The guide

Why meals make hills

By GyroscopeUpdated November 14, 202610 sources

Bread, rice, pasta and potatoes are starch, and starch is glucose linked in chains, so they raise blood sugar like sugar does. A cup of white rice makes a bigger hill than a can of cola. Protein, vegetables and fat on the same plate slow the hill down, and eating the carbs last made the peak about 46% lower in one trial.

Why does rice raise blood sugar more than soda?

Most people sort food into sweet and not sweet, and assume only the sweet side raises blood sugar. The bowl of rice with sushi or curry feels safe and the soda feels dangerous. People wearing a sensor are often shocked the first week, because the rice makes the bigger hill.

Starch is glucose molecules linked in long chains, like beads on a string. Your gut cuts the string and the beads go into your blood as glucose. A cup of cooked white rice has about 45 grams of carbs and less than 1 gram of fiber, so about 44 grams that end up as glucose. A 12-ounce can of cola has 39 grams of sugar. By glycemic load, which counts both how fast a food raises blood sugar and how much of it you eat, the rice comes out at about 32 and the cola at about 23.

None of that makes cola a better choice. The cola has nothing else in it, and each daily sugary drink went with 13% more type 2 diabetes over years, even after adjusting for bodyfat. It means the rice deserves the same respect.

What is the glycemic index?

The glycemic index (GI) ranks foods by how much a fixed amount of their carbs raises blood sugar, with pure glucose at 100. Low is 55 or less and high is 70 or more. Glycemic load (GL) adjusts for the portion. It’s GI times the grams of carbs you digest in a serving, divided by 100. GL is closer to what happens on your plate.

The international tables, compiled in 2008 from studies around the world, hold some surprises.

The authors of the table wrote that “the GI should not be used in isolation”. Ice cream and chocolate score low because of their fat, and fries beat a boiled potato for the same reason, which says nothing about what’s good for you. Use GI to pick between two versions of the same food, like rolled and instant oats, and use your sense for the rest. Test yourself in Which spikes more?

What makes a hill smaller?

Protein, vegetables and fat on the same plate. Fat lowers a food’s score, which is why fries come in under a boiled potato, and protein and vegetables eaten first lower the peak, as the next trial shows.

Eating the carbs last. In a 2019 trial, 15 adults with prediabetes ate the same meal three ways on three days. When they ate the protein and vegetables first and the carbs 10 minutes later, the peak was about 46% lower than when they ate the carbs first, and the total rise 39% lower. Same food, different order. It’s also why dessert after a full meal makes a smaller hill than the same sweet eaten alone.

Less milled grains. Grains you can still see, pasta and beans come apart slower than fine flour and puffed or flaked cereals.

A walk right after. Ten minutes of walking after each meal made the rise after eating 12% smaller than one 30-minute walk a day, and 22% smaller after dinner. See movement.

Try the plate yourself. Pick the carbs, then switch on carbs last, a walk or a short night.

White riceWhite toastRolled oatsInstant oatsBoiled potatoWhite spaghettiA can of cola

White rice, 1 cup cooked, with chicken and broccoli

Eat the carbs lastpeak more than 40% lowerWalk 10 minutes right afterafter-meal glucose 12% lower, 22% after dinnerShort night (5 hours)the hill grows

Available carbs

44 g

GI

73

Glycemic load

32

Carbs from USDA FoodData Central 168878 (Rice, white, long-grain, regular, enriched, cooked), 1 cup cooked. GI from the international tables (Atkinson 2008). Glycemic load is GI times available carbs over 100.

White rice makes a bigger hill than a can of cola: a load of 32 against 23. Starch is glucose in chains.

People differ. In 800 people eating the same meals, the hills came out very different (Zeevi 2015).

Photograph each meal and Gyroscope logs its carbs, fiber and sugar.

Why does the same meal spike me and not my friend?

People differ, a lot. In 2015, researchers in Israel tracked 800 people through 46,898 meals with sensors and found that identical meals gave very different responses from person to person. Blood tests, body measurements, activity and gut bacteria all helped predict who would respond how.

That’s the best use of a sensor for someone without diabetes, two weeks of comparing your own meals with each other. Comparing your numbers with someone else’s, or with a perfect flat line, says much less. Sensors also run high. In 15 healthy adults, a FreeStyle Libre 2 put a smoothie’s GI at 69 when fingertip blood said 53.

Are hills after meals bad?

A hill is your body doing its job. In 153 healthy people aged 7 to 80 wearing a sensor, the typical person spent about 30 minutes a day above 140 mg/dL and 96% of the day between 70 and 140. Nobody has run a trial showing that flattening normal hills helps people without diabetes. What predicts trouble is a high A1c and a high 2-hour number after the lab’s glucose drink. More on whether every spike is bad.

Do you need to cut carbs?

No. The ADA’s 2026 standards say there’s no ideal share of calories from carbs, protein or fat for preventing diabetes, and name both Mediterranean and low carb eating as options. The trial that cut new diabetes by 58% used a low-fat diet. Pick the pattern you can keep, cut the refined carbs and sweet drinks first, and keep fruit, beans and whole grains. More on cutting carbs and fruit.

meals.guide covers the plate itself, including how the order of your food changes a meal.