Sugar, Sweeteners, "Sugar-Free": The Honest Verdict

The science behind the sugar debate is remarkably sober: in the large review of randomised and cohort studies, more free sugars led to more weight and fewer to less — explainable through plain energy intake, not through a mystical metabolic injury. Sugar simply makes it exceptionally easy to over-consume energy: it sits concentrated in drinks (which barely satiate), in processed products (where nobody suspects it — coleslaw, ketchup, muesli), and it makes food tastier than satiety would like.

The WHO's guide value: free sugars below 10% of daily energy, better toward 5% — at 2,000 kcal, 10% is about 50 g, which half a litre of soda nearly delivers on its own. The most effective single step is therefore almost always the same: replace sugary drinks. Then comes a long gap, then the processed products, and only far behind them the spoon of honey in your tea.

Sweeteners (aspartame, sucralose, steviol glycosides & co.) are among the most intensively tested food ingredients of all — every authorised substance has a regulator-set acceptable daily intake (ADI) with a large safety margin that everyday consumption barely approaches. The systematic BMJ review of randomised trials found neither convincing evidence of relevant harm nor of clear health benefits.

Since 2023, the picture has become more differentiated. Two large cohorts delivered observational signals: in the UK Biobank, sweetener intake was associated with higher cardiovascular risk (largely mediated via type 2 diabetes), and in the French NutriNet-Santé cohort (~103,000 people, 9 years) with a 34 to 70 percent higher diabetes risk. Important for the honest reading: these are associations, not proven causes — people with weight or metabolic problems reach for "zero" more often, which can distort such statistics; the short-term randomised trials remain unremarkable. Then came the IARC classification of aspartame as "possibly carcinogenic" (group 2B) — which sounds more dramatic than it is: 2B describes limited evidence of a possible hazard (aloe vera sits in the same group), and the responsible risk-assessment body JECFA confirmed the acceptable daily intake unchanged. A chapter of their own are the sugar alcohols: for erythritol (2023, Nature Medicine) and xylitol (2024, European Heart Journal), cohort plus mechanistic data from the Cleveland Clinic group showed higher cardiovascular event rates at high blood levels and increased platelet clumping. Here too: observation plus lab work, no final proof — but reason enough to stop treating "sweetened with erythritol" as automatically the most harmless option.

None of this changes the order of priorities — it sharpens it: a sweetener remains the better choice than a sugary drink, and "less sweetness overall" remains the better choice than both.

The more interesting turn came from the WHO: its 2023 guideline advises against understanding sweeteners as a long-term instrument for weight control — not because of toxicity, but because the long-term evidence for weight benefit is weak. Translated: switching from cola to zero-sugar cola genuinely saves calories and makes sense as a bridge; the expectation that sweetener will solve the weight problem is not supported. The craving for sweetness itself remains trained — and that is the part you work on long term.

• "No added sugar" only means: no sugar added — date paste, juice concentrate or fruit purée still sweeten heavily and deliver the same free sugars.
• "Sugar-free" usually means: sweetened with sweeteners or sugar alcohols — the latter can act as laxatives in quantity (the mandatory notice is in the small print; details in the bar check), and for erythritol/xylitol there are additionally the cardiovascular warning signals described above.
• "With natural sweetness" is legally nothing and nutritionally not much either — coconut blossom sugar, agave syrup and honey are, to your body, essentially: sugar.
• The 10-second check beats every front label: ingredient list (where does sugar and its aliases appear — glucose syrup, dextrose, maltodextrin?) plus nutrition table ("of which sugars" per 100 g).

For training and weight, an unagitated priority list emerges: 1. Replace sugary drinks — with water, tea, coffee; via sweetener versions if you need the bridge. 2. Find the hidden sources: one look at the five most-eaten processed products of your week usually exposes two surprises. 3. Keep deliberate sweets: the slice of cake on Sunday is not a nutrition problem — the daily sweet drink consumed on the side was. Bans produce the rebound effect the comeback rule describes; structure beats harshness.

And the limit as always: for people with diabetes, the sugar and sweetener strategy belongs in the conversation with the treating practice — rules of thumb do not replace individual advice there.