A banana contains sugar. Oats contain carbohydrates. Bread raises blood glucose. All three sentences are true, and yet they tell us almost nothing about whether a given breakfast is any good. Modern wellness adores one number that promises to resolve that problem: the glycemic index.
The glycemic index, or GI, describes how quickly a carbohydrate-containing food raises blood glucose concentration compared to a reference food — most often pure glucose. Foods with a higher GI produce a faster and larger glucose response in a standardised test; those with a lower GI produce a slower and smaller one.
That is useful information. The trouble begins when we translate it as high GI = bad food, low GI = good food.
GI is measured after a portion containing a standardised amount of available carbohydrates, not after the portion one would necessarily eat in real life. Watermelon is the classic example: its GI can be relatively high, but a typical serving contains a great deal of water and relatively few carbohydrates. Hence the concept of glycemic load, which factors in how many carbohydrates are actually consumed.
More importantly, we rarely eat a single food in isolation.
Oats can end up in a bowl with fruit, nuts, seeds, and a protein source. Bread can be part of a meal with eggs, avocado, and vegetables. Protein, fat, fibre, food structure, and processing method can all alter the speed of digestion and the postprandial response. The GI of one component is therefore not the same as the glycemic response to an entire breakfast.
Nor do two people necessarily respond identically. A large study published in Cell demonstrated significant individual variation in postprandial responses to the same foods. Sleep, the previous meal, physical activity, metabolic health, and meal composition can all shift what happens after eating. That does not make GI useless; it means the human metabolism is not a single-column table.
And then came continuous glucose monitors.
Devices developed as a vital tool for people with diabetes crossed into the wellness world, where healthy individuals can now watch every glucose fluctuation in real time. This is interesting and can teach us something about our own habits. But it has also created a new kind of anxiety: the idea that every postprandial glucose rise is a problem to be flattened.
It is not.
Glucose is supposed to rise after eating carbohydrates. Insulin then helps glucose to be used and stored. That is normal physiology, not a malfunction. In a healthy person, the goal is not to make the graph line look like a flat sea. What matters far more is the long-term picture: diet quality, total energy intake, physical activity, sleep, and metabolic health.
This does not mean the postprandial response is unimportant. A diet heavy in refined carbohydrates, low in fibre, and high in added sugar can be part of a poor pattern. In diabetes and pre-diabetes, glucose control becomes particularly significant and individual recommendations should be developed with a doctor or dietitian. But a healthy person does not need to fear a mango because a sensor drew a hill.
The most useful part of the GI story is therefore not prohibition — it is context.
Choose carbohydrates that come with fibre and are less processed more often. Pair them with protein, fats, vegetables, nuts, or seeds when it makes sense for a meal. Not because every glucose spike must be hacked, but because such a meal typically delivers more nutrients, better satiety, and slower digestion.
That is also why at VERA we are more interested in the construction of the whole plate than in the low-GI label. Avocado, eggs, vegetables, oats, granola, fruit, and bread can be part of very different meals depending on how they are combined. One number cannot replace that conversation.
The glycemic index is a tool. A good tool, when used for the questions it can actually answer.
The only problem is that we keep trying to make a hammer into a nutritionist.
Try it at VERA — specialty café and wellness bistro, Nikole Spasića 4, Stari Grad, Belgrade.
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