Do low-calorie sweeteners make you fat? Controversy and confusion over the role of high-intensity sweeteners in weight management

By Katy Askew

- Last updated on GMT

Pic: iStock/Yemchuk
Pic: iStock/Yemchuk

Related tags reformulation sugar-reduction High intensity sweeteners

The war on sugar continues to gather steam as increasingly health-conscious consumers seek to limit their intake by opting for products that are perceived as healthier. But controversy continues to swirl over the impact of high intensity sweeteners - a popular reformulation option - on health.

In Europe, two-thirds of people claim they are trying to lower their sugar intake, New Nutrition Business found in recent consumer research. “Sugar now occupies the place of the dietary demon that fat occupied 20 years ago,”​ emphasised Julian Mellentin, Food and Beverage Consultant, at the insight provider.

Public health communicators have vociferously advocated against food products that are high in sugar and the consumption of which has been linked to the pandemic of dietary related non-communicable diseases sweeping western markets, such as obesity and type 2 diabetes.

Internationally, Europe now has the highest number of food and drink launches with low or no added sugar labelling. Juice drinks, snacks, sugar and gum confectionery lead the way in terms of categories containing such claims.

This reflects the approach adopted by many within the food sector, which is focused on developing products that contain less refined sugar – but which also retain the taste and mouthfeel shoppers are accustomed to.

Reformulation appears to be broadly supported by regulators also. In the UK and Ireland, for instance, a sugar tax on soft drinks was introduced in 2018. Public Health England also set out a goal to reduce 20% of sugar from the food industry by 2020​ from the baseline set in 2015. 

However, Meleni Aldridge, executive coordinator at the Alliance for Natural Health, argues that the addition of sweeteners to food formulations are actually ‘part of the obesity problem’ – not the solution.

‘Big Foods artificial sweeteners are killing us’: Alliance for Natural Health

sweet beverage drink fizzy sugar

In an article published by the Alliance for Natural Health, Aldridge cites the ‘selfish brain’ theory​, which suggests that ‘brain occupies a special hierarchical position’ when it comes to the regulation of energy supply.

In short, Aldridge argued the brain is tricked into expecting a higher energy intake when products made with artificial sweeteners are consumed. This, she suggests, actually creates a negative feedback loop that results in cravings and higher calorie consumption.

“Glucose is the reference for the sensory area of the hypothalamus that tells you when you’re satiated (full). Glucose is less sweet than sucrose or fructose, having a ‘sweetness factor’ (a measure of relative sweetness) of 0.7, as compared with 1.0 for sucrose and 1.2 for fructose. Dietary carbohydrates, such as glucose and fructose, yield the same energy; about 4 kcal of energy for every 1 g.

“Throughout evolution the brain has become accustomed to the fact that the sweeter a food, the more calories it’s likely to yield. So it’s adapted to ‘expect’ more calories from sweet foods. Non-nutritive sweeteners available today (saccharin, aspartame, stevia, sorbitol and xylitol to name a few) pack an enormous wallop of sweetness, but no calorific reward to go with it. This creates a situation in which the brain is literally expectant and never reaches satiety, creating cravings to keep eating.”

‘The evidence does not support this suggestion’: Tate & Lyle

This conclusion was – perhaps unsurprisingly – rebuffed by ingredient supplier Tate & Lyle, which produces a range of reformulation solutions for food industry customers.

stevia sweetener extract sugar Heike Rau
Stevia is a popular high intensity sweetening option ©iStock/Heike Rau

“The evidence does not support this suggestion. Research shows that high-intensity or low calorie sweeteners do not increase hunger, nor create a desire for more sweet food, and therefore do not lead to weight gain,”​ Kavita Karnik, vice president of global nutrition and open innovation at Tate & Lyle, insisted.

Indeed, Karnik was quick to emphasise the beneficial role that sweeteners can play in weight control. “Research shows that high-intensity/low-calorie sweeteners can satisfy a desire for sweetness without the calorie intake that comes with sugar. They can therefore help people maintain a balanced diet and control their weight,”​ she told FoodNavigator.

The characteristics of low calorie sweeteners also play an important role for diabetics. “In particular, high intensity sweeteners have no impact on blood glucose and insulin levels, which means they can help those diagnosed with, or at risk of, type 2 diabetes avoid dangerous blood sugar spikes without having to completely give up sweet foods.

“Health organisations all over the world endorse replacing sugar with sweeteners to those with type 2 diabetes and we believe that reformulating food to reduce sugar content can play an important role in tackling the growing public health challenges linked to diabetes and obesity,”​ the nutrition expert argued argued.

Weighing the options

Like Karnik, Dr Simon Steenson, a nutrition scientist at the British Nutrition Foundation, suggested that low or no calorie sweeteners can play a role in weight management – as well as preventing issues like tooth decay.

“Substituting foods and drinks with sugar for those containing low or no calorie sweeteners may be a helpful way to reduce overall calorie intake, and assist with weight management, especially for people who have a taste preference for sweeter foods.”

weight loss fat obesity obese diet iStock nensuria
A multifaceted approach is needed to tackle obesity ©iStock/ nensuria

But he is also quick to stress there is no single silver bullet that can solve the problem of obesity. “There are many underlying causes of obesity, and the use of sweeteners will not solve the obesity crisis alone.

“It is important to remember that this is only one part of achieving a healthier, more balanced diet. Trying to cut down on other calorie-dense foods high in fat, such as crisps or fried foods, and being aware of the size of food portions that we eat, can also help us to avoid eating more calories than are needed. When it comes to staying a healthy weight, keeping active can also help with weight management, and has many other health benefits.”

Dr Steenson told FoodNavigator that the current state of public debate around sweeteners is not helpful for consumers, who are left confused by contradictory messages.

“There is often inconsistent and contradictory information in the media around the safety and health effects of low or no calorie sweeteners, which can cause confusion among consumers,”​ he observed.

But much of this mixed messaging stems from the fact that the science itself is currently inconclusive. On the one hand, the safety of low- and no-calorie sweeteners has clearly been established. But on the other there is some – albeit currently ‘weak’ – evidence that they could be associated with obesity, Dr Steenson explained.

“Scientific review of the safety of low- and no-calorie sweeteners used in food and drink products has shown that they are safe, including for children and pregnant women, and current average levels of intake are below the Acceptable Daily Intake (ADI) levels set by the European Food Safety Authority.

“Consumption of low- or no-calorie sweeteners has been linked to negative health effects, such as weight gain and type 2 diabetes. Although the evidence for these effects is weak at present, and may be complicated by confounders – for example, people who are already overweight may be more likely to choose diet drinks, rather than diet drinks themselves actually leading to weight gain.”

The answer, he suggested, is additional research that can shed light on a controversial topic. “Well-planned studies are needed to further investigate these associations, and it is important that the science on the long-term effects of low- or no-calorie sweeteners continues to be reviewed.”

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