Pop quiz.

Three breakfasts. One glucose monitor. Guess which one raised my blood sugar the most.

A bowl of instant oatmeal with a drizzle of honey. A bowl of cornflakes with milk. A slice of whole wheat toast with mashed avocado.

Most people guess the cereal. Some guess the oatmeal, because honey feels sneaky. Almost nobody guesses right for the reason they think.

I ate all three on different mornings. Same portion. Same fasting start. My glucose monitor recorded the rest.

Take a guess. Then scroll down.

● The Reveal

The cereal won.

Not by a little. The cornflakes and milk raised my blood sugar higher than either of the other two.

Here's the thing. Cornflakes sit around 81 on the glycemic index, close to pure glucose. In other words, my body treated that bowl almost like drinking sugar water.

A report out this summer found that European cereal makers have cut added sugar in their products by nearly a fifth over the past decade. That's real progress.

But cutting sugar doesn't fix the bigger problem. Corn flakes are so processed, so finely flattened, that your body barely has to work to break them down. The starch turns to sugar almost instantly. Less sugar in the box doesn't change that.

The oatmeal came in second, up 58 points. The honey pushed it higher than plain oats would go. So did the instant kind, since finely milled oats break down faster than the steel-cut kind.

And the avocado toast, up just 42 points. The fat and fiber in avocado slow down how fast your body absorbs the bread's carbs. It's still bread, though. It still raised my blood sugar more than a food with no starch at all would.

This is one person's experiment, not medical advice. Everyone's body responds differently.

● The Scoreboard

So what works here?

Skip the cornflakes. Or if you love them, add protein next to the bowl. A few eggs or a spoonful of Greek yogurt can blunt a chunk of the rise.

Swap instant oats for the steel-cut kind. And save the honey for a bowl that already has some protein sitting in it.

The avocado toast? Already your best move here. Swap the white bread for a whole grain or sourdough loaf and it gets even steadier.

Same three breakfasts. Completely different mornings, once you know which one is doing the damage.

Stay steady