Fat vs. Protein on Keto

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Written by Rahul Malpe, Certified Nutritionist and medically reviewed by Abby Courtenay

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If you’re familiar with the ketogenic diet, you probably know that cutting out carbs and eating more fat is the key to ketosis. But what about protein? 

How do you balance fat and protein on keto, and what are the best sources of both?

In this post, we'll take a look at the science behind fats vs proteins on keto and how to use this knowledge for a healthy and effective ketogenic diet. 


About fat on keto

First of all, let's explore the different types of fats and their physiology before we discuss the importance of these fats on keto.

When it comes to fats, there are three main types: saturated, unsaturated, and trans fat. 


Saturated fats 

This type is most commonly found in highly processed foods like savory snacks or processed meats as well as animal products, such as meat, dairy, and eggs. It is also found in some plant-based foods, such as coconut and palm oil. 

Saturated fat is solid at room temperature.

Excessive consumption of this type of fat is known to raise LDL ("bad") cholesterol levels in the blood, which can increase risk for heart disease. For this reason, it is recommended to limit saturated fat intake to no more than 10% of total daily calories. 


Unsaturated fats 

This type is found mainly in plant-based foods, such as nuts and seeds. 

Unsaturated fat is liquid at room temperature. 

You should aim to replace saturated fats with unsaturated fats to reduce the risk of heart disease.


Trans fats

This is a type of unsaturated fat that occurs naturally in small amounts in some animal products, such as milk and meat. 

However, most trans fat is artificially created through a process known as hydrogenation, which involves adding hydrogen to vegetable oil. This process makes the oil more solid and less likely to spoil, which extends its shelf life. 

This kind of fat is often used in commercial baking and deep frying because it is cheaper and longer lasting than other types of fats. Unfortunately, trans fat has been linked to a number of health problems, including heart disease and stroke. When consumed in large quantities, trans fat can raise LDL (bad) cholesterol levels and lower HDL (good) cholesterol levels, increasing the risk of heart disease.


Importance of fat on keto

As you may know, the ketogenic diet is a high-fat, low-carbohydrate diet that alters the body’s metabolism so that it uses fat as its primary source of energy instead of carbohydrates.

When you eat foods high in carbs, your body produces glucose and insulin. Glucose is the simplest form of sugar and is the main source of energy for the body. Insulin is a hormone produced by the pancreas that helps the body store glucose in muscles and organs. 

When you eat fewer carbs, your blood sugar levels drop and there are no longer any spikes in insulin production. This forces your body to start burning stored fats for energy and makes it enter the state of ketosis.

While in ketosis, fat is broken down in the liver and turned into ketones, which can then be used for energy by the brain and other tissues. 

Since ketones are made from fat, it is a very important macronutrient in a keto diet. 

Ketones have been shown to reduce hunger and increase satiety. This explains part of why keto diets promote weight loss: by reducing appetite and promoting feelings of fullness. 

Depending on how you control your intake, ketones can be more stable than blood sugar, so they may provide a more consistent source of energy. This is part of why so many people report positive changes in how they feel after going keto. 


What happens when you don't eat enough fat on keto?

One of the most common mistakes people make when starting a ketogenic diet is not eating enough fat, which means they are not eating enough energy for daily processes. 

While it’s true that this low-carb, high-fat way of eating can lead to weight loss, it’s also important to make sure you’re getting enough fat to support your body and mind.

Without adequate intake of this macronutrient, you may experience some unpleasant side effects, such as fatigue, brain fog, and headaches. In addition, not getting enough of it can also stall your weight loss progress. This is because when you cut carbs, your body needs another source of energy, and fat is that fuel. 

Without enough fat in your diet, your body will start breaking down muscle for energy, which can lead to muscle loss and a slowdown in your metabolism. So if you’re feeling less than stellar on keto, make sure you’re getting enough healthy fats through your diet.


About protein on keto

Proteins are essential nutrients for the human body. They are the building blocks of muscle, bone, skin, and other tissues. These nutrients are also involved in the production of enzymes, hormones, and other important molecules. 

In order to function properly, the body needs a constant supply of proteins. The only way that the body can store this is as muscle, so to maintain your muscle mass you need to consume protein on a regular basis. 

The amount of protein required by the body depends on a number of factors, including age, activity level, and muscle mass. Athletes and people who have very active lifestyles generally require more protein on keto than sedentary people or those who have a more moderate level of activity. 

That’s why a keto macros calculator will ask about your age and how active you are, so it can adjust your protein levels accordingly.

These nutrients are made up of individual units called amino acids. There are 20 different amino acids that can be used to make proteins. 

Of these 20 amino acids, 9 are considered to be essential because the human body cannot produce them on its own. Essential amino acids must be obtained through diet or supplementation. Non-essential amino acids can be produced by the body, so they don't need to be consumed in foods or supplements. 

Most proteins contain all 20 amino acids in varying proportions. Animal-based proteins tend to contain all 9 essential amino acids in relatively equal amounts, while plant-based ones typically contain smaller amounts of some or all of the essential amino acids. 

By eating a varied diet, you can meet your protein and essential amino acid requirements. 

Vegans and vegetarians on keto can include plant-based protein sources like seitan, tofu, edamame, soy milk, nutritional yeast, chia seeds, hemp seeds, nuts and natural nut butters, and small amounts of lentils, chickpeas, beans, or quinoa.  Vegetables like artichokes, asparagus, broccoli, Brussels sprouts, and spinach also contain some protein.


What happens when you don't eat enough protein on keto?

Protein plays a role in everything from immune function to cell repair, and not getting enough of it can have serious consequences. 

One of the most visible signs of protein deficiency is muscle wasting. Without enough, the body can't build or maintain muscle tissue. 

This can lead to weakness and frailty, and make it difficult to recover from injuries. 

Protein is also essential for bone health. Without enough, bones can become weak and brittle, increasing the risk of fractures. 

In addition, protein is needed for the production of enzymes and hormones, so a lack of this can cause problems with digestion, metabolism, and hormone regulation. 

Ultimately, not getting enough protein can have a major impact on overall health and well-being.


Fat vs protein

On a keto diet, fat and protein both play an important role. A table is included below to compare these two.

Insights Fat Protein
Function in the body
  • Provides energy
  • Insulation
  • Assists with the absorption of vitamins
  • Aids in cell membrane development
  • Hormone production
  • Muscle and tissue building
  • Provides the substrate to repair damaged cells and tissues
  • Maintains fluid balance
  • Maintains healthy skin, hair, and nails
  • Supports immune health
  • Provides the substrate to produce hormones and enzymes
Recommended amount on keto As part of a keto diet, you should consume approx 70-80% of your daily calories from fat. This amounts to 156 - 178 g of fat on a 2,000-calorie diet. The recommended amount of protein on a keto diet is 20-25% of your overall calories. This translates to about 75 g on a 2,000-calorie diet.
Healthy sources to include
  • Avocadoes
  • Nuts
  • Seeds
    • Chia seeds
    • Flax seeds
    • Hemp seeds
  • Oils
    • Olive oil
    • Coconut oil
  • Fatty fish
  • Unsweetened dairy products
Grass-fed beef
Greek yogurt
Low-carb protein powders (like whey protein isolate)
Unhealthy sources to avoid
  • Refined oils
  • Fried foods
  • Margarine
  • Vegetable shortening
  • Processed meat (hot dogs, sausages, bacon, deli meats)
  • Processed meats, deli meats and sausages
  • Candied nuts
  • Processed protein bars
  • Mass gainer powders (may contain carbs)
  • Sweetened dairy products



So, which is better for keto — fat or protein? The answer is both! Fats and protein are both essential in a keto diet.

They each have a necessary role to play in the body. Make sure you include both based on the recommended ratios so that you can reach your keto goals.



Would you like to know more about these macronutrients? Below we answer some more questions.

It's typically recommended that fats should make up around 70-80% of your daily intake, protein should only account for 20-25% on keto. 

However, your protein intake may vary depending on several factors, including whether you are training at high intensity or recovering from an injury or illness. In these situations, an increase in protein intake is recommended.

Both are important. You must have a sufficient supply of both for the body to carry out its necessary functions. 

While on a keto diet, the goal is to achieve and remain in the state of ketosis for which your diet should consist of a majority of fats. However, this does not negate the significance of protein, which plays a crucial role in the human body.

Eating excess protein on a keto diet can kick you out of ketosis. This happens because your body will convert the excess protein into glucose, which can be used for energy. As a result, you'll find it difficult to reach and maintain the state of ketosis. 

Overall, it's best to stick to the recommended ratios of fat to protein when following a keto diet. However, if you do eat more protein than fats, don't worry — it's not the end of the world. All you need to do is make certain that your diet is modified according to the recommended ratios and you will be back on track in no time.

To lose weight on keto or any diet, you must eat fewer calories than you burn. This can be done with a combination of diet (eating less calories) and exercise (burning more calories).

Being in ketosis can have additional benefits for weight loss, like reducing hunger (leading you to eat less calories). To get into ketosis, the keto ratios are around 70-80% fat, 20% protein, and 5-10% carbs, though the exact numbers are different for each person.