The Gi Guide - How will it work for me?

The Gi rating of a food is important to nutrition and health because:

• low Gi foods tend to have more nutritional content than the high Gi foods, which are usually highly processed. This is important for your health.

• low Gi foods break down in your digestive system more slowly, leaving you feeling more satiated for a longer period of time so you don’t go hungry. This is critical for weight control.

• low Gi foods are important for managing diseases, such as diabetes where controlling blood sugar levels is essential.

Let’s deal with each of these in turn:

Nutrition
High Gi foods are in general all highly processed where most of the original fibre and nutrients have been stripped away. Conversely most low Gi foods are more in their natural state with their nutritional benefits intact.

If there is one thing that nutritionists and medical profession agree upon, it is that diets rich in fruits, vegetables, whole grains, legumes and low-fat dairy foods are essential for good health. All these foods are low Gi.

Weight control
High Gi foods such as sugary breakfast cereals digest quickly and by mid-morning you are hungry again and looking for your next sugar fix. Conversely, take breakfast traditional porridge oats, the sort many of us haven’t had since we were kids. Porridge is low Gi and digests more slowly in your tummy so you are not hungry by the time you get to work.

Low Gi foods leave you feeling fuller for longer, and enable you to control your appetite and therefore your weight.

Diabetes
Because low Gi foods break down more slowly, it means that the supply of glucose into the bloodstream is more gradual and therefore helps moderate blood sugar levels. The Canadian Diabetes Association recently selected Rick Gallop’s book The Gi Diet as the diet of choice amongst today’s leading diets.

What affects the Gi of foods?

The role of protein and fat
Though the Gi is based on carbohydrates, it is also profoundly influenced by protein and fat, both of which act as brakes on your digestive system. Most carbohydrate-based foods also contain both fats and proteins. For instance, some vegetables such as corn are a good source of oils, and beans a good source of protein. Also when we eat a meal we are usually combining all three food categories in our stomach.

So a combination of low Gi carbohydrates, low-fat proteins and good fats/oils are the ideal combination of foods for a healthy and nutritious diet.

Fibre
Fibre comes in two forms:

• Soluble or viscous fibre which is soluble in water, thickens food, thus slowing down its passage through your digestive tract.

• Insoluble fibre acts as a physical barrier to the digestive enzymes and again slows down the digestive process.

That is one reason why foods high in viscous fibre such as fruits, oats and beans are low Gi foods. Foods such as 100% bran breakfast cereals and whole grains are high in insoluble fibre and are again low Gi.

Impact of cooking and processing
Any processing of food will raise the Gi, because processing, usually cooking, is the first step in breaking down food into glucose. This is, in effect, digestion taking place outside your body. For instance, if you have ever had the misfortune to eat a raw potato, you will know that it is almost indigestible and tummy ache is virtually guaranteed.

On the other hand, if you eat a baked potato, which is high Gi, it digests extremely quickly. In this case the cooking process is the only variable and demonstrates how cooking starts breaking down the starch capsules and fibre, making it easier for your digestive juices to get to work. So when you are cooking foods, especially vegetables, slightly undercook them. This will both help to reduce the loss of vitamins and other essential nutrients as well as keep the Gi low.

One other popular food that you should undercook is pasta. Italians call this al dente or ‘to the bite’. This not only tastes better, but also helps keep the Gi lower.

Tinned food products, have been subjected to very high temperatures in the canning process to avoid spoilage. Tinned soups are a good example. A tin of soup can sometimes have double the Gi when compared to a homemade soup prepared from scratch. While it is sometimes more convenient to use tinned products, especially if you are under time pressure, try to keep these to a minimum and use fresh, dried, or frozen products in preference.

Letting your body do the processing is another good reason for always eating the fruit rather than drinking its juice. This way you ensure you’re getting all the full benefits, especially fibre, from the fruit rather than buying its highly processed juice. You will also be consuming fewer calories: a glass of orange juice for instance contains nearly two and a half times the calories of a fresh orange.

Rice and potatoes
Rice and potatoes are two staples that have unusual Gi characteristics. They are two of the few foods that have different Gi ratings dependent on the type used.

With rice, you should preferably use long grain or basmati rice rather than the short grain (glutinous/sticky) variety frequently found in Chinese food. The Gi of the latter can be higher by 50% or more. Potatoes also have a broad Gi range. Your best choice is boiled small new potatoes and your worst choices are large baked potatoes and chips. Do not mash potatoes as this also raises the Gi by breaking them down before eating. Remember; let your body do the processing.