Boiled Sweet Potato Glycemic Index, Glycemic Load, and Blood Sugar Response Chart

Blood Glucose Response Chart

Boiled sweet potato has a low Glycemic Index (GI) of 46 and a Glycemic Load (GL) of 6.78 per 100g. This makes it one of the best whole-food carbohydrate options, especially when prepared using the boiling cooking method.

Sweet potato (Ipomoea batatas) is a nutrient-rich, starchy root vegetable commonly consumed across the world. When boiled, sweet potatoes retain their natural fiber and moisture, helping reduce the concentration of digestible carbohydrates. The boiling method also promotes the formation of resistant starch, which slows digestion and leads to a gentler glycemic impact.

Unlike baking or frying, boiling sweet potatoes avoids caramelizing sugars or adding fat, keeping the nutritional profile intact. This simple cooking method enhances sweet potato’s role as a healthy, filling carbohydrate in any diet.

A 100g serving of boiled sweet potato, cooked with the boiling method, delivers just 14.74g grams of net carbs, resulting in a low Glycemic Load.

Let's examine the nutritional profile and glycemic impact of boiled sweet potato below.

Boiled Sweet Potato Nutritional Profile (per 100g)

• Calories: 94 kCal
• Carbohydrates: 17.14g
• Dietary Fiber: 2.40g
• Net Carbohydrates: 14.74g
• Protein: 1.33g
• Fats: 2.50g
• Sugar: 5.53g

How Boiling Affects Sweet Potato’s Digestibility

Boiling sweet potatoes gelatinizes their starch, enhancing digestibility. When the boiled sweet potato is cooled, some of that starch retrogrades into resistant starch, which slows glucose absorption and flattens the post-meal blood sugar curve.

Boiling is a moist-heat cooking method that involves submerging food in water heated to 100°C (212°F). This method uses both high temperature and direct contact with water to transfer heat evenly throughout the food. For starchy vegetables like sweet potatoes, boiling triggers a process called gelatinization, where the starch granules absorb water and swell, becoming easier to digest.

In addition, boiling sweet potatoes preserves their natural moisture and fiber content, which contributes to a lower concentration of digestible carbohydrates per gram. When cooled after boiling, sweet potatoes also form resistant starch, a slow-digesting carbohydrate that helps moderate the glycemic response.

Unlike dry-heat methods like roasting or frying, boiling doesn't concentrate sugars or introduce added fats, making it the most effective cooking method for preserving the glycemic benefits of sweet potatoes.

Gelatinized Starch: The Key to Boiled Sweet Potato’s Low GI

The gelatinized starch in boiled sweet potato is more rapidly digestible, which would normally raise GI. Yet, due to its moderate net carbs and high fiber, the Glycemic Load stays low. This balance makes boiled sweet potato uniquely blood sugar-friendly.

Starch is the main type of carbohydrate found in sweet potatoes. It’s made up of long chains of glucose molecules, tightly packed inside plant cells. In its raw form, starch is hard to digest because our digestive enzymes can’t easily access those compact granules.

That’s where boiling comes in. When sweet potatoes are boiled, the heat and water cause the starch granules to swell, break apart, and absorb water - a process known as gelatinization. This makes the starch more digestible and releases glucose more easily during digestion.

Now, here's the interesting part ...

While gelatinized starch is normally digested quickly (which would raise the Glycemic Index), boiled sweet potato still maintains a low GI.

Why?

Because its fiber content, water retention, and moderate net carbs all help slow down glucose absorption.

Even better, when boiled sweet potatoes are cooled after cooking, some of the gelatinized starch undergoes retrogradation, turning into resistant starch, which slows digestion even further and keeps the Glycemic Load low.

So although boiling makes sweet potato starch easier to digest, it also sets the stage for stable blood sugar levels, especially when paired with cooling.

Boiled Sweet Potato Glycemic Index (Why It's Naturally Low)

Boiled sweet potato has a low Glycemic Index (GI) of 46, making it one of the most blood sugar-friendly carbohydrate-rich vegetables you can eat.

This low GI score reflects how boiled sweet potatoes, when prepared using the boiling cooking method, release glucose more slowly compared to other starchy foods. Instead of causing a rapid spike, boiled sweet potato supports a gradual, steady rise in blood sugar.

Glycemic Index measures how fast carbohydrates in a food increase blood glucose levels, on a scale from 0 to 100. At 46, boiled sweet potato ranks in the low-GI category, well below baked or fried versions.

What makes the GI of boiled sweet potato so favorable?

• Gelatinized starch improves digestibility
• Resistant starch slows glucose absorption
• Water and fiber content reduce overall carb density

Thanks to this natural balance, boiled sweet potatoes are easily digested yet gentle on blood sugar.

However, Glycemic Index only reflects speed of absorption. To understand how much glucose a portion actually delivers, we also look at Glycemic Load, a more complete measure of blood sugar impact.

How Much Boiled Sweet Potato Should You Eat?

For most people, a 100g serving of boiled sweet potato (with a low Glycemic Load of 6.78) is suitable, even for pre-diabetics and diabetics, as it provides a modest, steady glucose impact, but portion control remains key for blood sugar management.

GI tells us how fast carbs act; Glycemic Load tells us how much glucose impact they cause per serving. Boiled sweet potato contains 14.74g of net carbs per 100g, which is the portion actively influencing blood sugar.

Using the formula:

we get a GL of 6.78. A low glycemic burden, even with rapid digestibility.

This makes boiled sweet potato a well-balanced choice, with both speed and quantity in check.

Serving sizes of boiled sweet potato and Glycemic Load:

Boiled Sweet Potato Postprandial Glucose Response

Boiled sweet potato produces a mild postprandial glucose response due to its low Glycemic Index and Glycemic Load, resulting in a steady rise in blood sugar rather than a sharp spike.

The postprandial glucose response refers to the actual change in blood sugar levels that occurs after eating a food like boiled sweet potato. Unlike Glycemic Index or Glycemic Load, which are standardized metrics, this response reflects what happens in real time within the body—and is shaped by both.

A food’s GI sets the pace, showing how quickly glucose enters the bloodstream, while its GL defines the load, or total glucose exposure per serving. With a low GI, boiled sweet potato leads to a gentle, controlled rise in blood sugar rather than a sharp spike. This makes it a metabolically favorable choice for maintaining stable glucose levels.

The postprandial response is the end-point expression of the entire glycemic pathway, driven by the way the food is cooked, how digestible its carbs are, and how much is consumed. For boiled sweet potato, this means a predictable, manageable blood sugar impact, ideal for those aiming to regulate glucose levels over time.

Summary

Boiled sweet potato, through starch gelatinization and moderate levels of rapidly digestible carbohydrates, has a low Glycemic Index (46) and Glycemic Load (6.78 per 100g), resulting in a gentle post-meal blood sugar response, making it a smart, balanced carb choice for most diets, including for pre-diabetic and diabetic individuals.