Eating for Sustained Energy: The Basics of Glycaemic Index and Where FUTURELIFE® Products Fit In.

By: Ashleigh Smith

In this fast paced society it becomes important to make sure that we are not taking short cuts when it comes to healthy eating. Our body uses the food we eat as fuel to ensure it functions at its optimum. Foods and liquids that contain carbohydrates, protein and fat are broken down into smaller components and absorbed into the blood where they are used to perform various functions. Carbohydrates are the main source of fuel within the body, but your body will use protein and fat if carbohydrates are depleted. Not all foods in these groups are created equally; therefore ensuring that you choose foods that provide you with round-the-clock energy is very important.


Carbohydrates come in two types, simple (refined) and complex (unrefined); both are broken down to glucose which is used by our cells as fuel. However, the rate at which these carbohydrates are broken down and absorbed into the blood is important. Complex carbohydrates such as high-fibre cereals, whole-grain breads, pastas, legumes and starchy vegetables, contain fibre which takes longer to breakdown and be absorbed into the blood. Many of these foods are often classified as having a low Glycaemic Index (GI). This results in a more gradual increased in blood glucose resulting in less of a spike in blood sugar and reduced insulin release. As a result you experience prolonged energy, a feeling of satiety and are fuller for longer. Simple or refined carbohydrates have the opposite effect, they are digested quickly provide you with upfront energy however 30 to 60 minutes later you experience a slump. These foods are often are low in fibre, consist of refined carbohydrate and are often high in added sugars. Such foods are classified as high GI, examples include white bread or pasta, pastries, pies, cakes, sweets, chocolate and sugar rich cool drinks.

The Glycaemic Index (GI) is a system that ranks carbohydrate-containing foods based on their physiological effect on blood glucose (blood sugar) levels. The GI of a specific food is determined by comparing the Blood Glucose Response (BGR) of that food with the BGR of glucose.2 Glucose is used as the reference food as it is absorbed quickly from the small intestine and results in the greatest and most rapid rise in blood glucose. Foods are ranked on a scale from 0 – 100, according to their actual effect on blood glucose levels.2

The GI Foundation of South Africa (GIFSA) has developed easily recognisable logos that are displayed on products to show you their GI. In order to display the GIFSA endorsement logo, products are verified by a third party to ensure the product are indeed what it says on the packaging. The table below explains what these logo’s mean:2


GI Range GI foundation logo
Low 55 or less Frequent foods

·         Very low fat

·         Low GI products

·         Ingredients considered to be free of health risks and so may be eaten freely

Eaten often

·         Low fat

·         Low GI products

·         Minimal effect on blood glucose, cholesterol and/or blood pressure levels

·         Ingredients considered to be healthy when eaten in normal amounts

·         Often included with the Diabetes Association logo

Intermediate 56 – 69 Eaten sometimes

·         Intermediate GI

·         Lower fat

·         Safe for those suffering from certain medical conditions, but only in limited servings.

·         Stick to portion size

High 70 or more Eaten with exercise

·         High GI products

·         Although generally unsafe for diabetics, have certain useful applications

·         Excellent for preventing fatigue & boosting energy levels after, or during prolonged strenuous exercise

·         Useful in hypoglycaemia


When it comes to using this concept during meal planning, choosing foods that have a low or intermediate GI will ensure you are consuming more nutritious foods that do not cause spikes in your blood sugar levels. It is okay to sometimes include small quantities of high GI foods in a meal, as long as most of the meal contains lower GI carbohydrate foods such as fruit, vegetables, fruit, legumes, low GI starches and/or dairy.

There are some factors that can influence or change the GI of a food, here they are:

  • The higher the fat, protein and fibre content of a food, the lower the GI becomes. Therefore including lean proteins and small amounts of “good” fats can lower the GI of a meal.
  • As a fruit or vegetable ripens and storage time increases, the higher the GI becomes.
  • Processing of food increases the GI e.g.
    • Fruit juice has a higher GI than the whole fruit.
    • Mashed potato has a higher GI than a whole baked potato.
    • Stone-ground whole-wheat bread has a lower GI than other whole-wheat breads.
  • Cooking method and time e.g.
    • Al dente pasta has a lower GI than soft-cooked pasta.
  • Food eaten alone vs. combined with other foods e.g. when high GI foods are eaten in combination with low GI foods, it results in more balanced blood glucose levels.4

The GI gives you an indication of the type of carbohydrate, but it doesn’t tell you about how much you should be eating therefore portion control is still key. There are also some foods that are classified as being high GI which are nutrient-dense and should not necessarily be excluded. An example of these is certain fruits and starchy vegetables.  While higher GI values are perceived “bad”, the quantity of carbohydrate per serving in these examples is relatively low, therefore the effect on blood sugar levels will be minimal.3


  • Eat at least 3 meals a day and include small snacks if necessary.
  • At meals, include something from each food group as foods high in fibre, protein and fat take a longer time to digest.
    • Include lean cuts of proteins such as chicken, ostrich, fish, pork, and beef, as well as beans, peas, lentils and chickpeas
    • Moderate amounts of healthy monounsaturated and polyunsaturated fats such as avocados, seeds, nuts, omega-3 rich fish and plant oils such as olive, canola, avocado etc…
  • Including at least 2 litres of caffeine, sugar and alcohol free fluids every day. Alcohol is a depressant and can reduce your energy levels, while caffeine usually provides an initial two-hour energy burst, followed by a crash.

At FUTURELIFE® we strive to develop products that are not only convenient but nutritionally dense. Many of our products are low or intermediate GI; the table below gives you an indication of the GI of our products:3




Product Gl range Portion Sizes

(g / ml)

Carbs (g) per portion size
FUTURELIFE® HIGH ENERGY Smart Food™ Low 50 21.5
FUTURELIFE® HIGH PROTEIN Smart Food™ Lowest 50 18
FUTURELIFE® ZERO Smart Food™ Low 40 20
FUTURELIFE® Smart Drink™ Low 250 ml 21
FUTURELIFE® Smart Bread™ (BROWN & WHITE) Low 2 slices 28 – 30
FUTURELIFE® ZERO WITH OATS Intermediate (calculated) 40 22
FUTURELIFE® Crunch Intermediate 40 27
FUTURELIFE® Smart Oats® Intermediate 50 32.5

For more information on GI and which foods are classified into certain categories refer to or chat to your dietician. Visit our website on for nutrition related articles, meal plans or more information on any of our products.