Many people are drinking less sugary soft drink than in the past. This is a great win for public health, given the recognised risks of diets high in sugar-sweetened drinks.

But over time, intake of diet soft drinks has grown. In fact, it’s so high that these products are now regularly detected in wastewater.

So what does the research say about how your health is affected in the long term if you drink them often?

What makes diet soft drinks sweet?

The World Health Organization (WHO) advises people “reduce their daily intake of free sugars to less than 10% of their total energy intake. A further reduction to below 5% or roughly 25 grams (six teaspoons) per day would provide additional health benefits.”

But most regular soft drinks contain a lot of sugar. A regular 335 millilitre can of original Coca-Cola contains at least seven teaspoons of added sugar.

Diet soft drinks are designed to taste similar to regular soft drinks but without the sugar. Instead of sugar, diet soft drinks contain artificial or natural sweeteners. The artificial sweeteners include aspartame, saccharin and sucralose. The natural sweeteners include stevia and monk fruit extract, which come from plant sources.

Many artificial sweeteners are much sweeter than sugar so less is needed to provide the same burst of sweetness.

Diet soft drinks are marketed as healthier alternatives to regular soft drinks, particularly for people who want to reduce their sugar intake or manage their weight.

But while surveys of Australian adults and adolescents show most people understand the benefits of reducing their sugar intake, they often aren’t as aware about how diet drinks may affect health more broadly.

What does the research say about aspartame?

The artificial sweeteners in soft drinks are considered safe for consumption by food authorities, including in the US and Australia. However, some researchers have raised concern about the long-term risks of consumption.

People who drink diet soft drinks regularly and often are more likely to develop certain metabolic conditions (such as diabetes and heart disease) than those who don’t drink diet soft drinks.

The link was found even after accounting for other dietary and lifestyle factors (such as physical activity).

In 2023, the WHO announced reports had found aspartame – the main sweetener used in diet soft drinks – was “possibly carcinogenic to humans” (carcinogenic means cancer-causing).

Importantly though, the report noted there is not enough current scientific evidence to be truly confident aspartame may increase the risk of cancer and emphasised it’s safe to consume occasionally.

Will diet soft drinks help manage weight?

Despite the word “diet” in the name, diet soft drinks are not strongly linked with weight management.

In 2022, the WHO conducted a systematic review (where researchers look at all available evidence on a topic) on whether the use of artificial sweeteners is beneficial for weight management.

Overall, the randomised controlled trials they looked at suggested slightly more weight loss in people who used artificial sweeteners.

But the observational studies (where no intervention occurs and participants are monitored over time) found people who consume high amounts of artificial sweeteners tended to have an increased risk of higher body mass index and a 76% increased likelihood of having obesity.

In other words, artificial sweeteners may not directly help manage weight over the long term. This resulted in the WHO advising artificial sweeteners should not be used to manage weight.

Studies in animals have suggested consuming high levels of artificial sweeteners can signal to the brain it is being starved of fuel, which can lead to more eating. However, the evidence for this happening in humans is still unproven.

What about inflammation and dental issues?

There is some early evidence artificial sweeteners may irritate the lining of the digestive system, causing inflammation and increasing the likelihood of diarrhoea, constipation, bloating and other symptoms often associated with irritable bowel syndrome. However, this study noted more research is needed.

High amounts of diet soft drinks have also been linked with liver disease, which is based on inflammation.

The consumption of diet soft drinks is also associated with dental erosion.

Many soft drinks contain phosphoric and citric acid, which can damage your tooth enamel and contribute to dental erosion.

Moderation is key

As with many aspects of nutrition, moderation is key with diet soft drinks.

Drinking diet soft drinks occasionally is unlikely to harm your health, but frequent or excessive intake may increase health risks in the longer term.

Plain water, infused water, sparkling water, herbal teas or milks remain the best options for hydration.

Lauren Ball, Professor of Community Health and Wellbeing, The University of Queensland and Emily Burch, Accredited Practising Dietitian and Lecturer, Southern Cross University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The weight-loss drug Wegovy is now available in Australia.

Wegovy is administered as a once-weekly injection and is approved specifically for weight management. It’s intended to be used in combination with a reduced-energy diet and increased physical activity.

So how does Wegovy work and how much weight can you expect to lose while taking it? And what are the potential risks – and costs – for those who use it?

Let’s look at what the science says.

What is Wegovy?

Wegovy is a brand name for the medication semaglutide. Semaglutide is a glucagon-like peptide-1 receptor agonist (GLP-1RA). This means it makes your body’s own glucagon-like peptide-1 hormone, called GLP-1 for short, work better.

Normally when you eat, the body releases the GLP-1 hormone which helps signal to your brain that you are full. Semaglutides enhance this effect, leading to a feeling of fullness, even when you haven’t eaten.

Another role of GLP-1 is to stimulate the body to produce more insulin, a hormone which helps lower the level of glucose (sugar) in the blood. That’s why semaglutides have been used for several years to treat type 2 diabetes.

How does Wegovy differ from Ozempic?

Like Wegovy, Ozempic is a semaglutide. The way Wegovy and Ozempic work in the body are essentially the same. They’re made by the same pharmaceutical company, Novo Nordisk.

But there are two differences:

1) They are approved for two different (but related) reasons.

In Australia (and the United States), Ozempic is approved for use to improve blood glucose levels in adults with type 2 diabetes. By managing blood glucose levels effectively, the medication aims to reduce the risk of major complications, such as heart disease.

Wegovy is approved for use alongside diet and exercise for people with a body mass index (BMI) of 30 or greater, or 27 or greater but with other conditions such as high blood pressure.

Wegovy can also be used in people aged 12 years and older. Like Ozempic, Wegovy aims to reduce the risk of future health complications, including heart disease.

2) They are both injected but come in different strengths.

Ozempic is available in pre-loaded single-dose pens with varying dosages of 0.25 mg, 0.5 mg, 1 mg, or 2 mg per injection. The dose can be slowly increased, up to a maximum of 2 mg per week, if needed.

Wegovy is available in prefilled single-dose pens with doses of 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, or 2.4 mg. The treatment starts with a dose of 0.25 mg once weekly for four weeks, after which the dose is gradually increased until reaching a maintenance dose of 2.4 mg weekly.

While it’s unknown what the impact of Wegovy’s introduction will be on Ozempic’s availability, Ozempic is still anticipated to be in low supply for the remainder of 2024.

Is Wegovy effective for weight loss?

Given Wegovy is a semaglutide, there is very strong evidence it can help people lose weight and maintain this weight loss.

A recent study found that over four years, participants taking Wevovy as indicated experienced an average weight loss of 10.2% body weight and a reduction in waist circumference of 7.7cm.

For those who stop taking the medication, analyses have shown that about two-thirds of weight lost is regained.

What are the side effects of Wegovy?

The most common side effects are nausea and vomiting.

However, other serious side effects are also possible because of the whole-of-body impact of the medication. Thyroid tumours and cancer have been detected as a risk in animal studies, yet are rarely seen in human scientific literature.

In the four-year Wegovy trial, 16.6% of participants who received Wegovy (1,461 people) experienced an adverse event that led to them permanently discontinuing their use of the medication. This was higher than the 8.2% of participants (718 people) who received the placebo (with no active ingredient).

Side effects included gastrointestinal disorders (including nausea and vomiting), which affected 10% of people who used Wegovy compared to 2% of people who used the placebo.

Gallbladder-related disorders occurred in 2.8% of people who used Wegovy, and 2.3% of people who received the placebo.

Recently, concerns about suicidal thoughts and behaviours have been raised, after a global analysis reviewed more than 36 million reports of adverse events from semaglutide (Ozempic or Wegovy) since 2000.

There were 107 reports of suicidal thoughts and self-harm among people taking semaglutide, sadly including six actual deaths. When people stopped the medication, 62.5% found the thoughts went away. What we don’t know is whether dose, weight loss, or previous mental health status or use of antidepressants had a role to play.

Finally, concerns are growing about the negative effect of semaglutides on our social and emotional connection with food. Anecdotal and scientific evidence suggests people who use semaglutides significantly reduce their daily dietary intake (as anticipated) by skipping meals and avoiding social occasions – not very enjoyable for people and their loved ones.

How can people access Wegovy?

Wegovy is available for purchase at pharmacists with a prescription from a doctor.

But there is a hefty price tag. Wegovy is not currently subsidised through the Pharmaceutical Benefits Scheme, leaving patients to cover the cost. The current cost is estimated at around A$460 per month dose.

If you’re considering Wegovy, make an appointment with your doctor for individual advice.

Lauren Ball, Professor of Community Health and Wellbeing, The University of Queensland and Emily Burch, Accredited Practising Dietitian and Lecturer, Southern Cross University

This article is republished from The Conversation under a Creative Commons license. Read the original article.