What Happens If I Don't Get Enough Protein?

As we’ve covered in previous articles, adequate protein is the cornerstone of a healthy body, weight loss, and muscle growth.

And, with high protein foods like meat, fish, eggs, yogurt, on top of supplements like protein bars and powder available everywhere, it seems hard to imagine that people would ever be deficient. Sadly, this does not seem to be the case.


To start however, we need to understand the difference between medical malnourishment of protein, and eating enough protein to optimize your long-term health.

Protein-Energy Malnutrition (PEM)

Due to the availability of protein, medically diagnosed PEM is quite rare. 

The term for severe protein deficiency is marasmic kwashiorkor. This is the most extreme form of malnutrition, usually coupled with general starvation. One of the adverse effects of kwashiorkor is edema or fluid buildup in the tissues. You may have seen pictures of children in developing countries currently in famine with large bellies -  this is a common symptom of kwashiorkor.

While this is ailment is uncommon in developed countries, that does not mean everyone is eating enough protein - long-term protein deficiency in our diets can show up in other pernicious ways.

Dietary Guidelines vs Optimal Health

The DRI (Dietary Reference Intake) in Canada and the US is 0.8 grams of protein per kilogram of body weight, or 0.36 grams per pound. This equals 56 grams per day for the average sedentary man. 46 grams per day for the average sedentary woman.

If you’re more active, or have a higher percentage of muscle (i.e. higher lean body mass), the requirements go up significantly


Grams (g) of protein per pound (lb) of lean body mass


No activity


Moderately Active

20+ mins of activity 2-3 times a week



30+ mins activity 3-5 times a week


Very Active

Vigorous activity 1 hour+, 5+ times a week 



2x times per day of vigorous activity


If you eat under this amount, you’re susceptible to a host of terrible symptoms, including:

  • Muscle loss
    • Protein is necessary for the maintenance, repair, and subsequent growth of muscle. Without adequate protein, any muscle broken down throughout the day won’t be re-built, resulting in a host of issues. This includes: soreness, weakness, and posture problems. Muscle mass isn’t just for bodybuilders - its a foundational piece that supports many downstream health benefits
  • Proneness to injury, and poor healing
    • Without being able to properly support our muscles and connective tissues with protein, we are much more prone to injury, and take longer to recover
    • This is also true for cuts and scrapes. Beyond muscle, protein is required to repair skin, provide oxygen in our blood required to heal and helps fight infections.
  • Weakened immune system
    • Proteins are made up of building blocks called Amino Acids. When we digest protein, we break it down into amino acids which are key for creating the antibodies that activate white blood cells to fight off viruses, bacteria, and toxins.
  • Swelling
    • The proteins help to hold salt and water inside the blood vessels so fluid does not leak out into the tissues. If a blood protein, called albumin, gets too low, fluid is retained and edema occurs, especially in the feet, ankles and lower legs
  • Mood stabilization
    • Neurotransmitters are our chemical messengers which transmit signals across our bodies. These messengers impact a bunch of physical and psychological functions including: heart rate, sleep, appetite, mood, and fear. Many of these neurotransmitters are made of amino acids - the building blocks of protein.  
  • Fatigue, weakness
    • Without adequate protein, you will not be able to recover and repair properly any wear and tear on your body from the day, causing fatigue and weakness. Further, many protein sources are high in iron. A deficiency of iron (anemia), will further weaken the body.
  • Hunger
    • Studies have found that eating foods high in protein helps you feel satiated (fuller) throughout the day. This is hugely beneficial in diet adherence, since you're likely to eat less calories if you’re not hungry.

Further, if you’re compensating less protein for higher carbohydrates in your diet, you run the risk of some of the most dangerous diseases in our society today:

  • Heart Disease
  • Obesity
  • High blood pressure
  • High blood cholesterol
  • Diabetes

Deficiency From incomplete, Low Quality Protein Sources

Even if you eat enough protein, if you’re not getting enough high quality protein, you might still be deficient. This is a especially a risk for those primarily on plant-based diets.

Protein quality (or “completeness”) is measured based on:

  • Ability to provide us with essential amino acids - those that our body cannot produce on its own
  • Digestibility - how much of the protein you eat actually ends up being absorbed into our bodies.

The highest quality, complete protein comes from animal based protein: meat, poultry, fish, eggs, and dairy.

The only complete sources of protein from plant-based sources are: quinoa, algae spirulina, and peas.

If you’re vegan or vegetarian, or generally eat mostly plants, it’s important to make sure you’re getting enough protein from these sources so a deficiency doesn’t occur.

More protein isn’t bad

If you’re intentionally reducing your protein because you’re worried about excess amounts, please reconsider.

Eating more protein than the minimum isn’t a bad thing. In fact it’s the best nutrient to eat more of after hitting your minimum requirements for fat and carbs. It’s very hard to eat in excess, and there are a ton of benefits.

Make sure you’re eating adequate amounts of protein every day. Consider eating Proteina as a complete, whole, and lean source of protein to hit your daily intake easily.