The lowest glycemic index foods are those that score 55 or less on the 0 to 100 GI scale, and most of them are proteins, non-starchy vegetables, nuts, legumes, and a surprising handful of fruits. GI is a useful starting filter for blood sugar friendly eating, but glycemic load and real-world meal pairing matter even more.
What the Glycemic Index Measures
The glycemic index ranks carbohydrate-containing foods from 0 to 100 based on how quickly 50 grams of available carbohydrate raises blood glucose relative to a reference (usually pure glucose, scored 100). Values of 55 or below are considered low, 56 to 69 medium, and 70 or higher high. The ranking was developed at the University of Toronto in the early 1980s and is now maintained by a searchable database at the University of Sydney.
GI captures quality of carbohydrate but not quantity. A food can be high GI and still barely move your blood sugar if the serving contains very few grams of carbs. That gap is why glycemic load was introduced.
Ranked List of Low-GI Foods
The table below rounds up some of the lowest-GI foods in common supermarket categories. Values are averages from the University of Sydney database; your personal response can differ.
| Food | Avg. GI | Typical Serving | Est. Glycemic Load |
|---|---|---|---|
| Hummus | 6 | 2 Tbsp | 0 |
| Peanuts | 14 | 1 oz | 1 |
| Soybeans (cooked) | 16 | 1/2 cup | 1 |
| Plain Greek yogurt, unsweetened | 11 | 3/4 cup | 1 |
| Cashews | 22 | 1 oz | 3 |
| Cherries | 22 | 1 cup | 4 |
| Lentils | 29 | 1/2 cup cooked | 5 |
| Kidney beans | 29 | 1/2 cup cooked | 7 |
| Chickpeas | 28 | 1/2 cup cooked | 8 |
| Barley, pearled | 28 | 1/2 cup cooked | 10 |
| Apple | 36 | 1 medium | 6 |
| Pear | 38 | 1 medium | 4 |
| Whole milk | 39 | 1 cup | 5 |
| Carrots (raw) | 39 | 1 cup | 3 |
| Steel-cut oats | 42 | 1/2 cup cooked | 9 |
| Sweet potato (boiled) | 46 | 1/2 cup | 11 |
Why Glycemic Load Is Often More Useful
Glycemic load (GL) equals GI multiplied by grams of available carbohydrate per serving, divided by 100. A GL under 10 is low, 11 to 19 is medium, and 20 or higher is high. Watermelon is a classic example: its GI is about 72 (high), but a typical serving has only 11 grams of carb, producing a GL of about 8 (low). The Harvard Nutrition Source provides a full explanation with comparative tables.
For meal planning, aiming for lower GL across the day tends to produce steadier glucose than chasing a low GI for every single item. Our diet and nutrition hub translates these ideas into plate-building rules.
Categories That Cluster at the Low End
- Non-starchy vegetables: leafy greens, broccoli, cauliflower, zucchini, cucumbers, peppers, tomatoes are so low-carb they rarely get a GI score
- Legumes: lentils, chickpeas, black beans, kidney beans, soybeans typically score in the 20s and 30s
- Nuts and seeds: most score below 25 and bring fat and fiber that slow absorption further
- Dairy (unsweetened): plain yogurt and milk are naturally low-GI thanks to lactose plus protein and fat
- Low-sugar fruits: berries, cherries, apples, pears score below 40
- Intact whole grains: steel-cut oats, barley, bulgur, quinoa (GI 53) are lower than their processed counterparts
Foods That Commonly Spike Glucose
For contrast, high-GI foods worth limiting include white bread (GI 75), instant oatmeal (GI 79), cornflakes (GI 81), jasmine rice (GI 89), boiled potato (GI 78), and sweetened sports drinks (GI 78 or higher). Swapping one of these for a low-GI alternative in each meal is a common first step in prediabetes nutrition.
How to Use GI Without Overthinking It
Published GI values are averages from lab studies in people with normal glucose tolerance. Your response is shaped by sleep, stress, medications, gut microbiome, and the rest of the meal. A few practical rules reduce the need for memorizing the database:
- Fill half the plate with non-starchy vegetables
- Add a palm-sized portion of protein to every meal
- Include a source of fat (olive oil, avocado, nuts) to slow gastric emptying
- Choose intact grains over milled or instant versions
- Watch portion size for any starchy or sweet item, even if it is labeled low-GI
Low-GI Eating and A1C
Randomized trials comparing low-GI to higher-GI diets in people with type 2 diabetes have reported modest A1C reductions, typically in the 0.2 to 0.5 percent range. The effect is small but clinically meaningful when layered on top of weight management and activity. For more on A1C targets, see our A1C levels guide.
The Bottom Line
The lowest-GI foods are legumes, nuts, non-starchy vegetables, many fruits, and unsweetened dairy. Build meals around those staples, watch glycemic load rather than GI in isolation, and test your own response with a meter or CGM to personalize the list. Talk with your clinician or a registered dietitian before making major diet changes, especially if you take glucose-lowering medication. This article is educational and is not medical advice.
