You want to lose weight, so you start trying to cut calories. The most obvious starting place seems to be switching from high-calorie foods with sugar to foods with zero calorie sweeteners, like aspartame. Better known by brand names, such as Equal, NutraSweet, and Spoonful, aspartame seems like a no-brainer. Fewer calories equals weight loss, right?
In fact, study after study has shown just the opposite. Aspartame and all other artificial sweeteners lead to weight gain, not weight loss. So, not only may aspartame be the most toxic additive to foods, instead of helping you lose weight, it actually makes it even tougher to lose it!
What's Going On?
Dr. Qing Yang, of the Department of Molecular, Cellular and Developmental Biology at Yale University, explains.  He suggests that multiple factors are at play:
- Artificial sweeteners do not activate the food rewards pathways in the brain. Functional MRIs have shown that the appetite suppression brought about by real sugar doesn't happen with artificial sweeteners, even if they contain calories. Therefore, there is nothing to tell you that it's time to stop eating. You remain hungry!
- Studies have shown that aspartame increases hunger more than glucose.
- Anything that tastes sweet enhances appetite, no matter what makes the food sweet. So, there's a double whammy with artificial sweeteners. Not only is your appetite increased, as it is with sugar, but there's no signal telling you to stop eating.
- Repeated exposure to sweets encourages craving for sweets. Because people believe that there's no harm in eating aspartame-laced foods, they tend to eat even more of them, resulting in a vicious cycle of increased craving.
It Isn't All About Calories
Studies have shown that not only does aspartame cause weight gain, it causes greater weight gain than a diet with the same calorie intake, but no aspartame.  So it's becoming more and more clear that there's a lot more to weight reduction than counting calories.
Aspartame and Fat Storage
Aspartame contains the chemicals phenylalanine and aspartate. Both of these substances increase fat storage. They interfere with insulin and leptin, which control how fat is handled, whether it's stored, how it's stored, where it's stored, and how it's used.    Fat metabolism is deranged by aspartame, with the inevitable result of causing people to pack on the pounds when they're trying to do exactly the opposite.
Aspartame: Fat-Free or a Fat Pack of Lies?
The fact is that aspartame is not the shortcut to weight loss that marketers want you to believe. The only true thing about the advertising is that it doesn't have any calories. But, as you've seen here, weight loss is about more than calories.
In short, aspartame makes you fat by:
- Keeping you hungry
- Preventing you from knowing when you've eaten enough
- Increasing your appetite
- Making you crave more sweets
- Deranging fat storage
Of course, I don't advise eating sugar. It causes more than enough problems. However, if you cannot control your sweet tooth, sugar is less harmful than aspartame — or any other artificial sweetener – and probably won't cause as much weight gain. Isn't it amazing that a product sold to help you lose weight actually has the opposite effect? Worse than that, it actually makes you crave more of it, so you'll end up getting even fatter.
What a fat pack of lies!
- Qing Yang. Gain weight by "going diet?" Artificial sweeteners and the neurobiology of sugar cravings: Neuroscience 2010. The Yale Journal of Biology and Medicine. June 2010.
- Feijó Fde M, Ballard CR, Foletto KC, Batista BA, Neves AM, Ribeiro MF, Bertoluci MC. Saccharin and aspartame, compared with sucrose, induce greater weight gain in adult Wistar rats, at similar total caloric intake levels. Appetite. January 2013. doi: 10.1016/j.appet.2012.10.009.
- Nuttall FQ, Schweim KJ, Gannon MC. Effect of orally administered phenylalanine with and without glucose on insulin, glucagon and glucose concentrations. Hormone and Metabolic Research. August 2006.
- Schulpis KH, Papakonstantinou ED, Tzamouranis J. Plasma leptin concentrations in phenylketonuric patients. Hormonal Research. 2000.
- Reinehr T, Schmidt C, deSousa G, Andler W. Association between leptin and transaminases: 1-year follow-up study in 180 overweight children. Metabolism. April 2009. doi: 10.1016/j.metabol.2008.11.007.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.