Tuesday, July 5, 2011

Diet Soda

Recently  Justin24601  wanted to know what I thought of this article about diet soda http://articles.latimes.com/2011/jul/01/news/la-heb-diet-soda-weight-gain-20110701 .  Happy to address it Sir!

What I like

-"Note that this doesn’t mean artificially sweetened sodas make you gain weight. (See "For the record" below.)* As Richard Mattes, a nutrition scientist at Purdue University, points out: Heavy people simply might choose to consume diet drinks more."
YES! Correlation is not causation!

-"Mattes has studied how artificial sweeteners affect appetite and food intake. He believes that many studies reporting a link between diet soda and weight gain are actually hitting on a behavioral phenomenon—people think they can eat more calories because they’ve swapped their regular soda for a Coke Zero.
“That’s not a fault of the product itself, but it’s how people chose to use it,” he says. “Simply adding them to the diet does not promote weight gain or weight loss.”

The second to the last sentence sums it up beautifully. I really don't feel I need to explain it any further but will if requested.  Unfortunately, that's not an exciting headline and won't sell anywhere near as many papers as "Diet Soda Makes You Fat".

Starting to come off the rails

-"In rodent studies, researchers have observed artificial sweeteners stimulating cells in the pancreas to change insulin secretion, altering the pH in the gut, and affecting hunger-regulating cells in the brain. Fowler and colleagues also reported this week that diabetes-prone mice exposed to aspartame for three months had higher blood-sugar levels than those not exposed at all"

Not a fan of rodent studies when talking about humans but the bigger issue here is that insulin actually blunts appetite, not increases it.  James Krieger, who wrote the phenomenal series on insulin addresses this. James cited this study http://www.ncbi.nlm.nih.gov/pubmed/16933179?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=66 but again, it's well known, at least among professionals, that insulin is an appetite suppressant, so unless the change is a drop in insulin levels (which I'd bet a dollar to a dime that's not what they're implying), I fail to see how that's concerning.  What else were done to the mice?  Are we saying the only different variable was aspartame exposure?  I doubt it but who would know since they didn't list which studies they were talking about.

-Dariush Mozaffarian, a Harvard epidemiologist who recently studied how a long list of food and drinks contribute differently to weight gain, says zero-calorie soda could be a good choice for people trying to lose weight, calling it an “intermediate step” to going “cold turkey” with sweets and soda.
“Artificial sweeteners may be a good short-term option to bridge people away from refined sugars, but consuming moderate or high amounts long-term should be avoided as possible," he wrote in an email.
The main issue, he said, is again, less about biological reactions than about our perception of sweetness: “We don't know how consuming artificially sweetened drinks and foods alter tastes and preferences for other healthy foods, especially in children.  For example, do apples or carrots taste just as sweet to someone who consumes high amounts of artificial sweeteners?"

I enjoy Mr. Mozaffarian's work but this is not his best stuff.
Let's break this down a bit:
1. Refined sugars are bad at least in the context of people that are trying to lose weight/maintain weight because on a limited calorie budget, they're calorically expensive and don't give you much bang for your buck.  Agree with Mr. Mozaffarian so far.
2. Why do we need to bridge away from sweetness if the sweetness we enjoy is calorie free?
3. Does anybody really think that they eat less carrots and apples because they drink diet soda?  Come on!  Think about who you see that drinks diet soda? People trying to stay thin/maintain weight and people trying to lose weight.  Think about those two populations relative to their fruit and vegetable consumption.  One usually already has the good habits formed and the other is drastically trying to increase it because they're "healthy" they're "low calorie", their trainer told them they must eat them, etc..  Carrots and apples shouldn't be thought of as sweet foods.  it's like going to school to be a social worker and being pissed off that you're not making six figures.  How about educating on the real benefits of fruits and nonstartchy vegetables instead of trying to paint them as something they're not!

-Diet soda in and of itself can not and will not make you gain weight (fluid weight excluded).  It is physically impossible.
-We can blame diet soda for increasing our sweet expectations or we ask the better questions like "why do I expect carrots to taste as sweet as soda?" or better yet "Why do I need sweet foods all the time?".  In my experience, obesity almost always has a mental health component, yet that is rarely addressed.  The fact that we're even discussing if a zero calorie product can cause weight gain proves this in spades.  We can call it altered taste perception if we want but the bigger issue is people are overconsuming calories, for a variety of reasons (emotional pain, boredom, habit, etc..), and that is what needs to be addressed.  Don't get me wrong, I like salty, fatty, and sweet foods (the terrible synergist combination!) and I certainly like them more than carrot sticks but I can control myself, not because I just have so much willpower but because I'm not eating as a coping mechanism.

In closing, I hope this was helpful and I look forward to your comments.



  1. Thanks for this informative article about diet soda, People's Dietitian. I have a question. I heard that when you eat celery, you burn more calories than you consume. I am so excited I have purchased several stalks of celery and am enjoying it so much, especially as I love dipping it in buttermilk Ranch dressing. I'm waiting for the pounds to come flying off!

  2. People's Dietitian,

    From a more general nutritional standpoint and based upon what the studies show as an insulin increase causing appetite suppression what are your thoughts related to these effects of soda/diet soda:
    1. Suppression of appetite due to diet soda consumption giving a false sense of being "full" with a nutrient empty food/beverage in place eating even a moderately "healthy" snack/meal.
    2. Using Diet Soda as a thirst quencher instead of good ole fashioned water and subsequently its effect on the metabolic process.

    Basically under the realm of both points that while Diet Soda (from my point of view) doesn't necessarily directly cause weight gain but rather inhibits the consumption of better alternatives and good nutrient practices to ensure an efficient metabolic process. Thus I refer to the People's Dietition to set the record straight. Great post though. And that Jadamcarter fellow is one weird dude!

  3. jadam, I hope you are a patient man