Why a fatty diet is better for the lungs and overall energy of a person.

The predominant macronutrient in the diet affects respiration, tissue oxygen saturation, lung function, and even the subjective feeling of vitality.

Carbohydrates

During the complete oxidation of glucose (the main carbohydrate), the following reaction occurs:

C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + energy (ATP)

This means:

• 6 molecules of oxygen (O₂) are consumed,
• 6 molecules of carbon dioxide (CO₂) are released,
• The ratio CO₂ / O₂ = 1.0 — this is called the respiratory quotient (RQ).

The lungs receive oxygen exactly in the volume that is then released as carbon dioxide. This does not create an excess of oxygen in the tissues.

Fats

During the oxidation of, for example, palmitic acid (one of the common fatty acids), the reaction looks like this:

C₁₆H₃₂O₂ + 23 O₂ → 16 CO₂ + 16 H₂O + energy (ATP)

What we see:

• 23 molecules of oxygen are consumed,
• only 16 molecules of CO₂ are released,
• The respiratory quotient RQ ≈ 0.7.

For each molecule of oxygen, there is less carbon dioxide produced — in other words, oxygen "remains" in the body longer or is used differently than just for the formation of CO₂.

What happens to this "excess" oxygen?

The body does not produce oxygen, but during fat metabolism, more oxygen is consumed than CO₂ is released. This excess:

• Is used in the mitochondria to form water (H₂O) in the final phase of the respiratory chain;
• Dissolves in blood plasma and tissues, increasing saturation;
• Increases the partial pressure of oxygen in the alveoli;
• Improves ventilation and perfusion of the lungs, especially in the lower regions.

Impact on the lung surfactant complex

Surfactant is a lipid-protein film produced by alveolar type II pneumocytes. Its main function is to reduce surface tension in the alveoli, preventing their collapse during exhalation.

A diet focused on fats supports and stimulates the surfactant system:

• Fatty acids and choline are raw materials for surfactant;
• Increased oxygen content in the alveoli improves its distribution across the lung surface;
• Deep breathing during fat metabolism contributes to the mechanical expansion of alveoli and activation of pneumocytes.

Thus, fat metabolism improves the conditions for stable lung function, making breathing more economical and efficient.

Conclusion

The oxidation of fats is not just "another source of energy." It is a holistic metabolic mode that:

• reduces carbon dioxide release,
• improves lung ventilation,
• activates the surfactant complex,
• and supports a stable, oxygen-saturated energy supply for the body.