What happens when we eat sugar?

31 MARCH 2017

Encouraged by how successful my last post on food was with you all, where I shared my concerns about organic food and the knowledge of the nutritionist Mª Antonia Rodríguez, today we are back with a thorny topic: sugar.

When we talk about table sugar, or sucrose, which is the same thing, we are referring to white sugar. It is an empty-calorie food. In other words, it lacks fibre, vitamins, minerals and any other nutrient. But we don’t only find sugar in sucrose. It is also naturally present in many foods. The list is very long, beginning with carbohydrates (fruit, vegetables, cereals…) and dairy products, whose sugar is known as lactose, and includes many alcoholic drinks.


Humans obtain energy from fats, proteins and sugars. The latter, when ingested, travel to the liver and are turned into glucose, one of the fuels for our organism. The crux of the matter is how our body reacts, depending on the origin of this glucose and its glycaemic index.

The glycaemic index (GI) of a food is its ability to increase the glucose circulating in the blood. This index will determine the secretion of insulin, a hormone secreted by the pancreas. This organ is responsible for ensuring that the glucose contained in the blood can penetrate the tissues of our body and be transformed into energy.

The higher a food’s GI, the higher the insulin spike. The high insulin spikes caused by sugar do not provide us with more energy; in fact, they do the opposite. They cause a very fleeting energy boost, which can mean that the brain does not receive the sensation of being full, and consequently, a short time later we feel the need to eat again. And not only that, the glucose that is not used as energy is converted into fat reserves, gathering not only on our hips or abdomen, but also in the walls of our arteries. This can help us to understand the many diseases that are caused by consuming too much sugar…

Among the foods with a high GI are carbohydrates. But don’t panic! You do not have to stop eating carbohydrates. Why? Because, in addition to vitamins and minerals, they contain marvellous fibre, which means that the GI is reduced, as if by magic. They neutralise the “insulin spike” and ensure that the energy we consume is distributed gradually and over a longer period of time. However, we do have to bear in mind that not all carbohydrates are assimilated in the same way. Refined carbohydrates act like sugar because they do not contain fibre. That is why it is so important to make sure that the carbohydrates we eat are 100% wholegrain.

We have added a list of foods and their GI to serve as a reference when you are choosing your food.

GI – Food
100  Glucose (we do not eat pure glucose, but we are using the index as a reference)
90    Cooked carrots
80    Honey (although it contains minerals and vitamins, it is pure sugar)
70    White sugar, white bread, white rice, pastries, cooked potatoes
60    Wholegrain rice, banana, cakes
50    Crisps, pasta, orange juice
45    Grapes
40    Orange, apple, peach, pear
35    Wholegrain bread, full fat milk, yogurt, coconut sugar
32    Cherries, acacia honey
30    Wholegrain pasta, chickpeas, lentils, raw carrot
20    Fructose
15    Vegetables
14    Peanut
11    Agave
0     Stevia

I try to avoid the high insulin spikes caused by foods with little nutritional value, and be aware of where the glucose I consume comes from to balance out my menus. For example, in a large evening meal, I choose either wine or dessert, because I know that both of them will give my body too much sugar. It is interesting how when you understand that what is happening inside your body depends on what you eat, you become much more aware of your food and it is easier to avoid vicious circles.

I am sharing an example given to me by Mª Antonia, which helped me to understand an even more complex concept: if you eat fat with sugar, the fat is dragged by the insulin spike and is directly turned into fat reserves, and not only into calories that we use as fuel, as would normally occur. For example, when we eat an egg flan, the fat from the yolk is added to the fat reserves by the insulin secretion triggered by the sugar in the recipe. If for example, we replace the sugar with a natural sweetener like stevia, with a GI of 0, this effect does not occur (in another post we will discuss natural alternatives to sweeten our meals). It is really important to be able to benefit from the nutrients of the good fats and keep them away from sugars.

Maybe because the explanation of why our body functions the way it does is complex, we find it hard to internalise these essential and necessary concepts that help us to nourish ourselves better. We hope that we have shared the information in a simple and easy-to-understand way. If you want to find out more, or if you have doubts, please leave your question in the comments section of this post. I will answer your questions with the nutritionist Mª Antonia in a video that you will soon find on my YouTube channel. Subscribe if you want to improve your eating habits and wellbeing.


Update –  You can now watch the video where we answer all your questions in the new post.








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Tajna 2 April, 2017

Thanks so much for this post Vanesa ! It’s really important to avoid processed sugar but actually I had no idea that cooked carrots converted into sugar. I always have avoided raw carrot juice. I don’t use honey that often, I prefer to use maple syrup or just one Medjool date to sweeten raw chocolate.
I thought I grew up eating healthfully as my mother wouldn’t allow my sister and I sodas and sugar as well as fast food. But she did allow us to have Tiger Milk bars which are full of high fructose corn syrup. I only found this out as an adult and my mother failed to check the ingredients herself so she had no way of knowing. Now whenever I have “regular chocolate” made with white sugar or even cane sugar I feel it right away and I don’t like it at all. The book “Model Chocolate” by Abigail O’Neill has many recipes for making raw chocolate desserts without sugar is my go to for sweets now. That book sort of saved my life in terms of chocolate, as I knew how unhealthy regular store bought chocolate is but didn’t know how to make it myself.

Thank you for letting me write this and here is Abigail’s book if you ( or anyone ) is interested.


vanesalorenzo 25 April, 2017

Hello Tajna,
Thank you for sharing your experience and your advice. It´s fantastic to read your comment and see how so many of us are more and more interested in finding our own away to bring healthiness in our lives.
Lots of love,

Vanessa 3 April, 2017

Hi Vanessa. I love your blog! I guess I feel a connection to you since I was raised in Spain and moved to new York two years ago. For me, it has been quite an experience having to change my habits ( including my eating) from Spanish food to American. Ever since I moved here I have terrible trouble sleeping. I try having a glass of wine to relax but it doesn’t work. Do you have any recommendations? Thanks!

vanesalorenzo 25 April, 2017

Hello Vanessa,
I totally understand what you are talking about. Spanish eating habits are very different from the US´s. Let me give you an advise about sleeping. Alcohol has lots of calories and it is energy that you would need to burn, so that wine might make you sleepy but will never help you to have a very good night’s sleep.
It´s hard for me to give you an advise without knowing your evening routine. I try to have an early dinner with food easy to digest in order to have a very rested night. Also I leave my iPhone outside of my bedroom.
I hope this helps you.
Lots of love,

What happens when we eat sugar? Encouraged by how successful my last post on food was with you all, where I shared my concerns about organic food and the knowledge of the nutritionist Mª Antonia Rodríguez, today we are back with a thorny topic: sugar. When we talk about table sugar, or sucrose, which is the same thing, we are referring […] http://www.vanesalorenzo.com/en/2017/03/what-happens-when-we-eat-sugar/ Encouraged by how successful my last post on food was with you all, where I shared my concerns about organic food... https://tinyurl.com/y2dz6mgs http://www.vanesalorenzo.com/en/2017/03/what-happens-when-we-eat-sugar/