A healthy balanced diet should always include some fruit since they are some of the healthiest carbohydrates a person can consume (yes fruits and vegetables are carbohydrates!). They contain antioxidants, vitamins, phytonutrients and fibre which keeps blood sugar in balance. I recommend consuming 2-3 servings of fruits daily with a lower sugar content and small amount of fruit occasionally with a higher sugar content. For the most efficient digestion of fruits, they should be eaten alone and before other food (eating fruit after a meal often causes indigestion and gas). They are nicely digested with a full fat organic yogourt (3-4%). Choosing low glycemic (sugar) foods becomes especially important for Type 1 and Type 2 diabetics or glucose sensitive individuals (those prone to hypoglycemia). The question then becomes, which fruits have the lowest But how do we measure the sugars in a particular fruit, and which fruits have the lowest amounts?
First of all, it’s important to understand how the sugars in fruit are measured. We don’t actually take a piece of fruit, examine it in the lab, and quantify the grams of sugar in each portion. What actually happens is that we measure the effect that that fruit has on our blood sugar levels. There are two ways to represent this – Glycemic Index (GI) and Glycemic Load (GL). First I’ll explain how these measures work, and at the end of article I have included two tables with the numbers for various fruits.
Glycemic Load Is A More Useful Measure Than Glycemic Index
The Glycemic Index of a food is a numerical unit describing how far eating a food will raise one’s blood sugar level; effectively, it represents how ‘sugary’ the food is. The Glycemic Index uses a scale from 0 to 100, where 100 is pure glucose. A food which has a high GI will cause a large increase in blood sugar, while a food with a lower GI will not have much impact at all. As a rough basis, mid-50s to mid-60s in a food’s GI is considered average, while 70 and above is considered high. Foods with a GI of less than 55 are considered to have a low glycemic index, and thus will have smaller impact on blood sugar levels.
The main problem with the Glycemic Index is that it does not factor in typical portion sizes. In fact, it standardizes each food to include 50 grams of carbohydrates. This leads to some peculiar distortions. For example, to obtain 50 grams of carbohydrates you would need either 2.8 ounces of a Snickers bar or 35 ounces of pumpkin. It hardly seems fair to compare the two when these portion sizes are so unrealistic!
In 1997, researchers at Harvard University introduced the concept of Glycemic Load with the aim of solving this problem. The Glycemic Load seeks to balance the Glycemic Index by accounting for serving size. Let’s take a watermelon as an example. It has a high GI, as the carbohydrate will increase blood sugar levels rapidly, but it contains a relatively small amount of the carbohydrate, meaning that it has a low glycemic load.
A food’s Glycemic Load is calculated directly from its Glycemic Index. We simply take the food’s Glycemic Index, divide it by 100, and multiply it by the grams of carbohydrate (excluding fiber) in a typical serving size. A GL of above 20 is considered high, the 11-19 range is considered average, and below 11 is low.
Let’s look again at watermelon. It has a Glycemic Index of 72, which is relatively high. However, a typical serving size only has 5 grams of carbohydrate. This means we can calculate the Glycemic Load like this: 72/100*5 = 3.6. Although the Glycemic Index is high, the Glycemic Load is relatively low. Which one is more useful to us? The Glycemic Load.
Watermelons are an unusual case, insofar as they have a high Glycemic Index (above 70 is considered high), yet have a low Glycemic Load (below 11 is low). This is not common, as most foods with a high GI will have a correspondingly high GL.
The Glycemic Load Of Fruits
Here are two tables containing the Glycemic Load of various fruits, taken mostly from the American Journal of Clinical Nutrition in 2002 (full version here) and the American Diabetes Association in 2008 (full version here). Remember that a GL of more than 20 is considered high, a GL of 11-19 is considered average, and a GL of below 11 is considered low. I have created a table showing the fruits in alphabetical order, and one showing them ordered by Glycemic Load.
Fruits (Alphabetical)
| Fruit | Glycemic Load | Serving Size (grams) |
|---|---|---|
| Apple | 6 | 120g |
| Apricot | 3 | 120g |
| Banana | 11 | 120g |
| Blueberries | 5 | 120g |
| Cantaloupe | 4 | 120g |
| Cherries | 9 | 120g |
| Dates | 18 | 60g |
| Figs | 16 | 60g |
| Grapefruit | 3 | 120g |
| Grapes | 11 | 120g |
| Guava | 4 | 120g |
| Kiwi | 7 | 120g |
| Lemon | 3 | 120g |
| Lime | 1 | 120g |
| Mango | 8 | 120g |
| Nectarines | 4 | 120g |
| Oranges | 4 | 120g |
| Peach | 5 | 120g |
| Pear | 4 | 120g |
| Pineapple | 6 | 120g |
| Plum | 5 | 120g |
| Prunes | 10 | 60g |
| Raisins | 28 | 60g |
| Strawberry | 1 | 120g |
| Watermelon | 4 | 120g |
Fruits (By Glycemic Load)
| Fruit | Glycemic Load | Serving Size (grams) |
|---|---|---|
| Lime | 1 | 120g |
| Strawberry | 1 | 120g |
| Apricot | 3 | 120g |
| Grapefruit | 3 | 120g |
| Lemon | 3 | 120g |
| Cantaloupe | 4 | 120g |
| Guava | 4 | 120g |
| Nectarines | 4 | 120g |
| Oranges | 4 | 120g |
| Pear | 4 | 120g |
| Watermelon | 4 | 120g |
| Blueberries | 5 | 120g |
| Peach | 5 | 120g |
| Plum | 5 | 120g |
| Apple | 6 | 120g |
| Pineapple | 6 | 120g |
| Kiwi | 7 | 120g |
| Mango | 8 | 120g |
| Cherries | 9 | 120g |
| Prunes | 10 | 60g |
| Banana | 11 | 120g |
| Grapes | 11 | 120g |
| Figs | 16 | 60g |
| Dates | 18 | 60g |
| Raisins | 28 | 60g |
Bear in mind that a high GI and GL does not necessarily mean that fruits are unhealthy and should be avoided.
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