“Macros” is an abbreviation of the term macronutrients. Macronutrients are simply substances required in relatively large amounts by living organisms.
Carbohydrates, fat, and protein are the macronutrients that provide us with energy (calories). Carbs and protein each provide us with 4 calories of energy per gram, while fat consists of 9 calories per gram. Although they can all be converted into energy, each macro is used in the body in different ways.
From a ketosis and keto diet perspective, for example, they all have a different impact on our ability to produce ketones.
- Fats are 90% ketogenic and 10% anti-ketogenic, due to the small amount of glucose that is released in the conversion of triglycerides.
- Proteins typically tend to be around 46% ketogenic and 54% anti-ketogenic since insulin levels rise after eating specific amino acids.
- Carbohydrates are, of course, 100% anti-ketogenic because they raise both blood glucose and insulin, shutting down ketone production.
This is basically all you need to know to understand why you must eat a high fat, moderate protein, and very low carb to follow the keto diet correctly, but one question still remains:
Why not eat almost 100% fat if both protein and carbs are much more anti-ketogenic?
Because we also must consider the other purposes that each macro serves. Protein, for example, is essential for various processes throughout the body, including maintaining and building muscle mass.
In other words, if you don’t eat enough protein, then you are going to lose muscle and feel a lot less healthy. This is why it is important to eat the appropriate amount of protein based on your goals and activity levels.
Here is what we recommend for protein intake:
- Sedentary: 0.8g of protein per pound of lean body mass.
- Lightly Active: 0.8 – 1.0g of protein per pound of lean body mass.
- Highly Active: 1.0 – 1.2g of protein per pound of lean body mass.
Carbs, however, are not essential for health like protein and fat. With the help of a metabolic process in the liver called gluconeogenesis, we can meet all of our sugar requirements by making glucose from glycerol (found in fat) and gluconeogenic amino acids (found in protein). This is why many people are able to eat fewer than 30 grams of carbs while feeling better than they’ve ever felt before.
In general, here is what we recommend for most people from a macronutrient perspective:
- Restrict your net carb intake to between 20-30 grams (the net carb content of any food can be found by subtracting grams of fiber from the grams of total carbs.)
- Eat the right amount of protein for your activity level and body composition goals
- Use fat as a lever to help you maintain weight (by eating maintenance calories), gain weight (by being in a calorie surplus), or lose weight (by being in a calorie deficit).