How many carbohydrates should I eat?

December 24, 2021

¿Qué cantidad de carbohidratos tengo que comer?

It seems that carbohydrates are now demonized by many, and today I do not want to write an article telling you what you have to do, but rather explain certain important concepts of basic physiology so that you can draw your own conclusions.

When we consume food we obtain “energy” thanks to 3 main macronutrients: proteins, carbohydrates and fats.

Ideally we are interested in using fat (also called lipids) and carbohydrates (also called carbohydrates) as a source of energy, since proteins are the last resource and we are interested in proteins serving for tissue regeneration, production of enzymes and other molecules. important and not as an energy source.

Let's understand what carbohydrates are

Carbohydrates are sugar molecules: when we eat bread, pasta or fruit our body breaks down these carbohydrates into glucose molecules during the digestive process so we can absorb and use them.

This glucose, or blood sugar, is the main source of energy for the body's cells, tissues and organs. When it reaches the blood once absorbed through the small intestine, our pancreas secretes insulin that causes the cells to express (place in their membranes) a receptor called GLUT (there are several types), a kind of gate to be able to absorb this sugar that circulates through our blood. Once it enters the cell, through certain enzymatic processes it will be converted into pyruvate, then acetyl-CoA and finally it will enter our mitochondria, present in all the cells of the body.

Here the Citric Acid cycle or Krebs Cycle begins, where this Acetyl-CoA molecule will go through certain transformation processes, producing ATP, NADH and FADH as the final product, and our cells will now have sufficient energy.

And the fats?

Well, when they are absorbed largely thanks to the bile emulsion produced by the liver and pancreatic enzymes, they are absorbed in the small intestine, transported by chylomicrons and broken down into fatty acids and glycerol. The short chain can easily enter the mitochondria, the long chain must be introduced by Acyl-CoA, whose action requires the presence of Carnitine. Once inside the mitochondria, the fatty acids will fragment and shorten, producing acetyls suitable for use in the Krebs cycle. The process is called beta-oxidation of fatty acids.

That is, from the two substrates our body can produce ATP, the energy molecule with which our cells can function.

And here comes the problem…. Can we absorb all the carbohydrates and fats we eat? What happens if we are constantly giving food?

Well logically our body is intelligent. We are able to store excess glucose in the liver (100–120 grams) and in the muscle (15 to 25g per kg of muscle mass), this is what we call glycogen. When these deposits are full, this excess blood glucose is stored in the form of fat, which we call adipose tissue, just like when we consume excess fat. Think... if our cells absorb all the carbohydrates or fats we eat without limit, we would die!

What happens if we have high blood glucose levels?

The current problem is that we have a greatly reduced energy EXPENDITURE, a society with a muscle mass that is conspicuous by its absence and we have a high consumption of carbohydrates, energy that we do not need and cannot manage. When we are having high blood sugar levels, this causes us to be very dependent on carbohydrates, we are unable to fast, we are in an inflammatory state, we have a hard time losing weight, dry mouth, blurred vision or recurrent infections, among others.

Think that when you eat carbohydrates your pancreas has to secrete insulin so that your cells can absorb that glucose, but there comes a point where if you consume too many carbohydrates and do not expend enough energy, your cells become resistant to insulin. , “they close the floodgates” and are unable to absorb that glucose to protect us. In the long term, your pancreas will try to secrete more insulin to the point where it is exhausted and does not produce enough insulin, ending in type 2 diabetes.

On the other hand, we must remember that a high-fat diet rich in palmitic acid, an SFA, is associated with lower insulin sensitivity and can also increase atherosclerosis parameters. Not only carbohydrates harm us, but other types of fat can contribute to insulin resistance and type 2 diabetes.

Given this information, how many carbohydrates do I need?

When we read this information, we get scared and think that we will end up being diabetic. However, if you are a person who exercises, is active, and has a healthy lifestyle, this will not be your case. Your muscle mass will tolerate a greater amount of glucose and will manage it much better than someone who is obese and sedentary because you expend energy and your cells are receptive, they need energy. So how many grams of carbohydrates do I need? I put you in 4 situations:

  • Obese people who do not exercise properly: we recommend a low consumption of carbohydrates (25 to 50g per day), a moderate/high consumption of protein (1.2/1.4g per kg of weight) and a high consumption of healthy fats . We will avoid carbohydrates at night because insulin synthesis is lower. 
  • Obese people who train crossfit/endurance/weights: we recommend a consumption of 50/125g of carbohydrates, a moderate/high consumption of protein (1,2,1,6g per kg of weight) and a moderate consumption of healthy fats. If we have metabolic problems with prediabetes, we do recommend a consumption of 25 to 50g per day. We will avoid carbohydrates at night because insulin synthesis is lower.
  • People with a correct weight but who do not exercise: we recommend a low carb consumption of 25-50g of carbohydrates per day, a moderate/high protein diet (1.2/1.4g per kg of weight) and a moderate consumption of fats.
  • People with a correct weight and who train crossfit/endurance/weights: a consumption of 150/250gr of carbohydrates per day (in the case of weights 50-125gr day, a high consumption of proteins (1.6/2gr per kg of weight) and moderate fat consumption.

The secret is to consume the appropriate amount according to your caloric expenditure and muscle mass. You don't have to be afraid of carbohydrates, but rather consume the right amount for you. I have to make a note that there are people who feel more comfortable on low carb, and we can exercise and gain muscle mass being on low carb if we consume more than we spend, however it is not optimal for gaining muscle mass, and personally in Athlete people do not see it as optimal at all to be on a ketogenic diet permanently.

I leave you some tricks:

  • You can calculate the amount of carbohydrates with applications like My Fitnesspal, not so that you always weigh everything you eat, but so that you get an idea of ​​the amount you need based on the exercise you do.
  • On rest days, take the opportunity to reduce carbohydrates and consume more fats and on days of greater physical expenditure the other way around. 
  • Do strength training at least 3 days a week combined with cardiovascular exercise such as walking, HIT, dancing, running 2 or 3 days a week, this will help us stay metabolically healthy. 

I hope it has helped you and do not hesitate to share it with people who need this information.

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If you need a personalized plan and to resolve your doubts about how to structure your diet individually, request your appointment here .

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