Which One is the Real Bad Guy: Sugar or Fat?

This month, I am on Endocrinology at work, where I have seen tons of diabetics, Metabolic Syndrome patients (patients with something of a quad-fecta: high blood pressure, high cholesterol, obesity, and diabetes), and obese patients.  I have been absolutely shocked at some of the diet recommendations!  My attending promotes an Atkin’s-style diet (low carb, high protein and fat), which I thought was thoroughly debunked and has been regarded as unheathy for decades!  He is met with lots of resistance from everyone, including myself.  He even managed to provide multiple medical studies promoting the efficacy and healthful effects of a low-carb diet…and my interest was piqued.  Could he be right?!  As it turns out, he’s not the only endocrinologist who believes this- many, many of them do!  Why?!

An endocrinologist from UCSF, Dr. Robert Lustig, gives lectures to the public called “Mini-Medical School.”  He gave one such lecture on how and why sugar and high-fructose corn syrup are the culprits to our nationwide epidemic of obesity and diabetes, providing the biochemistry and necessary studies to back up his claim.  Very compelling speaker, very compelling argument.  Here is his Mini-Medical School Lecture video:
Sugar: The Bitter Truth

The video is a full hour and a half, but I thought it was totally worth my time.  Not everyone has that kind of time, so to paraphrase very basically, what he describes is that table sugar, or sucrose, is 50% glucose and 50% fructose.  High-fructose corn syrup (HFCS) is roughly 55% fructose and 42% glucose.  The fructose in these 2 substances is metabolized quite differently from the glucose, in that glucose is metabolized mostly in the muscles and used for energy, while fructose is metabolized through the liver and is used for fat storage.  (Again, very basic- for the full details, I refer to the video).  The fructose, he shows, if used in large amounts, is implicated in the development of high blood pressure, diabetes, obesity, and high cholesterol, all of which comprise Metabolic Syndrome.  He does a much better job of explaining the detail, and it is a must-see video for anyone interested in the sugar debate. 

In the end, he promotes a low-sugar diet.  He promotes cutting out all sugar and HFCS, including (and maybe especially) juices.  Fruits are ok, however, even though they are a natural source of fructose, because they are coupled with fiber, which slows the insulin spike caused by a carbohydrate meal, serve to stabilize your blood sugar.  Juice, even unsweetened, strips the fiber away from the liquid & concentrates the amount of fructose per serving- even worse!  Not to mention that we’ve all seen the shameless commercials from HFCS makers stating that HFCS “isn’t that bad for you!”  I wanted to see what else they were saying about HFCS, so here’s their website:

Here are my answers to each of their “myths”:
1. Sugar is “healthier” than HFCS, which they say is untrue, because they are chemically so similar.  I agree that sugar is not a healthy alternative to HFCS, but this website completely ignores the fact that they are both bad for you.
2. HFCS is to blame for obesity and causes diabetes, to which they answer that there is no scientific evidence that HFCS directly causes those disorders.  Sure, no study shows that HFCS alone causes DM or obesity, but there is mounting evidence that implicates sugars and sweeteners as a large group.  So in the first myth they taut how similar HFCS is to sugar, but in the second myth, they say it’s not similar to sugar.  Pick a side.
3. HFCS is not natural, to which they say it meets FDA standards on what to call “natural” (don’t even get me started on that loaded word), and since it’s a product of corn, it’s “natural.”  Nevermind that it’s processed and refined.
4. HFCS is sweeter than sugar, to which they answer that they are the same.  This is an outright lie.  Sugar gets 100 on the relative sweetness scale, which HFCS gets 120, and fructose gets 140.  See:
Relative Sweetness Scale
and that’s where I’ll stop with their “myths” before I hurt somebody.  It seems like a lawyer put together that list and carefully answered each myth, bending the truth for the company’s needs.

Anyway, a New York Times article made its way across my desk this morning, which spoke about this very subject (interesting timing, as usual).  It is written about Dr. Lustig’s lecture:
Is Sugar Toxic?
and it opened my eyes to a decades-old debate about diets: which are more effective: low-fat, high carb (read: high sugar) diets or low sugar, high fat/protein diets?  It referenced this older NYT article on the subject, as well:
What if It’s All Been a Big Fat Lie?

With an almost conspiratorial tone, both articles review the hostility with which the medical community views the Atkin’s Diet, and promotes a low-fat diet.  For years, the prevailing wisdom has been that a low-fat diet is the ticket to avoiding obesity, diabetes, high cholesterol, and high blood pressure.  However, everything presented here (the video, all the articles) and in my attending’s office actually show the opposite is true: there is mounting evidence (and has been for decades) that a high protein/fat, low sugar/carb diet promotes low cholesterol, low blood pressure, slimmer waistline, and less sugar intolerance.  In addition, a low fat, high carb/sugar diet has been accepted in the medical community as having failed to prevent any of those conditions!!  I am so floored! 

So who wins the great debate?  High carb/sugar, low fat/protein?  Or low carb/sugar, high protien/fat? how will I apply all of this information?  I have taken a middle of the road approach: I already held that low or no sugar diets are crucial to preventing diabetes, and yes, diabetes is a risk factor for heart disease, so no arguments from me for adopting a low sugar diet.  Does that mean I will pick up the bacon and all you can eat steaks?  No.  I cannot ignore the mountains of evidence showing that saturated and trans fats cause heart disease, too.  But I will increase my consumption of the “right fats:” avocados, extra virgin olive oil, nuts, fish.  But does that mean that I am erasing carbs from my diet, too?  What about whole grains?  The answer is again, no.  The fiber inherent in whole grains and veggies and fruits stabilizes the blood sugar and decreases those insulin spikes.  And I refuse to overlook the piling evidence about how high fiber diets prevent colon, breast, ovarian, and endometrial cancers, oddly enough.  So I will just continue to eat the right carbs: whole grains, fruits, vegetables, and avoid refined sugars, flours, HFCS, and juices.  So I chose my own diet: low bad fat/high good fat, low bad carb/high good carb diet.  There, I win.

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