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artificial sweeteners: low in calories but high… in weight gain?

Low calorie artificial sweeteners–such as saccharin (e.g. Sweet N’ Low), Aspartame (e.g. Nutrasweet and Equal), or Sucralose (e.g. Splenda)–are used in countless food items including diet sodas and essentially anything labeled as “sugar-free” targeted to consumers as a strategy for reducing calorie intake and thus losing weight.

This is despite the fact that studies have shown numerous side effects to these sugar substitutes.  Most disconcerting: in regards to weight loss, studies have reported essentially no beneficial effects for artificial sweeteners.  And in fact, more recent studies have reported a link between use of these low calorie artificial sweeteners and weight gain.

Low-calorie artificial sweeteners have been linked to both increased appetite as well as metabolic changes in response to calories, both of which promote weight gain rather than weight loss. 

When people eat sweet foods, the sweet taste signals an impending high-calorie bolus to the body, which registers caloric fulfillment of energy needs and also induces metabolic changes for use of the incoming energy.  With use of these low-calorie sweeteners, these natural responses are disrupted because the body can no longer trust a sweet taste to indicate a high-calorie intake.  After a while, the body can no longer accurately gauge daily caloric intake, causing a rise in appetite while burning fewer calories. 

Check out the links below for more info:

These findings emphasize two interesting points:

1) There is an extensive but as of yet mostly uncharacterized connection between the nervous system and the gastrointestinal system.  The effect of artificial sweeteners is just one example of the significance of this neuroendocrine axis.  I actually find this to be one of the more interesting areas for future research with obvious clinical significance and almost immediate impact on the lives of people.  Here is a link to a review paper for those of you who are interested in learning more about this physiology:

2) Not only do low-calorie artificial sweeteners not achieve their designed purpose, but apparently do the opposite!  Moreover, these sweeteners have numerous other reported side effects and have been linked to other health problems.  To be fair, the jury is still out on a definitive answer to how sweeteners affect the neuroendocrine axis.  But I think it is fair to say that it doesn’t look promising.  In the medical scientific community at least, there appears to be a growing belief that these substances should be more closely monitored and regulated by the FDA.  However, this is highly unlikely to occur due to the size (i.e. dollar worth) of the sweetener industry…yet another example of the conflicting interests of public health and the dollar…

keywords: artificial sweetener, sugar substitute, dieting, weight loss, splenda, equal, sweet n’ low


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