Sugar substitute may not promote weight loss

A team of researchers from Massachusetts General Hospital have found a possible mechanism that may help explain why aspartame, a sugar substitute, does not help promote weight loss. Their report was published in Applied Physiology, Nutrition and Metabolism, and it explains that phenylalanine, a breakdown product of aspartame may interfere with the actions of an enzyme which prevents metabolic syndrome. Using mouse models, the researchers found that a diet with aspartame actually increases weight, whilst a non-aspartame diet does not.

During this study, a series of experiments was carried out, with one showing that the activity of an enzyme, known as IAP, was greatly reduced when added to a solution containing an aspartame sweetened drink, this was not the case in the sugar sweetened drink. This is particularly worrying as sugar substitutes are often used to promote weight loss by limiting the consumption of sugar. Now a number of epidemiological studies are looking into whether these substitutes are genuinely effective. The researchers want to highlight that other mechanisms may be involved, and this is only one such mechanism that may point to the use of artificial sweeteners being counter-productive.


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  1. Linda

    What about Stevia?

  2. Stefan Davis

    This is extremely interesting! I was always very curious, and a bit skeptical, of the effects of sugar substitutes, particularly aspartame. I know there needs to be more research conducted to find something more conclusive, but ultimately I think if you want a sweet drink you should have one with real sugar for now, as the effects of sugar are clearly documented and well known, but you should just limit your consumption. I’m looking forward to the publication of the newer studies.

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