Protein is important for the functioning of your entire body, from your bones, muscles and connective tissues to your hair, skin, nails to lining of your GI tract and blood vessels.
Protein gets broken down into molecules called amino acids, some your body needs but can’t produce on its own.
Protein and the amino acids it breaks down into are responsible for:
- Building muscle
- Maintaining the structure of your muscles, tissues, and organs
- Making enzymes
- Creating hormones
- Building neurotransmitters
- Metabolizing your food and transporting nutrients
- Producing antibodies to strengthen your immune system
- Transporting oxygen in your blood via hemoglobin
- Helps you feel full. Protein is super nutrient dense, satiating, and is slow to digest. This helps with curbing hunger.
- Builds muscle, which burns calories even when you’re not working out. It will be easier for you to lose stubborn fat with more muscle mass.
- Is essential for recovery after your workouts because every time you tear your muscles at the gym, you need protein to build them back up bigger and stronger.
Your body is unable store protein in the same way it stores carbs and fat, making eating the right amount of protein for you necessary for your health and wellness.
Protein & Keto
Many following a ketogenic diet (wrongfully) believe that too much protein will put them out of ketosis through a process called gluconeogenesis. This translates to people limiting their protein intake to the point they are not eating sufficient protein to maintain muscle mass and regulate other important functions in your body.
Not eating enough protein on keto can have serious side effects, including:
- Decreased performance and stamina: Without enough protein, you won’t be able to maintain muscle mass, let alone build muscle. As you lose muscle mass, you’ll feel weaker and less capable of exercising at the same level as before.
- Neuron atrophy: Your brain needs amino acids to function optimally and a protein deficient diet can lead to brain cells gradually declining in effectiveness.
- Weaker immune system: A deficiency in the amino acid arginine can contribute to the dysfunction the cells that regulate your immunity.
- Increased risk of diseases: A deficiency in amino acids can increase the risk of developing certain diseases, including acute asthma, cystic fibrosis, high blood pressure and cardiovascular disease
What Is Gluconeogenesis
The same way too much glucose is toxic, too little can kill you. The body keeps glucose levels tightly regulated.
When you eat carb-based meals, your body can easily make new glucose from those carbohydrates. When following a ketogenic diet, these carbohydrates are removed and cells need to find an alternative method for creating glucose for those tissues that cannot run on ketones.
Gluconeogenesis is the body’s alternative glucose source and occurs when your body forms glucose from protein when lacking in sufficient carbohydrate.
In healthy people, 24-hour blood sugar levels average between 5.5–6 mmol/L, going up to about 9 mmol/L after carb-based meals and a minimum of 3 mmol/L in a prolonged state of fast.
Gluconeogenesis prevents glucose levels from falling under that limit when you’re not eating carbohydrates. Without it, your blood sugar could run dangerously low risking seizures, confusion, loss of consciousness, and death.
Red blood cells, kidney medulla (inner part of the kidney), testicles and the retina are unable to metabolize ketones. Gluconeogenesis provides them with enough glucose to remain healthy when in ketosis.
The brain also needs a little bit of glucose to work optimally, but not only glucose. Ketones can cover up to 70% of your brain’s energy while glucose from gluconeogenesis can cover the rest.
You may have read somewhere on the internet that eating too much protein on keto can trigger gluconeogenesis and put you right back on glucose-burning mode, but the truth is this isn’t something you should worry about.
Gluconeogenesis Is an Essential Mechanism
Making glucose from non-carb sources is crucial for survival when you’re becoming fat-adapted, in ketosis or fasting. It helps nourish glucose-needing tissues, build your muscle glycogen, and prevent hypoglycemia.
It is unnecessary obsess over protein macros on keto — eating a lot of protein is not enough to increase the highly stable rate of gluconeogenesis, and your body also prefers lactate before amino acids for this process.
Next time, don’t hesitate to go heavy on the meat if you feel like it — you’ll most likely stay in ketosis without a problem.
How Much Protein
Finding the ideal protein intake on keto depends on many factors:
Genetic expression can impact the degree of insulin resistance and sensitivity throughout the body as well as the ability to burn ketones for fuel. Both will affect hormonal response to protein consumption.
Women may have a different response to protein depending on what phase of their cycle they are in.
Calories and Macronutrient Ratios.
In general, eating fewer carbs and/or calories can keep higher protein intake from reducing your ketone levels.
Restricting carbs will help decrease insulin levels and increase your ability to produce and burn ketones. The longer you are on the keto diet, the less likely a higher protein intake will disrupt ketosis.
The heavier you are, the more protein you will need to eat. If you have a higher body fat %, higher protein intakes may cause enough of an increase in insulin levels to decrease ketone production.
Ideally, you want to eat enough protein so that you maintain/gain muscle mass without it decreasing ketone levels.
People who have type 2 diabetes may struggle with ketone production because of their higher insulin levels, and protein consumption can cause their insulin to get even higher. On the other hand, healthier and more fit individuals can get away with consuming more protein without it impairing ketone production
Activity, especially weight lifting, will require more protein to restore glycogen levels and build muscle. Less insulin is required to make use of that protein. This means that ketone production will continue to be stimulated, even after high protein meals.
Each one of these variables will affect how much insulin and glucagon are secreted in response to protein consumption. This will then determine how much that protein affects ketone production and other processes in the body (e.g., muscle protein synthesis).
Most keto dieters have no problem at all when they follow these general protein recommendations:
Sedentary — consume 0.6 – 0.8g of protein per pound of lean body mass.
Regularly Active — have 0.8 – 1.0g of protein per pound of lean body mass.
Lift Weights — eat 1.0 – 1.2g of protein per pound of lean body mass.
Favorite Protein Sources
Beef. Ground beef, steak, roasts, and stew meat. Stick with fattier cuts and 100% grass-fed when possible.
Other Meat. Veal, goat, lamb, and other wild game. Stick with fattier cuts when possible.
Fish. Preferably eating anything that is caught wild like catfish, cod, flounder, halibut, mackerel, mahi-mahi, salmon, snapper, trout, and tuna. Fattier fish is better.
Shellfish. Clams, oysters, lobster, crab, scallops, mussels, and squid.
Whole Eggs. Try to get them pasture-raised from the local market if possible. You can prepare them in any way you’d like.
Pork. Ground pork, pork loin, pork chops, tenderloin, and ham. Watch out for added sugars and try to stick with fattier cuts.
Poultry. Chicken, duck, quail, turkey, pheasant and other wild poultry.
Offal/Organ. Heart, liver, kidney, and tongue. Offal is one of the best sources of vitamins, antioxidants, and minerals.
Bacon and Sausage. Check labels for anything cured in sugar, or if it contains extra fillers. Don’t be overly concerned with nitrates.
Cheese. Cheddar, mozzarella, parmesan, and other hard cheeses. Always purchase full-fat cheeses.
Nut Butter. Go for natural, unsweetened nuts and try to stick with fattier versions like almond butter and macadamia nut butter. Legumes (peanuts) and almonds are high in omega 6’s so be careful about over-consumption.
Keto-Friendly Protein. 100% grass-fed whey protein, collagen protein, casein protein, pea protein isolate, and any other very low-carb protein powders.
Although it is true that eating too much protein can decrease your ketone levels, you may never come close to reaching that point. In general, as long as you stay within these ranges (and keep your carbs below 25 grams) you should have no problem entering and staying in ketosis within the context of a well formulated ketogenic diet.