Low GI Foods — What Makes a Food Low-Glycaemic Index?

There are plenty diet trends that come and go, but the glycaemic index, or GI diet, has been around for years and has proven to be effective. Following a low GI diet requires making healthy carbohydrate choices that can lead to many health benefits, including weight loss. Read on to see if the low GI diet is right for you.

In this article, you’ll find:

• What is GI?

• Why follow a low GI diet?

• How to switch to a low GI diet

• What impacts a GI rating?

• List of low GI foods

• List of high GI foods

• Benefits of a low GI diet

• Easy swaps for a low GI diet

What is the GI?

The glycaemic index is a measure of the body’s blood sugar response to a type of food. When we eat foods that contain carbs, our body breaks them down into glucose that ends up in our blood stream.

Foods that digest easily and cause more dramatic spikes in blood sugar have a higher GI rating, while high-fibre, slow-digesting foods have a lower impact on blood sugar and lower GI rating. For example, white bread would have a higher GI rating than whole grain bread.

Foods with GI scale rating of 70 or more are considered “high”, and those 55 or below are considered “low”.¹ However, the glycaemic index of a food does not reference the specific quantity – for example, watermelon has a high glycaemic index, but due to its water and fibre content, it does not greatly impact blood sugar in typical serving sizes.

Why follow a low GI diet?

People usually reference the glycaemic index of foods when they are trying to follow an overall healthy diet, lose weight, or control their intake of less healthy carbs. Following the GI diet style can help improve blood sugar control, which impacts many other aspects of health.

More frequent consumption of high GI foods, which are typically highly processed, high carbohydrate foods, can lead to weight gain and insulin resistance. ¹ Another concern about high sugar foods that are low in fibre is their impact on heart health.¹

How to Switch to low GI

While the GI rating of some foods is marked on food labels, it isn’t easy to know the exact GI rating of every single food. If you want a reference point, a Glycaemic Index Database is maintained by Sydney University. The glycaemic index is not a requirement on food labels at this time, but many labels of healthy foods may boast a low GI rating.

If you are trying to switch to a lower glycaemic index eating style, stick with high fibre fruits, vegetables, and whole grains, and less refined, white products. It may take some planning and list making. For example, before you go shopping you can consult the glycaemic index database and make a list of the foods you like that fall in to the lower GI category.

What Impacts GI rating of foods

While the GI rating of a food depends on how it’s broken down into glucose in your body, the portion size and other foods you eat alongside can change the way it’s digested. Eating pure sugar on an empty stomach has a greater effect on raising blood sugar quickly than having some sugar mixed into another food during a full meal. Fat, fibre, and protein foods slow digestion, which also slows the absorption and blood sugar response of carbohydrate foods.

Determining the GI rating of a food isn’t as simple as how sweet it tastes — for example, apples are a low GI fruit while watermelon has a much higher rating. It takes some time and research to learn the best choices in food group.

Low GI foods

When making a low GI meal plan, you can use the following list of foods from low end of the glycaemic index (less than 55).

Foods to Avoid

These are the foods with a high glycaemic index.

Benefits of low GI diet

The University of Sydney provides several claims based on research of the following a diet with low GI foods.² A summit was held in 2015 to discuss the research to support these claims, and scientists are still working on finding the best ways to implement a low-GI diet for health benefits.¹

1. Blood sugar control

Many worldwide associations recommend using the GI scale to help people choose healthier carbohydrate foods that will have less of an impact on their blood sugar.² It can be a part of meal planning or the entire basis for their diet strategy.

2. Cholesterol

Many studies have supported that foods that are high in fibre can impact cholesterol levels. Because many low GI foods are also high in fibre (like whole grains), they can be good choices for those trying to use their diet to improve their cholesterol levels.

3. Weight Management

While there are lots of studies that discuss weight loss success, choosing foods with a low GI rating will help to improve satiety by preventing major spikes and falls in blood sugar levels. One study showed that low GI foods combined with a moderately high-protein diet was an effective method of weight loss.²

However, pizza, chocolate, and whole milk are on the low GI list, but can be high in calories and lead to weight maintenance or gain in large portions. Consider all aspects of your diet when trying to lose weight.

Easy changes for a lower GI diet pattern

• Breakfast: bran cereal instead of sweetened rice cereal, and whole fruit instead of juice
• Choose an apple for a morning snack with a handful of almonds instead of biscuits
• Lunch: have a burger without a bun and green beans on the side instead of fries
• For an afternoon snack, try a Greek yogurt instead of crisps
• Dinner: replace white rice with quinoa, choose a healthy protein (chicken, salmon), and any steamed vegetable

Remember, including foods that contain protein, fibre, and healthy fats can help slow the digestion of carbohydrates and decrease the impact that moderate or high GI foods might have on your blood sugar if eaten on their own.

Take home message

The glycaemic index can be an excellent tool to help determine the impact that a carbohydrate food will have on your blood sugar. This makes it useful for those with health conditions. Many low GI foods are also very healthy choices — high in fibere, water, vitamins, and minerals. However, the low GI diet should only be a part of a healthy eating pattern. Following just the glycaemic index with no concern of the portion size or calorie content can still lead to weight gain and future health issues.