Briefing: The Current State of Artificial Sweeteners
This briefing summarises the key findings regarding artificial sweeteners (also known as non-nutritive sweeteners) from the provided research excerpts. It addresses common concerns and presents the current scientific consensus, particularly drawing on evidence from randomised controlled trials.

Main Themes and Key Insights:
1. Re-evaluation of Chronic Disease Risk and Mortality:

Initial Concerns: Historically, artificial sweeteners have been linked in observational research to an increased risk of chronic diseases such as obesity, diabetes, and cardiovascular disease, and even all-cause mortality.
Reverse Causation as a Confounding Factor: The current understanding suggests that these observational links are likely a case of "reverse causation." Individuals already suffering from these conditions are more prone to consume artificial sweeteners as a sugar replacement, thus "skewing the association."
Randomised Controlled Trials (RCTs) Show No Detriment: RCTs, which are better designed to establish causality, "generally show little-to-no detriment."
A 2022 meta-analysis by McGlynn et al., involving 17 RCTs, found that artificial sweeteners, when compared to sugar-sweetened beverages, led to "reduced bodyweight, BMI, bodyfat percentage, and liver fat." Crucially, no negative impact was observed on "metabolic health, cardiovascular health markers such as blood pressure or lipid profiles, or mortality risk."
Similarly, a 2020 review by Pang et al. concluded that artificial sweeteners "appear to have a neutral-to-beneficial effect on bodyweight and glycemic control in the long run."
2. Impact on Food Cravings and Appetite:

Hypothesis: The common theory is that the sweet taste without calories from artificial sweeteners increases hunger and cravings, leading to greater calorie intake.
RCTs Contradict Hypothesis: While some acute studies suggest a potential mechanistic increase in hunger, meta-analyses of RCTs "still typically find that artificial sweetener consumption tends to result in similar or decreased calorie consumption, not increased."
3. Effects on the Gut Microbiome:

Early Stages of Research: This is a "relatively new area of research," and human studies are "in its infancy, with limited research available."
Limited Evidence of Negative Impact: A recent study by Thomson et al. investigating the effects of a very high dose of sucralose (780mg/day, equivalent to 15-25 diet sodas) over seven days found "no evidence of sucralose consumption causing alterations in the gut microbiome."
4. Comparison to Sugar-Sweetened Beverages (SSBs) vs. Water:

Preferable to SSBs: The evidence strongly suggests that "replacing traditional, sugar-sweetened beverages/foods with artificially sweetened beverages/foods will likely have a neutral-to-beneficial effect on your overall health."
Comparison to Water – Generally Similar Outcomes: The McGlynn et al. meta-analysis also compared artificially sweetened beverages to water.
Substituting water with artificially sweetened beverages resulted in "no significant weight change, no meaningful changes in BMI, bodyfat, or liver fat."
Caveats: "An uncertain, small negative effect on HbA1C was noted (+0.21%, 95% CI 0.02%–0.40%), and a small, positive effect on systolic blood pressure was noted (–2.63 mmHg, 95% CI –4.71 to –0.55 mmHg)." However, these "should be viewed cautiously" due to the low number of studies.
5. Important Caveat – Variety of Sweeteners:

Not All Sweeteners are Equal: The research highlights that "while we lump sweeteners together as being 'artificial' or 'non-nutritive,' there are many types of sweetener."
Lack of Definitive Answers: It's crucial to acknowledge that "we cannot necessarily assume that they are all equivalent in their effects on health. To be clear, until more evidence is available on different types of sweeteners, a definitive answer cannot be provided."
Overall Conclusion and Recommendation:
Based on the available randomised controlled trial research, the evidence suggests that "artificial sweeteners are neither harmful nor beneficial."

When used as a replacement for sugar-sweetened foods and drinks, they "appear to have neutral to beneficial effects on body weight, glycemic control, and cardiovascular risk factors."
Concerns regarding cravings, the gut microbiome, and long-term health risks have largely "not been substantiated in randomised controlled trials," with observational associations often being confounded by reverse causation.
Even when directly compared to water, artificially sweetened beverages generally lead to "clinically similar outcomes."
Therefore, the conclusion is that "unless you’re personally intolerant or simply prefer to avoid them, there’s no strong scientific reason to cut artificial sweeteners from your diet. And for many people, they can be a practical tool for supporting dietary adherence and long-term health goals."