Pooled across 143 randomised trials: body mass up 1.9 lb, fat-free mass up 1.8 lb, fat mass unchanged, body fat percentage down — with the studies essentially all agreeing. And the bloat everyone complains about traces to a loading phase that a 1996 study showed was never necessary.
The whole scare rests on one 2009 study of 20 rugby players that measured DHT and never looked at anyone's hair. The 56% rise it found moved men from 0.98 to 1.53 nmol/L — the normal range is 0.8 to 3.5. In 2025 a trial finally examined hair directly for 12 weeks and found no difference at all.
Same trial, same 59 people, same 40-gram dose: lactitol caused severe symptoms across the board and maltitol caused no laxative effect at all. Both are labelled sugar alcohols. Europe's regulator set a limit on erythritol for diarrhoea — not clots — and refused to drop the warning label. And the erythritol and xylitol heart scares came from one dataset.
The 2023 study linking erythritol to heart attacks came with a real mechanism — more reactive platelets, more clotting in animals. But the cohorts measured erythritol in blood, not diet, and your body makes its own: plasma levels track metabolic disease and fall after weight loss. Marker or cause is genuinely unresolved.
On the same day in July 2023, IARC called aspartame 'possibly carcinogenic' — a hazard statement, third of four levels — and JECFA reaffirmed the safe daily intake, noting a 70 kg adult would need 9–14 cans of diet drink a day to exceed it. The press ran the first report. WHO's own nutrition director said safety is not a major concern at normal doses.
Swapping sugary drinks for diet ones took off 2.3 lb across 17 randomised trials, and swapping for water did nothing. But the Framingham study found daily cola drinkers had 3.7% lower hip bone density — and diet cola looked the same, so switching does not buy you out of that one.
The WHO guideline covers 'all synthetic and naturally occurring' sweeteners and names stevia in the same list as aspartame — natural is written out as an exemption on purpose. And stevia has about a third the randomised trial evidence of aspartame, so the confidence people feel about it is not coming from a deeper evidence base.
The 2023 study behind 'sweetener damages DNA' is real, competently run and industry-free — and every experiment in it happened in a dish. Its own authors write that the health effects 'are not yet known'. That sentence did not make the coverage.
The WHO advises against non-sugar sweeteners — as a conditional recommendation, on evidence it grades low certainty, from a harm signal that is observational, in a document that names reverse causation itself. Meanwhile 17 randomised trials found swapping sugary drinks for sweetened ones took off 2.3 lb, while swapping for water did nothing.
Canning doesn't destroy the omega-3s — canned pink salmon carries more than a gram per 100 g. But albacore packed in oil holds 0.24 g against 0.86 g for the same fish in water, because the fat dissolves into the oil and the oil goes down the sink. Figures pulled from USDA FoodData Central, with the FDA/EPA mercury lists alongside.