Grocery store, Tuesday night.

I was standing in the snack aisle with a protein bar in each hand, reading the backs of the wrappers like a man cramming for a test.

My wife found me there ten minutes later.

She asked if I was okay. I told her I was counting sugars. Plural.

All week, we tested protein bars with my glucose monitor, the small sensor on my arm that checks my blood sugar every few minutes. And the bar that said "low sugar" on the front raised my blood sugar far more than I expected.

The sugar was in there. It just went by other names.

So today is about those names.

By the way, the timing is interesting. Since January 1, Canada has required a warning symbol on the front of packaged foods that are high in sugar, salt, or saturated fat. Here in the US, the FDA proposed its own front-of-box label back in January 2025. It's a small box that rates added sugars as low, medium, or high.

But as of this summer, the FDA still hadn't made that rule final.

In other words, for now, the ingredient list on the back of the box is the only place the full truth lives. Here's how to read it.

Which Everyday Drink Leaves a Mineral Behind?

Here the measurement is not glucose, but the question has the same shape: one ordinary drink, and what it does to you over years.

Scientists at prestigious universities have linked a common drink to skyrocketing rates of Alzheimer’s disease. It carries shocking levels of a toxic mineral present in many patients’ brains, and that mineral builds in the brain over time — killing off a molecule that keeps your memories intact.

Five candidates. Pick one before you read on:

▸ Black Coffee (Colombian Beans)

▸ White Wine (Chardonnay Grapes)

▸ Diet Soda

▸ Tap Water

▸ Beer

If you think it’s the drinks that contain alcohol, you might want to think again.

● This Week's Rules

📌 This Week's Rules

✓	Read the sweetener, not just the sugar line. A bar can say 0g sugar and still use maltitol, which raises blood sugar about half as much as table sugar.

✓	Ingredients are listed by weight, heaviest first. When sugar is split into three different names, each one slides further down the list.

✓	Words that end in "-ose" are sugars: dextrose, maltose, sucrose, fructose.

✓	Any syrup is sugar. Brown rice syrup, tapioca syrup, and corn syrup solids all count.

✓	Maltodextrin isn't counted as sugar on the label. It still raises blood sugar like one.

✓	Not sure about a bar? A handful of nuts has no hidden names at all.

● The Scoreboard

Here's every bar from this week, ranked by how much each one raised my blood sugar. At the bottom is the plain handful of almonds from Thursday's test.

🍫 Crispy bar with brown rice syrup

+68

🌴 Date-and-nut "clean" bar

+55

🏷️ "Low sugar" bar with maltitol

+44

💪 High-fiber bar with erythritol

+16

🥜 A handful of almonds

mg/dL rise above fasting, measured on my glucose monitor (Libre 3). This is one person's experiment, not medical advice. Everyone's body responds differently.

The worst bar wasn't the one with the most sugar printed on the label.

It was the crispy bar made with brown rice syrup. The University of Sydney's glycemic index database puts rice syrup at 98. Table sugar sits around 65. In other words, rice syrup raises blood sugar almost as fast as pure glucose.

Then there was Monday's "low sugar" bar. That bar was sweetened with maltitol, and it raised my blood sugar about 44 points.

The label said 0g sugar. My glucose monitor disagreed.

Meanwhile, the high-fiber bar sweetened with erythritol raised my blood sugar just 16 points. And the almonds? About 6.

I don't know if your body would rank these bars in the same order. People vary a lot. But one thing was clear to me by Thursday... the words on the front of the wrapper told me almost nothing about how much the bar would raise my blood sugar.

● Reader Mail

Question

My protein bar says "no added sugar," but dates are the first ingredient. Is that a trick?

My Response

Not a trick, but not the whole story either. Dates are fruit, so they often aren't counted the same way as added sugar on the label. My glucose monitor doesn't care about that difference. The date-and-nut bar this week raised my blood sugar about 55 points. The nuts and fiber in that bar help some. If you love date bars, try eating one right after a meal instead of on an empty stomach.

Question

What is a sugar alcohol? Do they all work the same way?

My Response

No, and this was the biggest surprise of my week. Sugar alcohols are sweeteners your body only partly absorbs. Erythritol has a glycemic index close to zero, because your body passes it out without turning it into glucose. Maltitol is different. Its glycemic index is around 35, roughly half of table sugar. In other words, a bar full of maltitol can say 0g sugar and still raise your blood sugar. Maltitol can also upset some people's stomachs, so go slow with it.

Question

Won't the new labels on the front of the box fix all this?

My Response

Maybe, someday. The FDA's proposed box would rate added sugars as low, medium, or high right on the front of the package. But the rule isn't final yet, and big food companies would get three years to add the box once it is. And here's the thing... maltitol and maltodextrin aren't counted as added sugars. So even with the new box, a bar full of either one could still look fine from the front. The ingredient list on the back will still matter.

● Next Week: The Yogurt Aisle

Next week, I'm taking my glucose monitor to the yogurt aisle.

🔬

Mon

Fruit-on-the-bottom yogurt on trial

🛠

Tue

Build a yogurt bowl that keeps blood sugar steady

🧠

Wed

Greek vs Activia vs fruit yogurt

🔄

Thu

Flavored yogurt vs plain Greek with berries

I have a feeling the fruit on the bottom has a few other names of its own...

Stay steady

Which Everyday Drink Leaves a Mineral Behind?

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