Macronutrients: protein, fat, and carbohydrates
Nutrition Foundation Pillar
Protein, fat, and carbohydrates: these are the three macronutrients that make up our diet. They’re often pitted against each other—especially carbohydrates and fat—but all three are essential. Understanding what each one does in your body is better than demonizing any one of them.
Three macros, three roles
All of them provide energy: fat releases 9 kcal per gram, while proteins and carbohydrates release 4 kcal per gram. But their role goes far beyond simply providing fuel.
Proteins are made up of amino acids (nine of which are considered essential because the body cannot produce them). They form enzymes, cellular and muscular structures (actin and myosin, which are responsible for contraction), and transport channels.
Fat makes up the membranes of all your cells, insulates and protects them, and serves as a precursor to signaling molecules that regulate inflammation, among other things.
Carbohydrates are the brain’s and muscles’ preferred direct source of fuel. Fiber, on the other hand, nourishes the gut microbiota and promotes healthy digestion.
The Myth of the Perfect Ratio
Is there a "magic" macronutrient ratio for weight loss? The research is clear: no. When calorie intake is equal, low-fat, high-protein, high-fat, or even ketogenic diets all lead to equivalent weight loss. In other words, weight loss depends on energy balance, not on the ratio of macronutrients—and the ketogenic diet is no better than a high-carbohydrate diet.
That is why it all starts with energy balance, the key factor in weight.
Protein: The King of Muscle
While no single ratio is a “magic formula,” one macronutrient stands out for those who exercise: protein. The minimum recommended intake for the general population (0.8 g/kg per day) is insufficient for an active person. Organizations such as the American College of Sports Medicine recommend 1.4 to 2.0 g/kg per day instead, and consuming 20 to 30 g of protein after a workout promotes muscle growth and strength. Even during weight loss, a high protein intake helps preserve muscle mass—provided the calorie deficit remains reasonable. An important note: Our bodies can digest about 30 g of protein per meal.
Beyond the Ratio: The Right Models
Rather than focusing on percentages, it’s better to draw inspiration from proven dietary models. The Mediterranean diet—fruits and vegetables, whole grains, olive oil, nuts, legumes, and fish—is consistently associated with a reduced risk of cardiovascular disease, diabetes, cancer, and dementia.
Measure Your Allocation
Breathing analysis isn't just for measuring energy expenditure: by revealing the relative proportion of fat and carbs you burn at rest (your RER), it helps guide your macro distribution based on your goal. With PNOĒ, we replace guesswork with targets based on your actual metabolism.
References
Sacks FM, Bray GA, Carey VJ et al. “Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates.” N Engl J Med. 2009;360:859-873.
Carbone JW, Pasiakos SM. “Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefits.” Nutrients. 2019;11(5):1136.
Venn BJ. “Macronutrients and Human Health for the 21st Century.” Nutrients. 2020;12(8):2363.
Cena H, Calder PC. “Defining a Healthy Diet: Evidence for the Role of Contemporary Dietary Patterns in Health and Disease.” Nutrients. 2020;12(2):334.
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This article is provided for educational purposes only and does not constitute medical advice. If you have any health conditions, consult a doctor before starting to exercise.
