The Glycemic Index: What it is and How to Use it to Your Advantage
We talk a lot about carbs, but here’s something important to understand: not all carbs affect your body in the same way.
Some cause a rapid spike in blood sugar, followed by a crash that leaves you tired, hungry, and reaching for more food. Others create a slower, more controlled response that helps you stay full and energised.
This is where the Glycemic Index comes in.
What is the Glycemic Index?
The Glycemic Index (GI) is simply a scale from 0 to 100 that measures how quickly a food raises your blood sugar. Foods with a high GI are digested quickly and cause a sharp increase in blood sugar. Low GI foods are digested more slowly, leading to a more gradual rise.
For example, white bread and sugary cereals rank high on the GI scale, while foods like eggs and meat have little to no effect on blood sugar.
In practical terms, this means a bowl of cereal may leave you hungry not long after eating, while a meal of eggs can keep you satisfied for hours without the crash.
It’s a simple concept, but it has a powerful impact on how you feel throughout the day, and how easy it is to stay consistent with your goals.
Why blood sugar matters
Insulin often gets most of the attention when it comes to weight loss and metabolic health, but blood sugar plays an important role, too.
When you eat high GI foods, your blood sugar rises quickly. Your body responds by releasing insulin to bring it back down. But this drop can happen just as fast as the spike. The result is a sudden crash in energy.
This is when hunger returns, even if you recently ate, and cravings start to build. It’s not a lack of discipline, it’s a biological response.
Over time, this creates a repeating cycle: spike, crash, crave, repeat.
Low GI foods, on the other hand, help maintain a more stable blood sugar level. Without the sharp rise and fall, energy remains steady and cravings are far easier to manage.
This is one of the key reasons why whole food approaches, such as Keto and Carnivore, tend to be so effective.
It also makes fasting much more manageable, since stable blood sugar reduces the constant drive to eat.
High GI vs. low GI foods
High GI foods are typically processed carbohydrates and sugars. This includes bread, pasta, cereals, pastries, and most packaged snacks. These foods are broken down quickly and enter the bloodstream almost immediately.
Low GI foods are generally whole, nutrient-dense options, such as meat, eggs, healthy fats, and low carb vegetables and fruits. These take longer to digest and provide a more sustained source of energy.
And another important factor is that fat and protein slow digestion. When included in a meal, they help reduce the overall blood sugar response.
How to use the GI scale to your advantage
If you’re new to the Glycemic Index, you can easily look up foods and compare where they fall on the scale. Choosing lower GI options more often is a simple way to improve energy levels and reduce cravings.
If you’re already following a Keto or Carnivore approach, you’re naturally eating on the lower end of the GI scale.
However, sometimes there are situations like social events or family dinners where you step outside your usual routine. In those moments, the GI can help guide better choices.
For example, if you want to include fruit but avoid a major blood sugar spike, you can compare options. A pear has a lower GI than a peach, making it the more stable choice.
Keep it simple
You don’t need to memorise numbers or overanalyse every meal.
The Glycemic Index is simply a tool, not a rulebook. If you focus on real foods, prioritise protein and healthy fats, and limit processed carbohydrates, you’re already using the GI to your advantage.
