Questions, answered.

Rapid-acting insulin analogues are not instant. They take time to start lowering glucose, so a bolus taken as you start eating can be running behind the carbohydrate. Research on bolus timing has consistently found that giving the mealtime dose ahead of eating produces a lower post-meal glucose peak than giving it at the start of the meal or after it, particularly at breakfast, and without increasing hypoglycaemia. Reviews of this evidence commonly reference a window of around 15 to 20 minutes for rapid-acting analogues.

That timing is not universal. It differs for faster-acting formulations such as Fiasp, for people using hybrid closed-loop systems, and for meals high in fat and protein where the carbohydrate absorbs more slowly. It also carries real risk in some situations: if your glucose is already low, if a restaurant meal might be delayed, or if you're not certain how much will actually be eaten. What timing suits you is a conversation for you and your diabetes team.

What Carbol does is remove the guesswork from the carb number, not the timing decision. Voice capture lets you describe a meal before it reaches the table, so if you and your team have decided pre-meal dosing suits you, you have an estimate in hand while there's still time.

• Get the whole plate in frame. Cropped-off food can't be counted.
• Shoot from directly above where you can, it reads portion size more accurately than an angled shot.
• Good light matters more than a good camera. Natural or bright indoor light beats a dim table.
• If the estimate comes back Low confidence, that's the app telling you it had to guess, check the number before you rely on it.

Whole plate in frame, shot from above, good light. This is the kind of photo that gets an accurate, high confidence estimate.

• Name each item separately rather than one vague description, e.g. "pad thai, medium bowl, with a spring roll on the side" rather than "some Thai food".
• Include size or quantity where you can, "medium bowl", "two slices", "a cup of rice".
• Voice is most useful before the food arrives, at a restaurant or while something's cooking, so your estimate is ready in time to act on it.
• If your connection drops, the recording queues and uploads on the next good connection, so it's fine to log while you're out of signal.

Example from restaurant menu: Medium 300g Scotch Fillet w peppercorn sauce, side of fries, onion rings and broccoli.

"Medium 300g scotch fillet with peppercorn sauce, a side of fries, onion rings, and broccoli."

Carbol runs as a Progressive Web App (PWA), so you add it to your home screen straight from your browser, no app store required.

iPhone (Safari)+−

• Open carbol.co.nz in Safari.
• Tap the Share icon at the bottom of the screen.
• Scroll down and tap "Add to Home Screen".
• Tap "Add" in the top right.

Android (Chrome)+−

• Open carbol.co.nz in Chrome.
• Tap the three-dot menu in the top right.
• Tap "Add to Home screen".
• Tap "Install app" to confirm.

Carbol now opens full-screen from your home screen, like any other app, with no browser bar.

A Progressive Web App is a website built to behave like a native app once it's added to your home screen: its own icon, full-screen launch with no browser bar, and it keeps working offline for anything already loaded. Carbol is built this way so you get the same experience as an app store download, without waiting on app store review for every update. Everything you can do in Carbol works the same whether you open it from the browser or from the home screen icon.