To get the most benefit from a ketogenic diet, you need to eat carefully. A mistake could decrease your level of ketosis and delay your progress healing or losing weight. Understanding the basics of macronutrient breakdown and use can help you avoid that pitfall.Each macronutrient is dealt with in a different way, and your bodily state (fed, fasted or starved) impacts their use. The type of food, how often and how much of it you eat will affect whether or not you are in ketosis.


There are three macronutrients (main nutrients) in all foods: protein, fat and carbohydrate. On a ketogenic diet, your daily macros will be about 70 to 75 percent fat, 20 to 25 percent protein and 5 percent carb. The point of this is to keep glucose levels low enough to use fat for energy.The source of glucose is carbohydrates, but our body is also capable of making glucose out of available nutrients. There are a few tissues that can only use glucose for energy production, such as a portion of the brain. That makes gluconeogenesis (the creation of new glucose) a vital process. Without it, these tissues could starve in the absence of carbohydrates.However, glucose has a negative effect on ketosis. A very small amount will not really impact it, but a small amount could slow it down. A large amount will downright stop ketosis.Each macronutrient is at least a little bit “anti-ketogenic,” or not conducive to ketosis. Whether or not that effects ketosis depends on how much of them you eat.


Fat should be your primary source of calories on keto (70 to 75 percent). It is twice as calorie dense as both protein and carbs. Fat is only about 10 percent anti-ketogenic, which results from the small amount of glucose that is released during triglyceride conversion.This is not really a concern though, since the amount is quite low. Each gram of fat equals 0.1 grams of glucose. If your daily fat macro is 150 grams, that would only be 15 grams of glucose. Keep in mind that that glucose release would be spread out throughout the day. It wouldn’t even cause a hiccup in ketosis.


Protein makes up about a quarter of your daily calories, but it helps you feel full. It is the most sating (hunger-satisfying) macronutrient. It is roughly half anti-ketogenic. This is due to the release of glucagon, which is a hormone that is released when blood-sugar levels are low. Dietary protein causes a rise in glucagon which triggers a rise in insulin. When that happens, ketone production slows.Because of that, we want to avoid eating very large quantities of meat often. Yes, it tastes great, but constantly stuffing yourself on meat will keep your ketone levels low. That doesn’t mean never though. If I was out and presented with not-so-great options, I’d take plenty of meat over high-starch, high-sugar foods.The appropriate amount of protein varies by individual. The standard range is roughly 0.7 to 1.2 grams per pound of lean mass (not total weight). The more active you are, the more likely it is that you can lean toward the higher end of the spectrum. However, this is not a hard and fast rule; some more-sedentary people can consume more protein and still maintain optimal ketosis. Testing your ketone levels can help you nail it down.


Carbs are nothing but sugar. Yes, even the starch is just sugar that gets knocked apart during digestion. They are 100 percent anti-ketogenic because they are glucose. That is why carb consumption needs to be limited to less than 20 to 30 grams per day on keto.Every gram of carbohydrate will be converted to nearly a gram of glucose, so it adds up quickly! Just like the glucose from fat, a little bit of glucose spread out throughout the day isn’t problematic. However, it also doesn’t take much (in terms of the standard American diet) to stop ketosis completely.


There are three ways that your body can respond or use nutrients based on when and how much you eat. You can be fed, fasted or starved. To clarify, “starved” doesn’t mean that you are literally starving to death. A starved state can result from long fasts or ketosis; it is being starved of glucose. Here’s how nutrients are used in those three states.


The fed state lasts for some time after we eat. It is different for every person. The biggest factors are how much carb you ate and how insulin resistant you are. More carbs and more resistance means a longer time for glucose to clear from the system. Since glucose is used first, we’ll start there. 

Carbohydrates are broken down into glucose and absorbed into the bloodstream. The liver takes its share off the top and the muscles will take what they can hold; both store it as glycogen. An insulin release is triggered by glucose in the blood, which shuttles the glucose into storage. Any glucose not stored in the liver and muscles is converted to fat for storage. 

Protein is broken down into its component amino acids and sent into the body. Amino acids (AA) are building blocks and are a large portion of our cellular structure. They are crucial in almost every biological process and are deposited in AA pools for use. Any extra AA are broken down into metabolites and can be used to create glucose or keto acids. The metabolite type determines the process they enter. 

Fat goes straight to the liver and are broken into fatty acids and glycerol. Fatty acids are used to make tissues, hormones and other chemicals and also to repair cells. Fats that are in excess of our needs are stored in fat cells.



When we are in a fasted state, we will use fat and glycogen for energy. 

• The liver delivers glucose to the bloodstream, which is used for tissues that must run on it. That is mostly the brain and red blood cells. 

• Triglycerides are released from fat cells. When we sleep, the free fatty acids provide the majority of the energy for the liver and muscles. More triglycerides are released as needed while the fasted state extends. Some of them will be converted to ketones by the liver. 

Both the glucose and the fatty acids are metabolized in the same way. They are broken down into an important component of ATP creation called acetyl-CoA. ATP is an energy molecule that is created through the Kreb’s cycle. The ketones that the liver creates can also be used if needed.


Once our glycogen stores in the liver and muscles run out, we transition into the starved state. When you consume a standard diet, this usually happens around 48 hours fasted. We go through a short period of using gluconeogenesis to provide for our energy needs while we transition to ketone production.Gluconeogenesis (GNG) actually stays at a very steady low rate. Some tissues (notably, the liver, red blood cells and a small part of the brain and kidneys) need to have glucose-based energy. GNG will keep running quietly in the background and “drip” glucose into the blood for those tissues. 

While the liver is producing some glucose, it will also create ketone bodies (aka ketones) from fats. They are released into the bloodstream and picked up for use by muscles and the brain.




The above processes are a touch complicated, but the takeaway is pretty simple. When you eat a ketogenic diet, you mimic starvation. The body is starved for glucose and continually activates fat stores for energy. 

This is in direct contrast to the standard American diet, which would keep us in the fed and fasted states. The high glucose levels and the presence of insulin prevent us from tapping into our fat stores. Conversely, keto keeps both glucose and insulin low and makes for amazing fat-burning capabilities! 

When you understand that, keto becomes the obvious choice for your health and wellbeing. You can read about the health benefits here.

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