Glycaemic index and glycaemic load - Why you store fat faster with certain foods

Glycaemic index and glycaemic load

Do carbohydrates make you fat?

No, not really. However, you do need to be a bit savvy when it comes to your consumption of carbohydrates. Our article on carbohydrates explains all about their tasks and structure. Whether you are on a low-carb or high-carb diet, an important aspect of carbohydrate consumption is the glycaemic index and the glycaemic load. In this article we will explain what these terms mean and how they can help you stay slim and fit.

The glycaemic index

upfit nutrition glycaemic index

The glycaemic index (also abbreviated as GI) describes the effect of the carbohydrates in a food on your blood sugar level. The prime example of this is glucose. If you eat pure glucose, your blood sugar levels rise very quickly. The reason for this is that the digestive tract does not have to do any work to break down glucose into its constituent parts, glucose being the smallest unit. The higher the glycaemic index of foods, the faster they are digested and the faster the blood sugar level rises. The hormone insulin is then released. Insulin ensures that the blood sugar level is lowered by activating glucose transporters that bring the sugar from the blood into the body cells. After a rapid rise in blood sugar levels, they fall again almost as quickly, because the body releases insulin proportional to the rise in blood sugar.


A high glycaemic index can lead to food cravings

We then often satisfy the craving with quickly digestible carbohydrates. Our body recognises a lack of energy as the blood sugar level falls and wants to compensate for it quickly. This results in a further release of insulin. However, this cycle is not only problematic because it constantly generates new cravings, but also because the increased insulin secretion inhibits the breakdown of fat. As described above, insulin brings glucose into the cells and the body cannot get stored energy out of the cells simultaneously. Therefore it has to rely on the energy already in the circulation.

Calculate the glycaemic index

The glycemic index is given as a percentage without the percent sign

Pure glucose is the reference value of the glycemic index and has a GI of 100 or 100%. The value indicates the time and the level at which the blood sugar level rises after eating 50 g of carbohydrates. This is then compared with the value of 50 g of glucose. Foods with a glycaemic index above 70 will cause your blood sugar level to rise rapidly. A glycaemic index below 55, on the other hand, means a moderate increase and therefore a low insulin release.

What matters is the level

So it is not only the content of carbohydrates in food that is important, but how quickly they can be converted into glucose in the body. A white bread baguette consists of simple carbohydrates that are quickly absorbed into the bloodstream and has a glycemic index of 95. Wholemeal bread contains the same amount of carbohydrates, but these are less quickly absorbed into the bloodstream, which is why it has a glycaemic index of 58. When you eat wholemeal bread, your body receives complex carbohydrates, which cause your blood sugar level to rise slowly and fall again slowly. Fats, oils and meat alone have a very low glycaemic index. However, be sure to keep an eye on your insulin index if you combine these foods with carbohydrates. This measures the amount of insulin released by a food and this is where meat and fat score high.

The problem with the calculation

The glycaemic index measures how quickly the carbohydrates in a food cause the blood sugar level to rise. The insulin index, on the other hand, measures how strongly insulin is released after the consumption of a food. So what does this help in practice? It is difficult to be guided solely by the glycaemic index of carbohydrates in a food. It is more important to know how many carbohydrates, with which glycaemic index, are contained in a normal portion. Carrots, for example, have a high glycaemic index, but you would have to eat 800 g of them to consume 50 g of carbohydrates. White bread has the same high glycaemic index, but you only need to eat a little more than 100g of it to consume 50g of carbohydrates. The glycaemic index alone is therefore too imprecise to be used effectively.

The glycaemic index of sugar

Glucose has a glycemic index of 100, maltose (maltose) has a glycemic index of 110. Sucrose (household sugar) has a glycemic index of 70. If you do not want to give up sweets but want to keep your blood sugar level low, use sweeteners and sugar alcohols in moderation. Sweeteners such as aspartame and acesulfame-K have no effect on blood sugar levels and therefore have a glycaemic index of 0. Sugar alcohols such as erythritol, xylitol and sorbitol have a low glycaemic index of 9 to 13.

The glycaemic load

For this reason, the glycemic load of a food was calculated. It calculates the type and quantity of carbohydrates in a food. To calculate the glycaemic load, the glycaemic index is used and then applied to the amount of carbohydrates actually consumed. Calculating the glycemic load of carrots gives a much lower value. Carrots only have about 5 g of carbohydrates per 100 g. The effect of carrots on blood sugar levels is therefore very small due to the small amount of sugar that enters the body, even though this amount is quickly metabolized.

An example of how to calculate the formula for the glycaemic load: 1 slice of white bread (GI = 73%) contains 14 g of carbohydrates: GL = 0.73 x 14 = 10.2

Glycaemic index vs. glycaemic load: Which is superior?

glycaemic index vs glycaemic load
Laboratory value More realistic value
Measures the blood sugar response to 50 g of carbohydrates in a food Measures the blood sugar response to the amount of carbohydrate per serving of a food
Method of preparation is not taken into account Preparation method is taken into account
Degree of processing is not taken into account Degree of processing is included in the calculation
Combination with other foods is not taken into account Combination with other food influences value
Water and fibre content influence value
Example: cooked carrots have a glycaemic index of 34 Example: 100 g cooked carrots have a glycemic load of 2

Losing weight with the glycemic index

glycaemic index and weight loss

If you want to lose weight or define your body, i.e. reduce your body fat percentage, choose foods with a low glycemic load and a low glycemic index.

Muscle building with the glycemic index

upfit nutrition glycaemic index and muscle building

A high glycaemic index can also be useful for you.

  • During endurance sports, weight training and muscle building, foods with a high GI ensure that energy is quickly available and your glucose stores are quickly replenished.
  • They enter the bloodstream more quickly and can therefore be used to produce energy more quickly than foods with a low glycemic index.
  • After intensive sport, sugar goes to the muscles not to the fat reserves. This is particularly beneficial if you want to build up muscles through strength training, because in this case the carbohydrates enhance the muscle growth stimulus.

Does a low glycemic index protect your health?

A high or low glycaemic index not only impacts your weight loss and muscle growth, but also your health.

  • Foods with a low glycaemic index and low glycaemic load usually contain more fibre and nutrients because they are less processed. So they provide you with important nutrients. (Tip: You can easily determine your optimal nutrient requirements with our BMI calculator)
  • Studies have shown that frequent consumption of foods with a high glycemic index is more likely to lead to a higher calorie intake, more frequent snacking, obesity and even skin problems like acne.
  • In the worst case, frequent consumption of foods with a high glycaemic index can lead to insulin resistance and thus to diseases such as type 1 and type 2 diabetes.
  • On the other hand, a diet with a predominantly low glycaemic index has a positive effect on these diseases. It also prevents future insulin resistance.

How much should you eat to lose weight?

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Carbohydrates are not bad per se – they can actually help you in reaching your goal. If you want to lose fat and are in the mood for pasta or rice, choose wholemeal spaghetti or brown rice. Remember that frozen or fresh fruit and vegetables are always better than their canned relatives and spike your blood sugar level less than a slice of normal toast.

If, however, you require the opposite effect and want to get fast carbohydrates, then choose foods with a high glycemic index and glycemic load.

Frequently asked questions and answers

The glycaemic index is a numerical value that indicates the level of your blood sugar after eating carbohydrate-rich foods. A glycaemic index above 70 means that your blood sugar level will rise high. Foods with a value of less than 55 will not cause your blood sugar level to rise high.

The glycaemic load is more accurate. Unlike the glycaemic index, the glycaemic load tells you how high your blood sugar levels will rise when you eat a portion of a food. The glycaemic index shows you the increase regardless of the portion, preparation or combination with other foods.

A low glycaemic index and a low glycaemic load will help you lose weight, as foods with a low glycaemic index will cause less or no cravings and provide you with long-term energy. They are also usually more unprocessed, which means they contain more nutrients and fibre. However, a high value can also be useful, for example during endurance sports and when replenishing your carbohydrate reserves after exercise, as it tells you which foods will provide you with energy quickly.

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