time.  It's one or the other, because that's evolution, that's nature, that's what God did."
• Glucose uninteresting not very sweet, Fructose very sweet we crave it
• Glucose metabolized by all tissues, only 20% to liver
• Fructose only metabolized in liver - overloading liver
• Fructose goes straight to mitochondria goes to fat.  Mitochondrial meltdown, mitochondrial constipation, mitochondrial disease.
• Fructose is a dose dependent hepatotoxin just like alcohol.  Fructose is more like alcohol than anything else.  Liver fat, IR, extra insulin, driving weight gain, driving HBP, driving heart disease, driving cell division/cancer, wearing out your pancreas which drives diabetes.
• If you're starving or glycogen depleted from a marathon, then fructose is OK to consume
• But if you're not running marathons, it's just turned into liver fat
• Sugar kills processed food and it's killing us
• E:  more than 5 ingredients it's probably a processed food and it's almost impossible to not get added sugars that are toxic.
• Brownell's Food Fight -- Food available, in places not normal, designed to taste very good to keep eating.  These are important, but ...
• We're talking about real toxins, poisons, damage mitochondria make you sick.  That's what I'm talking about. 
• Only one thing that matters and that's sugar.

Teasing out Myths / Setting Facts Straight

Fun with Statistics:

While it's not a major problem with this presentation, I do think the use of statistics to push an obvious agenda should be called out.  Lustig presents 1985 and 2010 caloric intake and diabetes incidence (by %) and then shows that calories only increased by 8% while diabetes rates increased 727%!  Yikes, surely calories can't explain it, right?  I don't know, I haven't seen the data.  But I'm a bit mistrusting of Lustig setting this up and then stating that the increase in sugar consumption does correlate highly with diabetes and that it's 50X more potent in explaining diabetes compared with calories.  Now I doubt sugar consumption has increased by even 100% (doubling consumption) from 1985 to 2010.  Why no numbers?   I also have a hard time guessing at the statistical scenario that makes sugar 50X more potent in explaining diabetes.  When a correlation is done, there's a correlation coefficient, r or R, and R^2 is a value used to say X% of the variability in B is explained by its correlation with A.  I have a hard time believing that R's for calories and sugar are 0.1 and 0.7 respectively, giving R^2 of 0.01 and 0.49 respectively, approximating the 50 fold difference he reports.

The ABSURD Contention that Sugar is the only Foodstuff that is Fat + Carb together 

Let's repeat the direct quotation of what Lustig says in this regard.  After a food history lesson   where he says we became gourmets when we put fat+carb on one plate, and gourmands when we put fat+carb in one food.  A quick Wikipedia search tells me that in 1528 the Spaniards started sweetening chocolate.   But then: 

"Sugar because of its unique composition is the only food on the planet that is both fat and carbohydrate at the same time.  Even fatty fruits, coconut, olive, avocado have no carb.  There is no foodstuff on this planet that has both fat and carbohydrate at the same time.  It's one or the other, because that's evolution, that's nature, that's what God did."

It's true that few whole foods found in nature are high in both carbs and fats.  I don't think the human metabolism evolved or adapted to eating large quantities of both at the same time because of this fact.  But the oily fruits he describes do contain some carb, and we can add nuts and select legumes that also contain both.  Milk would be the only food I can think of is relatively high in both.  But Lustig is claiming that, say, a high sugar melon like a cantaloupe is a high fat + carb food?  Or frankly any fruit.  Bananas are high fat + carb?  He's using the fact that some fructose is converted to fatty acids through DNL after the food has been absorbed and metabolized to make a definitive claim -- biochemically inaccurate on its face -- that sucrose is both a carbohydrate and a fat at the same time.  NOT TRUE.

Fructose Metabolism again - de novo lipogenesis is not what it's cracked up to be in humans 

Lustig has been at this gig long enough to have investigated this further.  Several critics have pointed out factual errors enough times that he should have fixed this by now.  It's a "mistake" he may have made early on.  Now it's not a "mistake", it's a misleading lie told to convince you that sugar is inherently toxic by virtue of what it does to your mitochondria.  I imagine this is the sort of "white lie" that is tolerated by members working for some "good cause".  Please tell me how replacing the demonization of saturated fats and cholesterol with bastardized science to demonize sugar is productive. 

Fructose & Fatty Liver & Insulin Resistance 

 I'll give Gary Taubes this, he is usually pretty careful to add words like "probably", "could be", "might be" in with his theories.  Lustig does no such thing.  He speaks from a position of authority as if this is all settled science.  No doubt this is why his YouTube video went viral, and it sounds convincing until you take a closer look.  To me the whole sucrose = carb + fat claim is enough to just shut this guy off.   He's either not smart enough to understand basic biochemistry or he's being intellectually dishonest to hype fear.  I know where I'm leaning on that.   However even if we presume he's correct, that the majority of fructose going to the liver is turned to fat and causing fatty liver, the link between fructose per se (e.g. without caloric excess) and NAFLD is far from clear, and the link between NAFLD and insulin resistance is as well.   I haven't seen any evidence that DNL "constipates" your mitochondria, that's for sure!  

Just this morning I came across (and put it in the library):  The Problem of Establishing Relationships between Hepatic Steatosis and Hepatic Insulin Resistance.   Robert V. Farese, et.al.  Lead author affiliated with:  Gladstone Institute of Cardiovascular Disease, Department of Medicine, and Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158, USA.  Hmmmm.... interesting affiliation there, eh?

SUMMARY:  Excessive deposition of fat in the liver (hepatic steatosis) is frequently accompanied by hepatic insulin resistance. Whether this correlation is due to a causal relationship between the conditions has been the subject of considerable debate, and the literature abounds with conflicting data and theories. ...

CONCLUSIONS:  To date, no specific lipid has been shown to be both necessary and sufficient to cause hepatic IR. The available data indicate that the accumulation of neutral TGs is not causative. It also seems clear that, at the whole tissue level, excessive bioactive lipids, such as DAGs or ceramides, do not fulfill a strict causative relationship, as they are not always sufficient. Whether specific species of such bioactive lipids within specific compartments of hepatocytes can cause hepatic IR remains an active area of investigation.

Another possibility is that different routes lead to hepatic IR, and excess bioactive lipids act as contributing factors. Other processes, such as ER stress or inflammation, also may be sufficient as contributors in some circumstances. In this manner, the accumulation of different lipids, such as DAGs or ceramides, may act as contributing factors, which when combined with other contributing factors, result in a cellular state that is sufficient, but not required, to cause hepatic IR. ...

Fructose is only safe if you're starving or just ran a marathon:

What was I saying about exaggeration recently?  This is needless exaggeration.  First, there's a lot of evidence that regular moderate alcohol consumption can even be beneficial.   What's to say the same isn't true for fructose?  Not saying it is, but what's to say it's not?  But this is building on the only athletes can eat carbs meme I'm seeing bantied around these days.  As if you have to be training several hours a day to be "allowed" to oxidize glucose.  Nonsense.  We were more active in the 60's, but the percentage of athletes in the population wasn't higher yet we ate carbs and sugar.  This stuff is unnecessary hyperbole and it ultimately undermines Lustig's agenda.

Fructose is just like Alcohol:

I'm tired of this one.  First, because it's not true.  Fructose is metabolized into molecules that are considered benign by Lustig in the diet: glucose and saturated fat.  Further it is metabolized to synthesize glycogen.  Alcohol .... not so much!  So this graphic he uses rises to the level of deliberate deception at this point.

I'm not sure what I'll do with the rest of this series.  Perhaps do a highlights but I had a hard time slogging through it the first time.   This episode is enough to discredit this man and question the veracity of everything he puts forth on this topic. 

---

More:  Part III