You’ve more than likely been told at some point that you should eat brown rice over white rice, or sweet potato over white potato. If you’re wondering why this is, the reason ‘boils down’ to their positioning on the GI scale.

The GI (Glycemic Index) Scale categorises food by the rate at which glucose enters the blood stream.

The faster it enters the bloodstream, the higher the GI.

The slower it enters the bloodstream, the lower the GI.

Sounds pretty simple, right?

For example, pure glucose is known to digest and increase blood sugars very rapidly, whereas oats take longer to digest and enter the blood stream.

Hence glucose scores a perfect 100 (high) on the GI scale, whereas oats score at 49 (low-mod).

However, the GI scale is only applicable if the food is consumed in isolation. As soon as it is consumed with other foods and ingredients, the GI scale becomes irrelevant and inaccurate.

Chances are that you aren’t going to be eating many of these foods in isolation and are almost always going to eat them as part of a meal containing protein, fats and fibre too.

This effectively renders the scale obsolete, and within instances like these it’s usually best to go with your gut instinct – that being choose what your gut will prefer! Ultimately, your adherence to a nutritional regime is often the key to it being a success or failure.

Don’t force yourself to eat a food you dislike just because of it’s positioning on the GI scale, especially if eating this as part of a larger meal. As long as you’re eating a mixed meal containing all macro-nutrients, the food that you enjoy should take preference over where a carbohydrate sits on a scale.

A Caveat

There is a caveat to all of the above, and really this comes down to relatively advanced trainees that know their bodies and are pushing the extremes at either end of the body composition spectrum (caloric excess or caloric deficit).

There are certain situations in which specific scaling GI foods are favoured.

For example, if someone is trying to add muscle and eat multiple times a day but are struggling with getting the calories in due to poor appetite, certain foods that are high in GI are better for you. This is because they lack in fibre and are far easier to digest than foods lower in GI, making them easier to eat and leaving you feeling less bloated. An example here is for our muscle builders really pushing the envelope, we’re fans of cereals such as Coco Pops or Rice Krispies, owing to the ability to get lots of carbohydrates in a quick window, yet with little to no digestive issues.

On the opposite end of the spectrum, someone that is higher in body fat and is on reduced calories will be hungrier by the time their meals come around. In this instance, they would need a food that is lower in GI as it would take longer to eat and digest and contain more fibre, and so would keep them feeling fuller for longer. Here is when traditional dieting foods like oats and sweet potato may be of use.

Certainly, knowing your GI scale can be beneficial in certain circumstances, but if food is consumed as part of a meal, it makes no real difference. What to take away from this is that, unless you are dieting at extreme ends of the scale, you should go by hunger and taste preference. Ultimately, if you’re eating foods that you don’t enjoy, you’re less likely to adhere to the diet.

Stick to what you like, and the next time someone tells you to eat brown rice over white, now you know the "GI-st" of it.