How Diet Fizzy Drinks May Befuddle Our Brains

| January 21, 2017

I mentioned in my last blog post how the UK government is hoping for some big health benefits from its sugar tax on the fizzy drinks industry, due to come into force next year. But what will be the real effects of switching from high-sugar drinks to artificially-sweetened diet versions?

As I mentioned in earlier posts here and here, artificial sweeteners have been shown to disrupt blood sugar control and cause type 2 diabetes. They have also been found to induce weight gain. Part of the reason is that these very unnatural chemicals alter our eating behaviour in unhealthy ways.

One effect of artificial sweeteners is to over-stimulate our sweetness sensors, changing the way we taste food. People who routinely drink diet fizzy drinks could find that healthy and nutritious food items, such as vegetables, become much less palatable.1 Artificial sweeteners in drinks simply intensify cravings for sweet, sugary foods of all kinds.

Another effect that artificial sweeteners have is to disconnect the sweet taste from energy content. Our brains have sophisticated feedback mechanisms to ensure that the enjoyment of sweet taste is balanced by a feeling of “reward” and satiation after eating a certain amount. Faced with a box of chocolates, most of us know there comes a point when the thought of eating another one is no longer appealing!

Research using MRI scans of the brains of human volunteers has shown that sucralose (Splenda), for instance, activates this feedback mechanism much less strongly than sugar.2 This means that when foods are artificially sweetened, more needs to be consumed before those sweet cravings are satisfied.

Added to these physiological changes, we often like to fool ourselves that picking a diet drink over the high-sugar version is healthier, allowing us to rationalise that it’s okay to have that muffin or doughnut alongside it!

So, the UK sugar tax could be doomed to fail. Only by gradually reducing people’s sweetness expectations, by lowering levels of both sugar and artificial sweeteners, will any progress be made in the struggle against obesity and type 2 diabetes.

In my next blog post, I’ll be returning to the topic of exercise, with the welcome news that even moderate amounts could help to reverse memory problems linked to type 2 diabetes.

Wishing you the best of health,

Martin Hum
PhD DHD Nutritionist
for Real Diabetes Truth

Bear in mind we are not addressing anyone’s personal situation and you should rely on this for informational purposes only. Please consult with your own physician before acting on any recommendations contained herein.


1. Yang Q. Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings. Yale J Biol Med. 2010; 83(2):101-108.

2. Frank GK, Oberndorfer TA, Simmons AN et al. Sucrose activates human taste pathways differently from artificial sweetener.Neuroimage. 2008; 39(4):1559-1569.

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Category: Diabetes News Views

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