What Has the Highest Glycemic Load?

October 28, 2025 •

5 min read

A single serving of instant mashed potatoes can have an exceptionally high glycemic load (GL) of over 66, revealing a significant impact on blood sugar levels. This startling figure underscores the importance of understanding what has the highest glycemic load and how these foods affect your overall health.

Quick Summary

This article identifies foods with the highest glycemic load values, examining how processed carbohydrates and sugary drinks affect blood sugar levels. It provides practical strategies for managing glycemic load through informed dietary choices and offers balanced alternatives for better metabolic health.

Key Points

Instant Mashed Potatoes: This is arguably the highest glycemic load food due to its highly processed nature and rapid starch digestion, resulting in a GL of over 66 per serving.
Refined Grains: White rice and other refined grain products, like white bread and certain crackers, lose their fiber during processing, leading to a high glycemic load and quick blood sugar spikes.
Sugary Drinks: Beverages containing high levels of simple sugars, such as soda, some fruit juices, and glucose-based sports drinks, have a very high glycemic load and can cause dramatic blood sugar fluctuations.
Cooking Matters: The method of cooking, especially for starchy foods like potatoes, significantly impacts glycemic load. For example, baked russet potatoes have a high GL, but boiling and cooling potatoes increases resistant starch, lowering the GI and GL.
Lowering GL is Achievable: You can reduce your overall dietary glycemic load by choosing whole foods, combining carbohydrates with fiber, protein, and fat, and controlling your portion sizes.
GL is More Accurate Than GI: While Glycemic Index (GI) is useful, Glycemic Load (GL) is often considered more reliable because it accounts for both the food's quality of carbs and the quantity consumed in a serving.

Understanding Glycemic Load (GL)

Glycemic Load (GL) provides a comprehensive picture of a food's impact on your blood sugar, unlike the Glycemic Index (GI), which only measures how quickly a food raises blood sugar. GL considers both the quality of the carbohydrate (GI) and the quantity of carbohydrates in a typical serving. It is calculated by multiplying the food's GI by the number of digestible carbohydrates in a serving, then dividing by 100. A high GL (20 or more) indicates a food that will likely cause a significant blood sugar spike, while a low GL (10 or less) suggests a more stable, gradual rise.

The Highest Glycemic Load Foods

Foods with the highest glycemic load are often highly processed carbohydrates and sugary beverages that are quickly digested and absorbed by the body. They typically contain low fiber and high levels of refined starches or added sugars. Understanding these foods is a critical step toward managing blood sugar effectively.

Instant and Highly Processed Starches

Instant Mashed Potatoes: Dehydrated potato flakes, reconstituted with water, can have a GL of over 66 per serving, one of the highest values recorded. The processing makes the starch highly accessible for rapid digestion, leading to a massive spike in blood glucose.
Baked Russet Potatoes: Even a whole, baked russet potato is surprisingly high, with a GL of 33, despite its fiber content. The baking process breaks down the potato's starch, making it more digestible and increasing its glycemic impact.
White Rice: This staple grain has a high GL, with a standard serving causing a significant blood sugar rise due to its removed bran layer. The GL of white rice can be around 35, though it varies by type and preparation method.
Pancakes: Made from refined white flour, a stack of pancakes is a high-carb, low-fiber breakfast that can cause a major blood sugar surge. A single medium-sized pancake can have a GL of around 39.

Sugary Beverages and Confections

Glucose Drinks: Drinks containing pure glucose or high amounts of other simple sugars, like certain sports or energy drinks (e.g., Lucozade), can have a GL of 40 or higher, depending on the serving. They are designed for rapid absorption, which is why they are used to treat hypoglycemia, but they are detrimental for regular consumption.
Rice Syrup: This concentrated sweetener, though often perceived as natural, can have a GL of 77 or higher, putting it at the top of the list for sugars.
Dates: Although a natural fruit, dried dates are a concentrated source of sugar and can have a high GL of 25 per 2 oz serving.

Processed Grains and Snacks

Rice Cakes and Crackers: These lightweight, puffed snacks are made from highly processed grains and digest rapidly, causing quick blood sugar spikes. A few rice cakes can contribute a significant GL to your diet.
Cornflakes: A common breakfast cereal, cornflakes have a high GI, contributing to a GL of 20 or more in a single cup.
Pretzels and Crackers: Many pretzels and crackers are made from refined flour, giving them a high GI and, consequently, a high GL.

High vs. Low Glycemic Load Food Comparison

To highlight the difference, consider how various food choices stack up. Making simple swaps can significantly lower your total glycemic load.


Food Item	Typical Serving Size	Glycemic Index (GI)	Glycemic Load (GL)	Classification	Notes
Instant Potatoes	1 cup	87	66.1	High	Highly processed, rapid digestion
White Rice	1 cup, cooked	70	56	High	Refined grain, lacks fiber
Pancake	1 (6" diameter)	67	39	High	Made from refined flour
Lucozade	1 cup	95	40	High	Concentrated glucose drink
Baked Russet Potato	1 medium	111	33	High	Cooking method increases GI
White Spaghetti	1 cup, boiled	46	20	Medium	Longer cooking increases GI
Brown Rice	1 cup, cooked	50	20	Medium	Less processed, more fiber
Oatmeal (Rolled)	1 cup, cooked	55	13	Low	Whole grain, good fiber source
Lentils (Boiled)	1 cup	29	7	Low	High fiber, slows digestion
Pearled Barley	1 cup, boiled	28	11	Low	High fiber, healthy grain
Apple (Raw)	1 medium	39	6	Low	High in fiber
Peanuts	1 oz	18	1	Low	Low in carbs, high in fat/protein

The Health Risks of a High-GL Diet

Consistently consuming high-GL foods can have significant negative health consequences. The repeated cycle of blood sugar spikes and crashes can lead to a state of chronic hyperglycemia and hyperinsulinemia. Over time, this can cause insulin resistance, a key precursor to Type 2 diabetes. Studies have also linked high-glycemic diets to an increased risk of cardiovascular disease, certain cancers, and weight gain. The rapid fluctuation in blood sugar levels also causes cravings and overeating, making weight management more difficult.

Strategies for a Lower Glycemic Load

Managing your dietary GL doesn't mean eliminating all high-carb foods. Instead, it involves making smarter choices about what you eat and how you prepare it. The key is to slow down the absorption of glucose into your bloodstream.

Choose whole over refined: Opt for whole grains like brown rice, oats, and barley over their processed white counterparts. These whole foods contain more fiber, which slows digestion and leads to a lower GL.
Combine with protein and fat: Pairing high-GI foods with protein, healthy fats, or fiber can effectively lower the overall GL of a meal. For example, adding nuts and seeds to your oatmeal can reduce the meal's glycemic impact.
Control portions: The amount of food you eat directly affects the GL. Limiting the portion size of high-GL foods like white rice or potatoes is an easy way to mitigate their effect.
Modify cooking methods: How a food is cooked impacts its GI and GL. For example, cooking pasta 'al dente' (firm) rather than until very soft results in a lower GI. Similarly, cooking and cooling potatoes increases resistant starch, which is digested more slowly.
Prioritize low-GI foods: Build your meals around low-GI foods like leafy greens, legumes, and most fruits, which have a minimal impact on blood sugar.

To learn more about healthy eating for blood sugar management, consult authoritative sources like the Linus Pauling Institute.

Conclusion

While a variety of factors influence blood sugar, the glycemic load is a powerful tool for predicting a food's impact. The foods with the highest glycemic load are typically highly processed, refined carbohydrates and sugary drinks, such as instant mashed potatoes, white rice, and glucose beverages. By understanding and identifying these items, you can implement effective dietary strategies to lower your total glycemic load. Prioritizing whole, fiber-rich foods, controlling portion sizes, and combining high-GL items with healthy fats and protein are all practical steps toward promoting stable blood sugar and long-term metabolic health.

Frequently Asked Questions

The Glycemic Index (GI) ranks carbohydrates on a scale of 0 to 100 based on how quickly they raise blood sugar, but does not account for portion size. Glycemic Load (GL) is a more comprehensive measure that factors in both the food's GI and the amount of carbohydrates in a typical serving, providing a more realistic picture of its impact on blood sugar.

Yes, cooking methods significantly impact a food's glycemic load. For instance, boiling a potato and then cooling it increases its resistant starch, which lowers its GL. In contrast, baking a potato makes its starch more easily digestible, increasing its GL.

While watermelon has a relatively high glycemic index, its glycemic load is low because it consists mostly of water and has a low carbohydrate density. Therefore, a typical serving of watermelon will not cause a significant blood sugar spike.

Brown rice and parboiled rice generally have a lower glycemic load than standard white rice. This is because their processing retains more fiber, which slows down digestion and glucose absorption.

Processed foods like instant oatmeal, crackers, and white bread have a higher glycemic load because the processing often removes fiber and other nutrients. This makes the carbohydrates easier and quicker for the body to digest, leading to a faster and more significant blood sugar increase.

To reduce a meal's glycemic load, pair high-carb foods with sources of fiber, protein, and healthy fats. For example, adding vegetables, beans, and lean protein to a serving of rice can create a more balanced meal that slows down glucose absorption.

Yes, portion size is a critical factor in determining glycemic load. The GL calculation directly incorporates the amount of carbohydrates in a serving, so eating a larger portion of a medium-GI food can result in a higher GL than eating a small portion of a high-GI food.