Quick answer: Are artificial sweeteners worse than sugar? Probably not consistently worse — but they are also not the free pass the marketing suggests. The 2023 World Health Organization (WHO) guideline on non-sugar sweeteners reviewed more than 280 studies and concluded they offer no long-term benefit for body-fat reduction, while higher intake was linked to higher rates of type 2 diabetes, cardiovascular events, and all-cause mortality. The honest answer is to reduce overall added-sugar intake rather than swap one sweetener for another.
The diet soda was supposed to settle the question. Zero calories, no sugar spike, all of the sweetness without the metabolic cost — for forty years that was the implicit promise on the can. Then the long-term data started arriving, and it did not say what the marketing said. Cohort studies linked daily diet-drink consumption to higher rates of stroke and metabolic disease. A 2023 Cleveland Clinic trial tied one popular replacement sweetener to a near-doubled risk of major cardiac events. None of this makes sugar suddenly fine. It does mean the binary most labels offer — sugar or artificial — is not a choice between a bad option and a good one.
What the World Health Organization actually concluded
In May 2023, the World Health Organization (WHO) issued a formal guideline recommending against the use of non-sugar sweeteners for weight control. The guidance applies to the whole category — aspartame, sucralose, acesulfame potassium, saccharin, stevia, and stevia derivatives — and was based on a systematic review of more than 280 studies.
The review found two seemingly contradictory things. In short-term randomized trials, people who replaced sugar with non-sugar sweeteners consumed slightly fewer calories and lost about 0.71 kilograms on average. But in long-term cohort studies, higher intake was associated with a 76 percent higher risk of obesity, a 23 percent higher risk of type 2 diabetes, a 19 percent higher risk of stroke, and a 12 percent higher rate of all-cause mortality. The WHO weighted the long-term signal more heavily, concluding the trade-off did not favor sustained use. Cohort data cannot prove causation, but it does remove the central reason most people reach for these sweeteners in the first place.
The Cleveland Clinic erythritol study, in context
Around the same window, a research team led by Dr. Stanley Hazen at the Cleveland Clinic published a paper in Nature Medicine that drew its own headlines. The study followed three groups of cardiac patients — more than 4,000 people in total — across the United States and Europe. After three years, participants in the highest blood-erythritol quartile had roughly twice the rate of major cardiovascular events (heart attack, stroke, or death) compared with those in the lowest quartile. Follow-up laboratory experiments suggested a plausible mechanism: erythritol appeared to make platelets more reactive, increasing the tendency to form clots.
Erythritol is technically a sugar alcohol, but it is folded into this conversation because it is the most common bulk replacement in "sugar-free" and "keto" products. Occasional exposure is not the same as routine daily intake — but for regular consumers of erythritol-sweetened drinks and snacks, the signal is worth taking seriously.
Sugar is not the safe alternative either
None of this rehabilitates added sugar. The American Heart Association (AHA) recommends a daily limit of about 24 grams for adult women and 36 grams for adult men. The average United States adult consumes around 68 grams per day — two to three times those limits. At that level, the cardiovascular, metabolic, and dental harms of excess sugar are well established.
The framing problem is treating sugar and artificial sweeteners as the only two choices. The shared answer to both is to reduce the overall sweetness load of the diet, not to find a "safer" way to keep it the same. Whole-food sweetness from fruit does not produce the same risk associations in the cohort data above.
Sweetener categories at a glance
Approximate properties of common sweeteners. Glycemic index values are rounded. The right column captures the strongest signal from recent peer-reviewed literature, not a final verdict.
| Sweetener | Type | Glycemic index (approx.) | Key signal in recent research |
|---|---|---|---|
| Refined cane sugar | Sucrose | 65 | Cardiometabolic harm at high intake; most adults exceed AHA limits |
| Honey (raw) | Fructose-glucose blend | 50–60 | Trace polyphenols; still added sugar |
| Maple syrup | Sucrose + minerals | 54 | Trace manganese and zinc; calorie-equivalent to sugar |
| Coconut sugar | Sucrose + inulin | 35–54 | Lower glycemic load; minimally processed |
| Stevia | Plant-derived | 0 | Included in 2023 WHO guidance against use for weight control |
| Erythritol | Sugar alcohol | 0 | 2023 Cleveland Clinic: top blood-level quartile ~2x major cardiovascular events |
| Aspartame | Artificial dipeptide | 0 | 2023 IARC classification: "possibly carcinogenic" (Group 2B); acceptable daily intake unchanged |
| Sucralose | Artificial chlorinated | 0 | Trials show gut microbiome shifts and altered glucose response at high intake |
A practical framework that does not require picking a side
A few principles hold up across the literature. First, the total sweetness in the diet matters more than the particular sweetener. Second, whole-food sweetness — a piece of fruit, a square of high-cacao chocolate — tends to come with fiber, polyphenols, or protein that change how the body handles the sugar. Third, minimally processed natural sweeteners carry a real caloric and glycemic cost but do not show the same long-term cohort signals as high non-sugar sweetener intake.
At Marmels we sweeten with organic coconut sugar — about 12 grams per 60-gram bar, inside the American Heart Association daily limits. We do not use sugar alcohols, artificial sweeteners, or sugar substitutes of any kind. The aim is sweetness you can recognize, not engineer around.
Frequently Asked Questions
Are artificial sweeteners worse than sugar for weight loss?
The 2023 World Health Organization (WHO) guideline concluded that non-sugar sweeteners offer no long-term benefit for body-fat reduction in adults or children. Short-term trials show small calorie reductions, but multi-year cohort studies show higher body mass index and obesity rates among regular consumers. The WHO reading is that the trade-off does not favor sustained use for weight management.
What did the 2023 WHO guideline say about non-sugar sweeteners?
The World Health Organization advised against using non-sugar sweeteners — aspartame, sucralose, stevia, saccharin, and acesulfame potassium — as a means of weight control or chronic disease prevention. The guidance cited associations with higher rates of type 2 diabetes, stroke, and all-cause mortality at higher intake levels. The recommendation is conditional, meaning further research could refine it.
Is erythritol bad for your heart?
A 2023 Cleveland Clinic study in Nature Medicine found that patients in the highest blood-erythritol quartile had roughly twice the rate of major cardiovascular events over three years versus the lowest, with a plausible mechanism involving platelet activation. The finding is observational and reflects high intake. Occasional exposure is unlikely to drive risk, but routine daily use of erythritol-sweetened products is the situation the study flagged.
What is the healthiest sugar substitute?
No single sweetener emerges as a clear winner. Among added sweeteners, the minimally processed natural options — raw honey, pure maple syrup, organic coconut sugar — show fewer concerning long-term associations than high-intensity non-sugar sweeteners or sugar alcohols. They still carry calories and a glycemic impact, so portion matters. Whole-food sweetness from fruit is the most robustly supported source.
Does aspartame cause cancer?
In 2023 the International Agency for Research on Cancer (IARC) classified aspartame as "possibly carcinogenic to humans" (Group 2B) based on limited evidence in humans. The same week, the WHO's Joint Expert Committee on Food Additives reaffirmed the acceptable daily intake of 40 milligrams per kilogram of body weight, about 14 cans of diet soda for a 70-kilogram adult. The two bodies use different frameworks: hazard identification versus risk at typical exposure.
How much added sugar can I have in a day?
The American Heart Association sets daily added-sugar limits of about 24 grams for adult women and 36 grams for adult men. The average United States adult consumes roughly 68 grams per day, more than twice those limits. A practical anchor: keep added sugar from any single snack in the 6 to 12 gram range and weight the rest of the diet toward unsweetened or naturally sweet whole foods.
There is no answer that fits on a label. Less sweet over time — with whatever sweetener you choose — is the part of the question that actually has evidence behind it. For how we think about ingredients and sourcing, see our science page.
