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Are sweeteners healthier than sugar?

Often when people try to cut down on their sugar intake they replace it with sweeteners but are the low-calorie alternatives as healthy as we think?

A diet high in sugar can lead to weight gain and result in serious health problems over time such as obesity, type 2 diabetes, stroke and heart disease. According to the World Health Organisation, the intake of sugars and excessive unhealthy foods have been linked to weight gain, as it provides a major and unnecessary source of calories with little or no nutritional value (2).

In 2018, 29% of adults in England were classed as obese, which is an increase from 26% in 2016 (3). The continual increase in obesity not only costs the NHS more than £6 billion every year, with indirect costs at an estimated £27 billion but it also claims at least 2.8 million lives worldwide per year (4,5).

These numbers alone show that we all need to cut down on sugar intake for the good of our health. However, when people commit to limiting their sugar consumption, they often turn to sweeteners to curb their sweet tooth but, are the low-calorie sugar alternatives as healthy as we think?

Let’s take a look at the benefits and drawbacks of both!


Sugar goes way beyond the traditional table sugar you pour over your cornflakes in the morning. Sugar is a class of carbohydrates that tastes sweet and it is also a quick and easy fuel for the body to use. Many types of sugar exist, and they occur both naturally and as ingredients in many foods.

The most recognisable type of sugar is sucrose. It consists of two simple sugars - fructose and glucose and is found naturally in fruits and vegetables. Foods containing these natural sugars tend to be low in calories and sodium and high in water content. 

Whereas, added sugars which are present in foods such as cakes and sugary drinks, are the sugars to be concerned about. Added sugars often contain high levels of fructose corn syrup, invert sugars, honey, agave and other syrups. During digestion, all these sugars except lactose break down into fructose and glucose.

Eating high quantities of fructose (as opposed to glucose, which is the main type of sugar found in starchy foods) can increase your hunger and desire for food. (6). Excessive fructose consumption may also cause resistance to leptin, an important hormone that regulates hunger and tells your body to stop eating (7).

Although sugars are not chemically produced, they are very high in calories. For example, 1 teaspoon of sugar contains 16 calories, so if you are putting 2 teaspoons of sugar in your 3 or 4 cups of tea per day you are consuming an extra 128 calories on top of the sugars you consume in the foods you are eating throughout the day.

Sugar not only increases your calorie intake if consumed in large amounts, but it can also contribute to acne and negatively impact your dental health (8,9).


Sweeteners are low-calorie or no-calorie chemical substances and are used instead of sugar to sweeten foods and drinks, stimulating a sense of sweetness during consumption.

Sweeteners not only exist as small, circular tablets that we drop into our favourite hot drinks, they are also found, often hiding, in thousands of everyday products, from drinks, cakes and chewing gum to ready meals, yoghurts and ice cream.

Like sugar, there are many different types of sweeteners including saccharin, sucralose, acesulfame K, aspartame, sorbitol and xylitol. 

As sweeteners contain little to zero calories per teaspoon it is easy to see why many people opt to use the alternative when trying to lose weight. Studies have shown that consumption of artificial sweeteners may reduce body weight, fat mass, and waist circumference (10). The amount of weight loss, however, depends on an individual’s diet and how much exercise they are undertaking, as well as their genetic make-up and metabolism.

The same studies also reported that consuming sugar-free versions of soft drinks can decrease body mass index (BMI) by up to 1.3-1.7 points (11). Yet, observational studies have found a link between consuming artificially sweetened beverages and obesity (12).

It is also believed that artificial sweeteners may have a negative impact on appetite, therefore, promoting weight gain (13). As sweeteners taste like sugar but lack the calories as other sugary foods, they’re thought to confuse the brain into still feeling hungry (14).

Furthermore, back in the 1970s, an animal study found an increased risk of bladder cancer in mice fed extremely high amounts of sweetener and since then the debate over whether sweetener can cause cancer has raged.

However, over 30 human studies have been performed since the ’70s and have found no link between artificial sweeteners and the risk of developing cancer (15).

Which is healthier?  

Whilst sugar and sweeteners both have negative side effects if consumed in copious amounts, they are safe to consume, and moderation is key.

If your goal is to lose weight or cut back on your sugar intake whilst still being able to enjoy the occasional taste of sweetness in your daily coffee, sweeteners are probably your best bet.

However, if you're not eating sugar to excess, and the rest of your diet is almost free of added sugars, a teaspoon or two of sugar in your tea each day will not exceed the recommended daily amount.