Popular Science looks at the Downsides of using Artificial Sweeteners

Bad news about artificial sweeteners has been making the rounds for decades.  One never knows whether this sort of negative publicity is being supported by the Sugar Industry, or by some similar outfit with a vested interest.  Always beware.  This most recent article in Popular Science magazine (which has been known to sensationalize some stories, resulting in confusing readers without a strong science background, but has also been known to bring great news stories to public attention) says that it is possible that heavy use of artificial sweeteners can lead to increased fat deposits.

Let's look at some of the basic axioms.
* Sugar contains calories, and drinking lots of soda with real sugar does lead to obesity, unless the calories are used up with exercise.
* Unused calories are stored in the body as fat.  Ounce for ounce, fat contains far more calories than sugar and carbs, so fat cells are like zip drives for large calorie files.  To burn off fat, you must first unzip the fat files (essentially by about 28 minutes of exercise using sugars, at which point the stored fat begins to get used for the exercise.  This is why they always suggest that you should exercise for at least half an hour).
* When Insulin in the bloodstream finds more sugar than the body can immediately use, it triggers the conversion into fat.  This is new information to me; I did not realize that Insulin had anything to do with conversion of sugar to fat.  I could have misunderstood whatever I read, so take this message with a little caution.  It is an important point that needs to be clarified, so don't put off for the indefinite future doing your own research about it.  Do as I say, not as I do.
* Artificial sweeteners contain very few calories, so, yes, they don't supply the body with unnecessary calories.
* When any normal person eats a little sugar, there are brain centers that issue a 'satisfaction' or 'reward' signal, which normally leads the person to slow down eating.  Artificial sweeteners don't do that (or at least not as effectively), so, apparently there's no negative feedback to the eating loop; your system could get stuck in the 'eat more' position.  (More about negative feedback at the end.)
* Eating anything sweet--both sugar and artificial sweeteners--stimulates the body into producing Insulin.  Insulin is, as Popular Science, and similar articles in WebMD and the New York Times explain, a sort of key that unlocks muscle cells into opening up, and allowing sugar to enter and fuel muscle activity.  (For Type II diabetics, this key doesn't work very well.)

Wait a minute.  This means that if you use Artificial Sweetener, the Insulin production is triggered, but finding no sugar, the Insulin encourages storage of sugar as fat.  But there isn't any sugar!

Actually, there is.  People oversimplify these things for the benefit of us laymen; it is never the case that there isn't any sugar in the bloodstream; there's always a little.  I was recently in the emergency room being looked at by the doctors.  I was hoping that they would admit me, because I was in pain!  At first they said: this is simple; we can send you home soon, and you can check in with your general practitioner in the morning.  This is not an emergency.  But for various reasons my diabetic medication was reducing my blood sugar levels too aggressively, which sent the ER doctors into a panic.  Why?  There always has to be some sugar in circulation, otherwise the brain and the heart won't have the sugar they need to work.  Yes, the brain runs on sugar, which means, my young padawans, don't try to take a test on an empty stomach; your memory and your reasoning centers need a little sugar to work, and one expects that a test would involve brainwork.

So, drinking a lot of artificially sweetened soda can generate a brief glut of Insulin, which tries to package the little sugar there happens to be lying around into fat cells.  Once the sugar level falls to critically low levels, you lose consciousness, and if the Insulin burst is extremely large, the body will shut down to painfully low levels.  Finally, the liver has emergency stocks of sugar that it releases, to prevent additional damage, but I don't understand enough of those matters to give you an accurate description of them.

The "Artificial Sweeteners → Fat Cells" effect appears not to have been established experimentally, or at least I don't understand the degree to which it is just a conjecture.  But I believe that there is some evidence that heavy drinkers of artificially sweetened soft drinks do gain weight over time; I'm just not certain whether what I described is the actual mechanism.

There is yet another effect that some people will find more persuasive than others.  If we eat a normal healthy diet, our intestines will contain certain beneficial bacteria that humans have evolved with, over the millennia.  These bacteria help digestion, and are even considered to help people with maintaining emotional balance.  It sounds like something out of a Woo Woo publication, but I have never read any scientific article that denies this statement.  Unfortunately, large levels of artificial sweeteners are said to, at the very least, interfere with this balance of so-called intestinal flora (because bacteria are considered to be plants, not animals), and at the worst, kill them off, and introduce harmful bacteria instead.  This is clearly a broad generalization because there are scores of varieties of both kinds of intestinal flora (good and bad).  Many of your friends probably consume yogurt, and Kim Chee, and Kombucha, all foods that are considered to encourage good bacteria in your intestines.  Since you can control this balance only indirectly, some people consider that the whole thing is not worth bothering about.  I'm not going to weigh in on it, because each person addresses the matter in a different way, and the suggestions I give may not work.  However, note that acute diarrhea, and strong antibiotics, both deplete your intestinal flora, and you need to work hard to restore them, if you care.  By the way, from all I have read, it appears that you need to eat yogurt pretty aggressively (at least two containers per day of yogurt advertised as containing live bacterial cultures) to make a difference in your good bacteria levels.

For the lazy executive: food with just a little sugar and no artificial sweeteners is much better for anyone than anything with artificial sweeteners.  If you want to compromise, cut down severely on food--and especially beverages--with artificial sweeteners.  We've known that artificial sweeteners have bad effects, but it looks as though they have worse side effects than we initially suspected.

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