How diet drinks are ‘STOPPING you lose weight – and ruining your diet’
WHEN Diet Coke hit the shelves nearly 40 years ago, it quickly became the world's most popular low-calorie drink.
And with drinks manufacturers promising the same great taste of Coke without the calories it's hardly a surprise.
But in recent years, scientists have started to question whether the beverage - and other similar diet drinks - are entirely harmless.
It's true, Diet Coke does contain just ONE calorie, making it a much better alternative than it "full-fat" cousin Coke, which packs 139 calories per 330ml can.
And when it comes to sugar levels, there's no comparison either.
Diet Coke has none, while one can of regular Coke adds a whopping 35g of sugar - the equivalent of seven teaspoons - to your daily diet.
But the jury remains out on whether the artificial sweeteners - used to give Diet Coke its taste - are harm-free.
More harmful than harm-free?
In recent years, the scientific microscope has firmly focused on sugar and links with obesity, heart disease and diabetes.
And a study published last month even claims that guzzling Diet Coke could make you put weight on.
Experts in Australia say that's because people who drink it don't necessarily reduce their overall sugar intake.
Professor Peter Clifton, who led the research, said: ";Consumers of artificial sweeteners do not reduce their overall intake of sugar.
"They use both sugar and low-calorie sweeteners and may psychologically feel they can indulge in their favourite foods.
"Artificial sweeteners can also change the gut bacteria which may lead to weight gain and risk of type 2 diabetes".
Why are artificial sweeteners calorie-free?
Low calorie sweeteners are used in place of sucrose, glucose and fructose and have an intense sweet flavour without the calories.
Also called non-nutritive sweeteners, these can be synthetic – such as saccharin and aspartame – or naturally derived, such as steviol, which comes from the Stevia plant.
Eunice Zhang, a clinical instructor at the University of California, told : "The key to these virtually calorie-free sweeteners is that they are not broken down during digestion into natural sugars like glucose, fructose and galactose, which are then either used for energy or converted into fat.
Do you really know which can of pop is better for you?
MOST nutritionists will tell you to reach for a glass of water.
But if you really must quench your thirst with a fizzy drink, you need to know the difference between sugar and the artificial sweetener aspartme.
Sugar
Sugar is a natural ingredient that is cultivated from sugar cane.
They are carbohydrates that provide energy for the body and its most common form is glucose.
Some are also found naturally in foods like fruit, vegetables and milk.
The body does not distinguish between the different types of sugar and breaks them down in exactly the same way.
But just because it is naturally occurring doesn't mean it is without health risks.
Too much sugar can lead to obesity, type 2 diabetes, some cancers and an increased risk of heart attack and stroke.
Aspartme
Aspartme is an artificial sweetener used instead of sugar to make food taste sweeter.
It is low in calories and up to 200 times sweeter than sugar.
Aspartame is used all over the world as a sugar substitute in thousands of foods and drinks, including cereals, sugar-free chewing gum, low-calorie soft drinks and table-top sweeteners, according to the NHS.
But it has been subject to more scare stories than any other sweetener.
There have been reports it is linked to an increased chance of brain tumours, cancer, premature birth, liver damage and allergies.
However the European Food Safety Authority conducted a comprehensive review into the evidence in 2013 and concluded it was safe for human consumption.
"Non-nutritive sweeteners have different byproducts that are not converted into calories.
"Aspartame, for example, undergoes a different metabolic process that doesn’t yield simple sugars.
"Others such as saccharin and sucralose are not broken down at all, but instead are absorbed directly into the bloodstream and excreted in the urine."
She said that theoretically, that means that they are a better choice for those with diabetes.
Gut-altering
However, there is growing evidence over the last decade that these sweeteners can alter healthy metabolic processes in other ways, specifically in the gut.
Dr Zhang added: "Long-term use of these sweeteners has been associated with a higher risk of Type 2 diabetes.
"Sweeteners, such as saccharin, have been shown to change the type and function of the gut microbiome, the community of microorganisms that live in the intestine.
"Aspartame decreases the activity of a gut enzyme that is normally protective against Type 2 diabetes.
"Furthermore, this response may be exacerbated by the 'mismatch' between the body perceiving something as tasting sweet and the expected associated calories.
"The greater the discrepancy between the sweetness and actual caloric content, the greater the metabolic dysregulation."
Weight gain risk
Previous studies have also found links between calorie-free drinks, such as Diet Coke, and weight gain.
Scientists at Massachusetts General Hospital have found the breakdown product in the drink's sweetener - aspartame - disrupts the metabolic rate.
Dr Richard Hodin, the study's senior author, said: "Sugar substitutes like aspartame are designed to promote weight loss and decrease the incidence of metabolic syndrome.
"But a number of clinical and epidemiologic studies have suggested that these products don't work very well and may actually make things worse.
"We found that aspartame blocks a gut enzyme called intestinal alkaline phosphatase (IAP) that we previously showed can prevent obesity, diabetes and metabolic syndrome.
"So we think that aspartame might not work because, even as it is substituting for sugar, it blocks the beneficial aspects of IAP."
MORE ON DIET
However, campaigners say that low-calorie drinks are a safer alternative to help people reduce sugar consumption in their diet.
British Soft Drinks Association Director General Gavin Partington said: “The increased use of non-sugar sweeteners in soft drinks, has led to a drastic reduction in sugar intake from soft drinks, down by 31.3% between 2015 and 2019, according to Kantar Worldpanel data.
"In March 2017, the UK Government and Public Health England publicly endorsed the use of low-and no-calorie sweeteners as a safe alternative to reduce sugar in food and drink and help people manage their weight.”