THE TRENDY BATTLE

Every so often, specific diets become trendy, like keto and paleo. It is not uncommon to see people take sides between fats and carbohydrates. Which ones should we eliminate and which ones to consume?
Carbohydrates and fats are the two macronutrients responsible for providing us with energy. Carbohydrates supply four calories per gram, while fats provide nine calories per gram, but that fact alone doesn’t make one better than the other, they just play a different role in our body.

HOW DO CARBOHYDRATES WORK AND WHY SOME PEOPLE AVOID THEM?

KINDS OF CARBS

We must first start by understanding that we consume two kinds of carbohydrates: disaccharides and polysaccharides (better known as simple and complex carbohydrates).

To digest disaccharides, we must break it down into simple sugars (monosaccharides) to be absorbed by the intestine and then converted into glucose by the liver. The glucose gets delivered to the muscles and organs via the bloodstream, to either be utilized as energy or stored in the form of glycogen. The most common examples are sucrose (table sugar), lactose (dairies), and maltose (bread and other food sources).

The body digests polysaccharides more slowly and steadily than disaccharides, making them a better option. As the name indicates, polysaccharides are formed by a chain of several monosaccharides.
The most common examples of polysaccharides are:

 Starch, found in bread, pasta, potatoes, rice, vegetables, etc.

Glycogen, produced by the liver, and stored in the liver and muscles.

 Cellulose, found in plants, which makes it the most abundant organic molecule on earth.

THE “CARB-PHOBIA” EFFECT

Carbohydrates have gained a bad reputation for a reason. Sugar (sucrose) addiction in the USA is a reason for concern. According to the New Hampshire department of health and human services, the average American consumes over 190 grams of sugar a day. Keep in mind that the recommended amount for a 2000 calories diet is 75 grams or less.

Due to their rapid absorption, disaccharides (simple carbohydrates) can overflow the limits of the muscle cells and liver. The excess will be converted and stored as fats. The slow-paced and uniform digestion of the polysaccharides (complex carbohydrates) makes them a more reliable and efficient source of energy.

In the early ’60s, Robert Atkins popularized a low carb/high fat/high protein diet. Later on, in 2017, the keto diet gained the popularity the Atkins diet had lost. Both diets emphasize the extreme limitation of carbohydrate consumption.
Even though the body has limited storage for carbohydrates, satisfying the needs for the maximum glycogen storage guarantees proper bodily function and optimal physical performance, especially for anaerobic activities.

HOW DO FATS WORK AND WHY SOME PEOPLE AVOID THEM?

KINDS OF FATS

Fats are an essential part of a balanced diet. Besides providing the energy for aerobic activities, they bring support to the immune system and other bodily functions. 

    Based on their chemical structure, fats are classified into saturated and unsaturated. Due to the nature of their composition, saturated fats are not easily broken down by the liver. They are processed only partially, which consequently allows for the leftover particles to leave a trace of low-density lipoproteins (LDL) in the bloodstream, better known as bad cholesterol. On the other hand, unsaturated fats are easily processed by the liver. Then they are converted into fatty acids, to be stored in the fat cells, to be later utilized in aerobic activities.
In the presence of low glucose levels (or the inability to utilize the glucose), the liver will convert part of the consumed fat into ketones, which can be utilized for anaerobic activities. That explains why people who suffer from diabetes have an elevated number of ketones in their blood.

THE “FAT-PHOBIA” EFFECT

Comprehensibly, people trying to watch their weight and health, try to reduce or eliminate the consumption of fats. Saturated fats have a direct impact on the levels of LDL, which at the same time increases the risk for heart attacks or strokes. Also, packing nine calories per gram, fats (saturated and unsaturated) are quick to raise the number of calories consumed. 

Unsaturated fats are highly beneficial for our health. They provide vitamin E, which plays a role in the formation of red blood cells and helps with the utilization of vitamin K.

SO, WHAT IS TO BLAME? CARBS OR FATS?

Most questions don’t have a one-line answer; in reality, neither carbs nor fats are to be blamed, but rather overeating. To understand what it means, we need to look at the total caloric intake.

There is a recommended caloric intake to maintain our body weight, which is the same as our total caloric outtake. After that, it all comes down to simple math: we gain weight if we eat more calories than we utilize, and we lose weight if we spend more than we consume. Carbohydrates and fats are both essential for our optimal performance and health.
The USDA recommends 60% of the caloric intake from carbohydrates, but only 1/4 or less of that should be simple carbohydrates (to open the option for fruits and the vitamins they provide), and 20% of the caloric intake from unsaturated fats (the USDA does not recommend saturated fats). Considering that carbohydrates have four calories per gram and fats have nine, that would be equivalent to 300 grams of carbs and 45 grams of fats, in a 2000 calorie diet.
Note: the remaining 20% should come from proteins, which provide 4 calories per gram, even when they are not intended as a source of energy.

STORING THE EXCESS

For survival purposes, the body is equipped with “storage units”. Muscle cells, the liver, and fat cells can store energy in different ways.
The muscle cells and the liver have the capability of storing a limited amount of glycogen, while the fat cells (adipocytes) can store an unlimited quantity of fatty acids. The average human body can store roughly 2000 calories in glycogen. As soon as the body reaches that limit, the glucose will be converted into fatty acids (rather than glycogen) and stored in the fat cells, to be utilized later as fuel for aerobic activities.
The excessive energy digested from fats gets stored directly in the fat cells (also in the form of fatty acids).

Note: Since the adipocytes can adapt to the demands of fat storage (by expanding or contracting), the human body doesn’t need to change the number of fat cells as we gain or lose weight.

RESEARCH BEFORE COMMITTING

There is a wide variety of dietary trends. They are all based on the proportion and source of the macronutrients that determine your caloric intake. Before enrolling in any nutritional regime, take the time to research the function, benefits, recommendations, and consequences of the macronutrients you are planning on eating. Consult with reliable sources, such as the American Heart Association, the Centers for Disease Control and Prevention, the Mayo Clinic, etc.
Remember, publishing a false statement or claims on the internet, requires little effort, and no scientific study to support it.