sugars-and-sweeteners-header.jpg
Inside Our Food

Breaking Down Sugars and Sweeteners

Sweeteners are regularly used by those looking to reduce their sugar intake. But, how do sweeteners affect our body?

Sweeteners can create the same sweet taste many of us love, giving us the experience of eating sweet foods but with much fewer calories. But how do sweeteners achieve the same effect as sugar so lightly, and do they affect our bodies differently compared to sugar? 

Why Are Sweeteners So Low-Calorie?

Sugars like sucrose (aka: table sugar) bind to the ‘sweet’ taste buds on our tongue, activating them and sending signals to the brain - which we experience as a sweet taste.1 Sweeteners bind to these same taste buds far more effectively, meaning sweeteners can taste much sweeter to us than sucrose in much smaller amounts1  - for example, aspartame (a common ingredient in diet sodas) tastes up to 200 times sweeter than table sugar!

This means that we can re-create the same sweetness in our food by replacing lots of sugar with a tiny amount of sweetener, reducing the number of calories we’re adding. In addition, some sweeteners can’t be digested by our bodies, which means even the small amount of calories they do carry pass through our bodies without being absorbed. 

How Our Body Breaks Down Sugars and Sweeteners 

Sweeteners have different chemical structures to table sugar, and so despite similar effects on our taste buds, they aren’t broken down, digested or absorbed in quite the same way as sugars by our bodies. 

How sugars are digested and stored

Different types of sugar impact and are stored in our bodies in different ways. Sucrose, for example, is made of two sugar molecules: fructose and glucose. Fructose is sent to the liver to be broken down,2 while glucose is the sugar molecule that our body immediately uses for energy. Glucose is released from foods during digestion, raising blood glucose levels before it is absorbed by our cells or stored as glycogen in the liver or in muscles. 

How sweeteners are digested and stored

In most cases, because sweeteners are consumed in such small amounts, they have a minimal impact (if any) on blood glucose levels. In other cases, sweeteners like aspartame - commonly used in diet sodas - don’t cause blood glucose levels to rise because they’re made of amino acids (the building blocks of proteins), and so don’t release any glucose when broken down. Finally, some sweeteners may remain undigested and unabsorbed, therefore failing to raise blood glucose at all. This makes sweeteners an alternative means for people who are watching their sugar intake to enjoy sweet tastes without risk of high glucose intake so long as other foods they accompany diet products with don’t do this instead. 

Sweeteners Impact On Our Gut

The sugars and sweeteners in our diet can also impact our gut.3 For example, certain sweeteners like xylitol (commonly added to chewing gum) may cause laxative effects. This is because xylitol is a polyol,4 or sugar alcohol molecule, that is difficult for our bodies to digest. When sweeteners like xylitol move into our gut and remain undigested, the increased concentration of sweetener in the gut drives water to move into the gut via osmosis. With more water drawn into the gut, this may result in diarrhea. 

The Effects Of Sugars And Sweeteners On Hunger

Replacing sugar with sweeteners can also change how satisfying we find sweet treats. As we digest and absorb sugar, our blood sugar levels rise, which drives changes in levels of hormones in our blood that regulate how hungry we feel. 

For example, after we eat, our raised blood sugar levels cause our pancreas to increase its secretion of insulin (which contributes to feeling full) and decreased secretion of the hormone ghrelin and glucagon (which drives appetite). 

While some sweeteners, such as oligofructose, appear to cause the same hormonal responses from the pancreas and can quench our hunger,5,6 other sweeteners do not. Some sweeteners do not initiate the same response associated with feeling full because they either remain undigested or don’t contain glucose to cause the hormonal response from this spike. As well as raising blood sugar slightly, animal studies have shown that sweeteners like sucralose actually drove an increase in ghrelin secretion, which increases appetite despite the consumption of sweetened foods.5 

Read more about the issues with scientific research into the health impacts of sugars and sweeteners.

Replacing Sugar with Sweeteners 

For people monitoring their blood sugar, including diabetic patients, sweeteners are a way to keep enjoying the taste of sweet foods without ingesting large amounts of sugar.  However, if the sweet taste of sweeteners is coupled with a failure to drive hormonal responses that leave us satisfied, they may leave us craving more, even sweeter foods after a meal. Put simply, replacing sugar with sweeteners isn’t a ‘quick fix’ solution for everyone. 

Let us know what you think of sugars and sweeteners in your sweet treats in the comments below!

Related articles

Most viewed

Earth First

Sustainability of Protein Sources | Ask the Expert

Jane Alice Liu,Prof Mikael Fogelholm

What are the best eco-friendly protein sources? How much protein should you be having every day? Is…

Earth First

Plant-Based Iron Sources

Angelika Schulz,Klaus Hadwiger

As a central component of red blood cells (which store and carry oxygen through our bodies) iron is…

Earth First

Should We Bring Back The Buffet?

Dr Caroline Wood

Lavish, all-you-can-eat spreads are often a key feature of parties, weddings, hotel stays and…

Inside Our Food

The Global Nutrition Epidemic of ‘Hidden Hunger’

Dr Dora Pereira,Isabella Stelle

Historically, the World Health Organisation defined malnutrition as a lack of caloric or protein…

Inside Our Food

Cheese; to pasteurise or not to pasteurise?

Meghan Horvath,Luke Cridland

Since its discovery in the nineteenth century, the process of pasteurisation has helped preserve…

Inside Our Food

Olive Oil: The Science Behind Health Benefits

Julianna Photopoulos

Olive oil is a key part of the Mediterranean diet, thought to have health benefits such as lowering…

Earth First

Sourdough Starter: How it Works

Sedeer el Showk

Baking sourdough bread has become an increasingly popular pastime and source of comfort for many…

Earth First

Kimchi & Kombucha | How It’s Made

Kelly Oakes

Fermented foods like kombucha and kimchi are becoming more and more popular – but what does…

Inside Our Food

What Are Prebiotics | Foods and Supplements?

Lynn Liu

In the last few years we’ve seen emerging evidence on the importance of gut health to our…

Inside Our Food

7 Foods That Are Protein-Rich Sources

Lynn Liu

Every cell in your body needs protein in order to function well. It plays a key role in the…

Inside Our Food

Is Sugar The New Tobacco?

Silvia Lazzaris

Understanding the impacts of sugar on our health is not an easy task. Food science is complicated…

Human Stories

How is Vanilla Grown?

Samanta Oon

Sometimes called the “queen of spices”, vanilla is commonly used for its sweet flavour…

Keep updated with the latest news about your food with our newsletter

Follow Us