Which drinks raise blood sugar?
· 2 min
Drinks that carry carbohydrate are the group that raises blood sugar fastest; their form counts as much as their contents. Sugary carbonated drinks, fruit juices, and sweetened hot drinks belong here. Milk, too, comes with its own carbohydrate. Plain water, plain tea, and plain coffee carry none of that load.
The stomach makes the difference. A solid bite breaks down first, then passes into the intestine in small pieces; that takes a good while. Liquid skips the line; most of it leaves the stomach ahead of the solid, and carbohydrate reaching the intestine early is absorbed early. A study measuring stomach emptying speed found it closely tied to the rise’s peak.
The second difference is chewing. Chewing and swallowing a bite takes minutes; drinking the same energy takes seconds. Chewing stretches the time and triggers fullness signals; energy from liquid is thought not to produce that signal as strongly. The difference gathers in how fast the same carbohydrate gets in.
| Drink | Carbohydrate | Note |
|---|---|---|
| Water, plain mineral water | None | Global guidelines’ primary drink recommendation |
| Plain tea, plain coffee | None | Adding sugar or milk changes the picture |
| Sugary carbonated drink | High | Arrives unchewed and without fiber |
| Fruit juice | Present | The no-added-sugar kind counts here too |
| Milk, milk drinks | Present | Lactose is naturally present; fat and protein change the speed |
| Plant-based drink | Depends on the label | Plain and sweetened versions differ |
Does a drink go alone, or with the plate? That question changes the outcome. On its own, a sugary drink sends the curve up steeply, then down fast. Alongside a solid meal, the same drink’s total response stays below the sum of their separate responses, and the drop afterward softens. Responses to the same meal vary from person to person too. Same glass, different curve.
Caffeine is its own heading. Short-term studies giving pure caffeine found insulin sensitivity dropping in healthy people. Whole coffee didn’t give the same result; long-term observational data points a different way for coffee.
The morning drink on the table quietly grows the day’s total. The big cup on the bus, the bottle by the work desk, the second glass on the couch in the evening. None show on the plate, so none count. A glass at lunch break joins the same total.
Global guidelines treat water as the primary drink and suggest replacing sugary drinks with water or options carrying no energy. Reading a bottle’s label does as much work as reading the plate. Tracking liquid is usually easier, because drinks come in countable units.
Sources
- American Diabetes Association Professional Practice Committee. 5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2026. Diabetes Care. 2026;49(Suppl 1):S89-S131. doi:10.2337/dc26-S005
- World Health Organization. Guideline: Sugars Intake for Adults and Children. Geneva: World Health Organization; 2015. ISBN 978-92-4-154902-8.
- Xiang C, Sun Y, Luo Y, et al. Gastric emptying of a glucose drink is predictive of the glycaemic response to oral glucose and mixed meals, but unrelated to antecedent glycaemic control, in type 2 diabetes. Nutrition & Diabetes. 2024;14:13.
- Kim S, Song Y. Glycemic response to SSBs and ASBs: the role of mixed meals and individual variability. Nutrition Journal. 2025;24:113.
- Shi X, Xue W, Liang S, Zhao J, Zhang X. Acute caffeine ingestion reduces insulin sensitivity in healthy subjects: a systematic review and meta-analysis. Nutrition Journal. 2016;15:103.