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 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 sugary foods and drinks 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. Sugars are simple carbohydrates which taste sweet and are quick and easy fuels for the body to use. Many types of sugar exist, and they occur both naturally, and as added ingredients in many foods.

The most recognisable type of sugar is sucrose. It consists of two simple sugars (known as monosaccharides) - fructose and glucose. Although sucrose can be found naturally in fruits and vegetables, it is also the table sugar which we usually add to foods to sweeten them.

Other types of sugar, which are added during manufacture to foods such as cakes and sugary drinks, can come in the forms of corn syrup, invert sugars, honey, agave and other syrups. During digestion, all these sugars break down into their simple monosaccharides such as glucose and fructose.

Sugars can contribute significant calories into your day. 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 calories you consumethroughout the day.

Sugary foods are also tastier than non-sugary foods, which can ‘trick’ your brain into over consuming food. Glucose is the primary fuel source for the body, which explains why we get sugar cravings and sometimes want to put the ‘share’ bag of treat down – but simply can’t!

The impact of sugar on dental health is also well established, as sugar has been identified as a leading cause of tooth decay.

To alleviate the undesirable effects of sugar on our bodies, it is currently recommended that we eat no more than 90g of sugar a day, but importantly, get no more than 5% of our energy in the day from ‘free sugar’. Free sugar is defined as those added to food (e.g., sucrose (table sugar), glucose) or those naturally present in honey, syrups and unsweetened fruit juices, but exclude lactose in milk and milk products as well as those sugars contained in fruit that is still intact – i.e. not juiced (15).

How do you ensure you get no more than 5% of your energy (calories) from free sugar? It may seem tricky to work out, but the truth is that it very easy to do, and most of us get more than enough ‘free sugar’ without even thinking about it. To make sure you do not exceed the recommendations, it may be useful to actively try to cut down the amount of ‘free-sugar’ in your diet, here are some handy tips:

  • Limit fruit juices and smoothies to 150ml a day, or even better opt for water.
  • Read the ingredients list. ‘Naturally occurring’ added sugars, such as syrups, still count towards your free sugar intake. In addition, any ingredient names which end in ‘syrup’ or ‘-ose’ are probably added free sugars! The higher up in the ingredients list they are, the more they contribute to the overall food ingredients.
  • Wean yourself off the amount of sugar you add to your food and drinks gradually; do it in small stages over time. Your body will not notice small changes, and, in the end, you probably won’t notice that you’ve cut it out completely!
  • Choose to eat complex carbohydrates with a low Glycaemic Index (GI), these foods will slowly release sugar throughout the day, avoiding large spikes and falls in blood sugar levels, and therefore reduce your cravings for sweet treats.


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 added into 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, over usual sugar, may reduce body weight, fat mass, and waist circumference (10). The amount of weight loss, however, depends on how much sugar they have substituted for sweetener.

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 an association between consuming artificially sweetened beverages and obesity (12). This may be due to an increasing preference for sweeter foods, but importantly, an association does not mean it is a causal link.

Some researchers suggest that artificial sweeteners may have a negative impact on appetite, therefore, promote 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, some animal studies have 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 taken off.

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). Sweeteners have been reviewed and declared safe by The European Standards Agency (EFSA) who research and regulate the safety of our food ingredients.

So which is healthier?

Whilst sugar and sweeteners can 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.

















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