Tipo 00 flour is a highly refined white flour, and nutritionally it behaves like one. It has a glycemic index around 85, which is high enough to cause a rapid spike in blood sugar after eating. It contains little fiber, is stripped of most of the bran and germ where vitamins and minerals concentrate, and often lacks the fortification that many other white flours carry. That said, 00 flour isn’t uniquely unhealthy compared to other refined flours. Its reputation comes from what it does in the kitchen, not from any nutritional advantage or disadvantage.
What Makes 00 Flour Different
The “00” refers to how finely the flour is milled, not to its protein or nutrient content. It’s the finest grind in the Italian flour classification system. This ultra-fine texture creates a smooth, elastic dough prized for Neapolitan pizza and fresh pasta. Protein content in 00 flour typically ranges between 8% and 12%, which overlaps with both cake flour (on the low end) and bread flour (on the high end), depending on the wheat variety and brand.
Because it’s so finely milled, 00 flour produces a tender, less chewy result than coarser flours. But that fine particle size is also what drives its high glycemic response. Smaller particles are broken down faster during digestion, which means glucose enters the bloodstream more quickly.
Blood Sugar and Insulin Effects
With a glycemic index of roughly 85, 00 flour sits in the high-glycemic category. For comparison, kamut flour (an ancient grain alternative sometimes used in pizza dough) has a glycemic index around 45. Pure glucose, the reference point for the scale, scores 100.
Research published in The American Journal of Clinical Nutrition found that people who habitually ate refined-grain flour products had higher fasting insulin levels than those who ate whole-grain products. In a controlled trial, fasting insulin was 10% lower during a whole-grain diet compared to a refined-grain diet. High circulating insulin over time is linked to insulin resistance, weight gain, and increased risk of type 2 diabetes. The blood sugar spike from 00 flour isn’t fundamentally different from what you’d get with standard all-purpose flour, but it’s meaningfully worse than what you’d get from less processed whole grains like oats, barley, or bulgur, which retain their bran and fiber.
If you’re eating 00 flour in a complete meal (pizza with toppings, pasta with sauce containing fat and protein), the glycemic impact is blunted. Fat, protein, and fiber from other ingredients slow glucose absorption. A slice of Neapolitan pizza will affect your blood sugar less dramatically than eating the same amount of plain cooked dough.
Fiber and Micronutrient Content
Because 00 flour is milled from the starchy endosperm of the wheat kernel with most of the bran and germ removed, it’s low in fiber, B vitamins, iron, magnesium, and zinc. These nutrients are concentrated in the parts of the grain that get stripped away during refining.
In the United States, many white flours are sold as “enriched,” meaning B vitamins (thiamin, riboflavin, niacin, folic acid) and iron are added back after milling. This is standard for most supermarket all-purpose flour. However, enrichment is not mandatory for all flour products. The FDA requires specific nutrient levels only in flour labeled “enriched.” Imported Italian 00 flours typically are not enriched, since Italy does not have the same fortification standards. This means your 00 flour may contain less folic acid and iron than the all-purpose flour already in your pantry. If you bake frequently with 00 flour as your primary flour, you could be getting fewer of these added micronutrients than you would with a domestic enriched flour.
Is 00 Flour Easier to Digest?
You’ll sometimes see claims that 00 flour is gentler on the stomach because of its fine texture or different gluten structure. The evidence for this is thin. Research on how flour processing affects gluten has found that mechanical work and heat can change gluten protein structure, making some proteins less soluble and altering the ratio of different gluten components. Certain processing methods (like oven treatment or microwaving) reduced markers associated with celiac disease immune response by 22% to 46% in lab testing. But these reductions came from specific heat treatments, not from the milling fineness that defines 00 flour.
In terms of actual digestibility measured in the lab, most flour treatments showed no significant change compared to untreated flour. The one exception was extrusion (a high-pressure industrial process unrelated to 00 milling), which showed a small decrease in digestibility. There’s no strong evidence that 00 flour is meaningfully easier or harder to digest than other refined wheat flours. If wheat bothers your stomach, 00 flour will likely bother it too.
How 00 Flour Compares to Other Flours
- All-purpose flour: Nutritionally very similar. Both are refined, low in fiber, and high-glycemic. The main difference is particle size and texture in baking. U.S. all-purpose flour is more likely to be enriched.
- Whole wheat flour: Retains the bran and germ, providing significantly more fiber, B vitamins, magnesium, and iron. Has a similar glycemic index when finely ground, but habitual whole-grain consumption is associated with lower fasting insulin and better metabolic markers.
- Ancient grain flours (kamut, spelt, einkorn): Often higher in protein and minerals. Kamut flour has about 40% more protein than whole wheat and a glycemic index roughly half that of 00 flour. These work in some pizza and pasta recipes, though the texture differs.
- Semolina flour: Coarser grind from durum wheat, higher in protein, and produces a firmer texture. Slightly better nutritional profile than 00 but still a refined flour.
Using 00 Flour Without Overthinking It
If you use 00 flour occasionally for homemade pizza or fresh pasta, it’s not a meaningful health concern. The quantities involved in a few meals per week are modest, and the flour is almost always eaten as part of a mixed meal with other ingredients that slow its glycemic impact.
Where it matters more is if 00 flour becomes your default flour for daily baking, replacing enriched or whole-grain options. Over time, that shift means less fiber, fewer micronutrients, and a higher glycemic load across your diet. If you’re managing blood sugar, trying to increase fiber intake, or eating a lot of flour-based foods, swapping in whole wheat or ancient grain flour for some of your baking makes a measurable difference. For the occasional pizza night, 00 flour does exactly what it’s supposed to do, and the nutritional cost is negligible.