Artificial sweeteners increase your risk of weight gain.

Artificial sweetener sales are booming market.  Even though sales have decreased in the United States in the past 3-5 years, the market remains a multi-billion dollar industry worldwide.  Nonnutritive sweeteners, such as aspartame, saccharin, sucralose, and stevioside, are widely consumed, even though their long-term health impact is uncertain.  Many of the manufacturers claim that their sweetener is the safest and most natural.  The only one who can truly make that claim, and it is sugar, and unfortunately even the calorie-free look like they contribute to weight gain and obesity.  

Artificial sweeteners that have zero calories causing weight gain and obesity just do not make any sense to the average person.  I fought to find a mechanism until now.  I found an interesting study on aspartame​[1]​.  This study showed that aspartame blocks a key enzyme in the small intestine that prevents glucose intolerance and obesity in mice.  This change may be indicative of why aspartame usage does now promote weight loss.  Another study looked at the effects of non-nutritive sweeteners on insulin levels after consumption and found that insulin levels increased in response to an artificially sweetened drink​[2]​.  Although they showed no change in appetite, an increase in insulin should cause a rise in appetite.  Another study looked at sucralose and found that use was associated with a higher caloric intake​[3]​.  

A new study published in July of 2017 in the Candian Medical Association Journal appears to point to artificial sweeteners as a potential cause of obesity, diabetes, high blood pressure, and heart disease​[4]​.  The study is a meta-analysis of prior randomized controlled trials and cohort studies to determine whether routine consumption of non-nutritive sweeteners was associated with long-term adverse cardiometabolic effects.  The researchers searched MEDLINE, Embase, and Cochrane Library for studies that evaluated interventions for nonnutritive sweeteners and prospective cohort studies that reported on the consumption of non-nutritive sweeteners among adults and adolescents.  The randomized controlled studies failed to show a significant difference, but a review of cohort studies found that consumption of artificial sweeteners was associated with a modest increase in body mass index, waist circumference, and weight.  

The bottom line:  Although the evidence is split, it is clear in the review of the cohort studies that observational data suggest that routine intake of nonnutritive sweeteners may be associated with an increased risk of obesity. Further research is needed to characterize the long-term risks and benefits of nonnutritive sweeteners fully.  More research needs to be done, but it is clear that artificial sweeteners are not the answer for weight loss and appear to cause weight gain.  If you need to add a little sweetener to your tea or coffee, consider adding a little honey or brown sugar, but remember to go light on it.