Jun 26, 2012

Do artificial sweeteners lead to weight gain?

The personal genomics firm 23andMe recently released the results of a user survey indicating that the consumption of diet soda is very highly correlated with high body mass index (BMI).  You can read this surprising result here.
people who drink diet soda five or more times a day have an average BMI nearly 5 units higher than those who never drink diet soda. 
Of course, this could be because people who are obese are more likely to choose diet soda.  However, it fits very well with something I have suspected for some time now, that consumption of artificial sweeteners leads to weight gain.

A 23andMe survey revealed that consumption of diet soda is correlated with BMI.  (The cartoon is also from their site.)

Although I know of no data in support of this hypothesis, I will explain two reasons why I think it likely.

Taste.  Consumption of sweet foods leads to a preference for sweet foods.  This was directly addressed in a study by Sartor et al. (Appetite 2011), who found that "overweight/obese individuals are more implicitly attracted to sweet" and "one month of soft drink supplementation changed sweet taste perception of normal-weight subjects."  My own preferences affect my thinking on this.  While I truly enjoy the sweetness of a ripe peach, fresh sweet corn or dark chocolate, I find many popular foods (including soda and iced cupcakes) to be too sweet and truly unpleasant.  The idea here is that when someone consumes artificial sweeteners they get used to sweet flavors and come to enjoy sweeter tastes, which ultimately leads to the consumption of more calories.  For more on taste, including possible links to obesity, see the Outlook on taste in this week's Nature, especially a summary of research  on taste and obesity


Homeostasis. This is a similar idea, but involves unconscious processes.  The gut is filled with sweet taste receptors (Dyer et al. Biochem Soc Trans. 2005). Although I don't know what they are doing there, it seems likely that information from these receptors is used to regulate appetite, or metabolism, or both.  If your gut is constantly full of sweet flavors, then they will be ignored.  The sugars released from real food will not make you feel satisfied, or will be improperly dealt with in some other way.  The body's homeostatic mechanisms are complex and I don't claim to understand them, but I do suspect that artificial sweeteners disrupt the natural response to food and contribute to craving and binge eating.  

2 comments:

Unknown said...

ste Fasting is half of patience, and patience is half of faith. There is one full month in every year in which fasting is recommended for Muslims all over the world. As the month is a lunar month, so it keeps changing around the year in connection to the solar months. This creates a worldwide balance for the worshippers. Sometimes the fasting in winter months is easy as far as the days go, in comparison to the long winter nights, while during the summer months the days become long and exacting. As the lunar months keep spinning around the year, so Muslims in all parts of the world have some periods of easy fasting and some of troublesome fasting.

Unknown said...

This question, or the more general one of whether artificial sweeteners are unhealthy, was addressed recently in the
New York Times when four scientists responded to a poorly researched op-ed that advised drinking artificially sweetened drinks. Altogether, they cite four studies.
1) Consumption of sugar sweetened beverages, artificially sweetened beverages, and fruit juice and incidence of type 2 diabetes: systematic review, meta-analysis, and estimation of population attributable fraction.
2) Artificial sweeteners induce glucose intolerance by altering the gut microbiota.
3) Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements.
4) Ingestion of diet soda before a glucose load augments glucagon-like peptide-1 secretion