Perhaps you are curious which fruits and vegetables are low on the glycaemic index as you’re hoping to reduce your intake of sugar, processed grains and other “high glycaemic foods” in general or to reach a healthier weight? Or your doctor recently recommended a low glycaemic diet to help treat a condition you’re dealing with, such as high cholesterol or diabetes? No matter what your reason is for wanting to eat a better diet overall — whether it’s for heart health, fat loss, more stabilized moods, or to reduce cravings, a low glycaemic index diet is likely to be beneficial in several ways, some you might not even expect.
Reducing your intake of high glycaemic foods (think sugary cereals, rolls, desserts, or sweetened drinks) can open more room in your diet for the types of foods you really need to get all the essential nutrients you require. Choosing unprocessed foods that have a low glycaemic load — including plenty of veggies, healthy fats, and clean proteins — also helps you feel more energized throughout the day and makes it much less likely you’ll overeat due to cravings for more carbs, resulting in blood sugar swings.
Certain diet regimes are another reason people focus on low glycaemic foods. Keto diet regimes have become very popular in recent years and in general, one focuses on low GI vegetables rather than fruits, since fruits usually contain more sugar. Good choices when picking fruit allowed on Keto are berries (strawberries, blueberries, raspberries, and blackberries, starfruit, avocados, and tomatoes. Top keto-friendly vegetables include broccoli, cabbage, cauliflower, Bok choy, asparagus, Brussel sprouts, cucumber, and celery. Have a look at our lists and chart at the end of this blog for a guide on low, medium, and high fruits and vegetables.
Proponents of the Candida diet theorize that sugar is one of the main causes of candida overgrowth. Candida feeds on sugars; the more sugar available to the cells, the easier and faster they can grow and expand their colonies. For this reason, the Candida diet recommends avoiding sugar of any kind, whether it’s from cake, lollies, and cookies or from a nutritious source like fruit. Traditionally they recommend not having any type of food normally classified as a fruit. This means no apples, pears, oranges, mangoes, blueberries, kiwis, melons, strawberries, grapes, or grapefruit. Where any form of fruit — fresh, frozen, canned, or dried — is off-limits. However, there are a few exceptions, most of them of a technical nature. You can eat foods biologically classified as fruits but commonly considered vegetables. This group includes tomatoes, eggplants, cucumbers, peppers, okra, and avocados. Please see our blogs on Candida for further information.
According to the University of Maryland Medical Centre, the diet may not actually get rid of candida, but it may improve symptoms because it’s a healthy diet that limits the intake of processed foods, added sugars, white flours and other foods that are low in nutrients. However, fruit is a healthy food that’s high in fibre and essential vitamins and minerals. Cutting out processed foods and added sugars may go a long way toward improving your symptoms without the need to give up fruit. So, some anti-candida diets allow for low GI fruits particularly as you reintroduce foods you will start with low GI fruits and vegetables first.
Beginning in the 1980s, researchers developed a method of testing individual foods to see how much they raised blood glucose, resulting in a scale called the glycaemic index or GI. Many fruits and vegetables contain minimal to moderate amounts of carbohydrates and therefore have a low GI, but some fruits and starchy vegetables are on the high end.
Glycaemic Index Explained
The glycaemic index is a tool that’s used to indicate how a particular food affects blood sugar (or glucose) levels. The definition of the glycaemic index (GI) is “a measure of the blood glucose-raising potential of the carbohydrate content of a food compared to a reference food (generally pure glucose, or sugar).”
The aim of the glycaemic index is to provide health-conscious eaters with a tool for estimating how much impact a food will have on blood glucose levels. To do this, researchers commonly use pure glucose as the benchmark, measuring its effect on blood glucose and using that to set the bar. With this as a reference point, researchers anywhere can test a food, measure its impact on the blood glucose levels of volunteers, and then compare it to pure glucose.
Foods are assigned a glycaemic index/glycaemic load number that can be compared to pure glucose, which serves as the benchmark for all other foods. Pure glucose has a glycaemic index number of 100, indicating that it’s very rapidly broken down into glucose once eaten and then either sent to cells to be used for energy, saved in the muscles as glycogen for later use or stored inside fat cells when there’s a surplus.
A food with a GI of 50 or less is “low GI,” anything from 50 to 70 is considered “moderate,” and a GI of 70 or greater is considered “high.” To complicate matters, produce items don’t always test at the same GI level. Some varieties of a given fruit or vegetable may have more starches or sugars, and other factors such as the ripeness of the test food and the length of time it’s been in storage can also affect the end result.
All foods containing glucose, fructose, or sucrose (various forms of carbohydrates or sugars) can be classified as high GI, moderate GI, or low GI. (1) The glycaemic index values of all foods range from 0–100:
- High GI = 70 to 100
- Medium GI = 50 to 70
- Low GI = below 50
Whenever we eat any type of carbohydrate, whether it’s pure table sugar or a cup of fresh vegetables, the molecules in the food are broken down as they’re absorbed, which impacts blood glucose levels and insulin release. All carbohydrates cause release of the hormone insulin from the pancreas, which has the job of picking up and sending glucose that’s present in the blood throughout the body to be used or stored away.
How drastically and quickly a carbohydrate causes this process to happen depends on how quickly its glucose is broken down; some carbs that are low on the glycaemic index (like veggies and 100 percent whole grains, for example) cause a smaller and more gradual rise in blood glucose, while carbs that have a high glycaemic score (like soda and white rice) cause rapid glucose absorption and high insulin release. Carbohydrates of all kinds are the main dietary source of glucose, but not all carbs are created equal. For example, good choices include brown or wild rice, sweet potatoes, sprouted ancient grains, legumes, and beans, while poor choices include soda and ice cream.
Choosing low glycaemic foods can help prevent persistently high insulin levels, which are associated with health problems like type 2 diabetes or prediabetes, heart disease, hypertension, and obesity.
Glycaemic Index vs. Glycaemic Load
Finally, it’s important to understand that a glycaemic index score is a bit different than a glycaemic load (GL) score. GL considers the GI score of a particular carbohydrate but also considers how the carbs in the food affect blood sugar levels when eaten in average portions (not just in 100-gram servings). Many of the fruits and vegetables that are high on the glycaemic index scale come in low on the glycaemic load scale.
Overall, a food’s glycaemic load score may be a better predictor of whether or not it is a healthy food choice. Contributing factors are when a food is eaten generally in moderate amounts or as part of a whole meal choice. Here’s the range of GL scores to consider when making choices about the carbs in your diet:
- High GL = 20 +
- Medium GL = 11 to 19
- Low GL = 10 or less
Low GI Diet Principles
As you can see, the types of carbs included in your diet typically have a big impact on how you feel after eating the food, including how satisfied or full you are, how quickly you get hungry again or experience cravings for more, and how much of a lift in energy the food tends to provide for you. The goal of eating a low glycaemic diet is to consume more foods that only have a mild, more prolonged impact on blood sugar since they’re broken down slower and provide more sustained energy.
Here are several key principles and tips to keep in mind when reducing the glycaemic load of your diet:
- Eat carbs that require zero or very little “processing” — One of the biggest factors when it comes to determining a food’s glycaemic load/index score is whether it’s eaten in its original state (such as veggies that are raw or mildly cooked) versus whether it’s been processed (like bread, soda, and cereal). The more that a food is refined, the quicker its sugar/starch molecules will impact blood sugar. For example, the smaller a starch granule is, the easier and quicker it is for the digestive system to convert it to glucose.
- Get more fibre — Fibre in “whole foods” acts as a protective barrier when it comes to stabilizing blood sugar, slowing down digestion, and protecting sugar and starch molecules from rapid absorption due to enzyme release. The more refined a food is, the less fibre it’s likely to contain. For example, processed grains and sugar supply very little fibre, if any. On the other hand, fresh veggies, fruit, and soaked/sprouted beans or legumes provides lots. Here are some of the best high-fibre foods: artichokes, green leafy vegetables, avocado, cruciferous veggies, chia and flax, and sweet potatoes.
- Make your grains 100 percent unprocessed and ideally soaked/sprouted — Make a habit of reading ingredient labels whenever you eat something that comes in a package or box, such as bread, pasta, cereal, or wraps. Look for the words “100 percent whole grain” as the very first ingredient, and check for any indication that sugar has been added, keeping in mind that added sugar can go by dozens of different names. Try to eat foods with just one or very little ingredients, which means they’re more likely to contain natural fibre and less likely to spike blood sugar.
- Get more starch from root veggies — Some people respond poorly to eating grains, especially wheat, which contains the protein called gluten that can be hard to fully digest. You can get plenty of healthy carbohydrates, fibre, and antioxidants too from eating root veggies like sweet potatoes, beets, turnips, and winter squash.
Combine carbs with protein and fat — How you combine different foods is very important when it comes to digestion and blood sugar management. Pairing low GI carbs with a healthy source of fat and protein (such as olive or coconut oil, eggs, and fish, for example) can be helpful for managing blood sugar levels, energy, and hunger. Try to include a source of each with each main meal and at least some protein or healthy fat with snacks.
FRUIT AND VEGEATBLE GI GUIDE
Low GI Fruits
Many fruits have a low GI value, which makes them good choices for keeping your blood sugar levels under control and maintaining optimal health.
For example, cherries, apples, pears, peaches, grapefruit, plums, grapes, kiwifruits, oranges, strawberries, and prunes all have a GI below 55, which makes them good options for a low glycaemic index diet.
Medium GI Fruits
Mangoes, bananas, raisins, papaya, figs, and pineapple have a medium GI value, which ranges between 56 and 69.
Although these fruits do not produce a sharp rise in your blood sugar levels like a high GI food would, their influence over your blood sugar levels is significantly higher compared to low GI fruits.
High GI Fruits
Watermelon has a GI of 80 and dates have a GI of 103, making them high GI fruits.
Eating these fruits, especially in large quantities, can cause your blood sugar levels to rise quickly. High GI foods should be consumed in moderation only.
Low GI Vegetables
Most vegetables have a low GI, with only a few exceptions. If you are aiming to lower your dietary GI, you can include an abundance of vegetables such as carrots, eggplants, tomatoes, onions, mushrooms, broccoli, cauliflower, lettuce, green beans, bell peppers, summer squash and cabbage.
These vegetables will help you keep your blood sugar levels more stable.
Medium GI Vegetables
Beetroot is one of the only vegetables with a medium GI value of 64. It can be part of a healthy and balanced low glycaemic index diet if eaten in moderation.
High GI Vegetables
Pumpkins and parsnips have a high GI, which is above 70. All potatoes, whether they are baked, mashed, or fried, also have a high GI value. Eating high GI vegetables can result in a sharp increase in your blood sugar levels.
If a low glycaemic diet seems overwhelming or restrictive, remember that your diet doesn’t have to be complicated to be healthy. Keep things simple by using common sense and choosing source of carbs that are the least processed and contain the fewest added ingredients. Sources of carbohydrates like fruits, ancient whole grains, sweet potatoes, beans, etc., don’t need to be removed from your diet — it’s all about balance and eating real foods!
Follow my recommendation to eat plenty (and a variety of) real foods and avoid fake foods, then you won’t have to pay too much attention to calculating GI scores, calories, grams, etc.
Eat foods the way they’re found in nature, listen to your body, and pay attention to your own body’s feedback and individual symptoms to know what’s best for you.
Bach. Chiropractic, Bach. App Clinical Science
Registered internationally, no longer practicing as a chiropractor in Australia.