Protein Deficiency Is a Health Risk. Here Are the Key Symptoms to Watch For

We may be living in the most food-abundant era in human history. Never before has there been such a wide variety of accessible foods—especially protein-rich options like meat and fish.

Despite this abundance, protein deficiencies still happen. They’re more common in people with restrictive diets, certain autoimmune disorders, or specific health conditions. So, how can you know if you’re not getting enough protein?

Proteins are one of the three essential macronutrients your body needs to function properly—the other two are fats and carbohydrates. They’re found in meat, fish, eggs, and dairy, but also in legumes, soy, and some grains.

Proteins are made of amino acids, the building blocks that keep your body running. Of the 20 amino acids the human body uses to form protein, 11 are made naturally. The other nine—called essential amino acids—must come from food.

Foods that contain all nine are known as complete proteins, and include beef, chicken, fish, eggs, dairy, soy, and quinoa.

More from Xataka On

Chinese Researchers Discover a Way to Recycle 99.9% of Electric Car Batteries: The Glycine in Your Protein Shakes

When your diet lacks enough protein—or the right kinds of protein—your body can’t produce the compounds it needs. This can lead to hypoproteinemia, a condition marked by low protein levels in the blood, and other health issues.

Symptoms of a Protein Deficiency

Experts at UCLA have identified six common signs that might indicate a protein deficiency:

1. Brittle hair and nails: These are often the first visible symptoms, as your body prioritizes essential systems over hair and nail growth.
2. Weakness and constant hunger: While hunger usually means you need more food, it can also point to missing nutrients—especially protein.
3. A weakened immune system: Protein helps your body build antibodies and repair tissues. Without it, you may get sick more often.
4. Mood swings and brain fog: Low protein intake can affect blood sugar levels and neurotransmitters, which can lead to irritability or difficulty concentrating.
5. Muscle loss or weakness: Protein is critical for maintaining and repairing muscle mass.
6. Stress fractures or weak bones: Bones rely on proteins like collagen for strength and flexibility.

Like most nutrients, too little or too much protein can be harmful. Some studies suggest that consuming more than 2 grams of protein per 2.2 pounds of body weight per day may have negative effects, particularly on kidney function over time.

A varied, well-rounded diet usually provides enough protein for the average person. If you cut out major food groups—by choice or due to health restrictions—it’s essential to ensure you’re still getting the nutrients your body needs. Remember: no single food is irreplaceable, but some nutrients are.

Image | Malidate Van

Related | Engineers Wanted to Simulate 500 Million Years of Evolution Using AI. They Found a New Fluorescent Protein Along the Way