What Is The Low-Glycemic Diet?

What Is The Low-Glycemic Diet?

The low-glycemic diet is one that splits opinion.

Research has shown it can be extremely effective in aiding weight loss and lowering blood sugar levels, but it has been criticised for ranking foods in a way that ignores their overall nutrient value.

Here’s a look at what the low-glycemic diet is and how you can follow it.

The Glycemic Index

The diet centres around the glycemic index (GI) which ranks foods containing carbohydrates on how they affect blood sugar levels.

Different types of carbohydrate affect blood sugar to a lesser or greater extent, and this is what the GI measures.

All foods are given a score based on how much they elevate sugar levels in comparison to 50g of pure glucose, which has a GI rating of 100. A score below 55 is considered low, while 56-69 is medium and 70 or above is high.

Foods that do not contain carbohydrates, such as meat or fish, are not given a score.

The Glycemic Load

How much a type of carbohydrate affects blood sugar depends on a number of factors, including its starch structure and how it was cooked, but obviously the quantity consumed will also play a role.

This is where the glycemic load rating (GL), which measures both the type of carb (GI) and the quantity in grams, comes in.

A low GL rating would be 10 or below, a medium rating between 11 and 19, and a high rating 20 or above.

Adults are recommended to keep their GL daily score below 100 in order to keep their blood sugar levels in check, and a database can be used to look up the value of various foods.


While a low-glycemic diet has been associated with weight loss, reduced risk of heart disease and lower cholesterol levels, it does sometimes rank foods in seemingly illogical orders.

The best example is the comparison of french fries and a baked potato. Despite the later being the healthier option, french fries would be more favourable to someone looking to restrict their GI intake as they have a rating of 75 compared to the potato’s 85.