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Is Diet drinks (Diet Coke, sugar-free) safe in pregnancy?
Generally safe
Yes — in moderation, with approved sweeteners.
What the evidence says
Diet drinks using UK-approved sweeteners (aspartame, sucralose, acesulfame K) are safe in moderation during pregnancy. Watch caffeine content if it contains cola — a can has about 40 mg of caffeine, which counts toward the daily 200 mg limit. Moderation also matters because high diet-drink intake is associated with cravings and less satisfying nutrition overall.
Why this matters
Approved sweeteners have been tested as safe. Caffeine content applies as with other caffeinated drinks.
Source:UK Food Standards Agency, NHS guidance
Last reviewed:April 2026
Please note — This is general guidance based on NHS advice as of April 2026. It is not medical advice. For advice on your specific pregnancy, please speak to your midwife or GP.
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