Feeling weak? Uncover the sneaky signs of protein deficiency you can’t afford to ignore

A lack of protein can leave you feeling depleted as your body starts to break down muscle tissue for energy.

A lack of protein can leave you feeling depleted as your body starts to break down muscle tissue for energy.

Image by: Alesia Kozik/pexels

Published Apr 11, 2025

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Everywhere you turn, there’s advice about food: cut carbs, eat more greens, steer clear of sugar, or try the latest diet trend. But when it comes to protein, the conversation is often misleading. 

The reality may be more alarming than many of us realise. We live in a world that glorifies fad diets and quick-fix solutions, protein stands out as a nutritional superstar, yet many of us still fall short in their consumption. 

According to Dr Michael Garcia, a clinical nutritionist at UCLA Health, “Most adults aren’t quite getting enough protein, and what makes it tricky is that the exact amount you need depends on your lifestyle, activity level, and metabolism.”

Why should you care if you are getting enough protein? Protein is not merely a buzzword; it is the foundational element your body craves.

More than just a focus of gym discussions, protein is vital for maintaining muscle, skin, hair, and nails and plays an integral role in producing enzymes, hormones, and antibodies - basically, everything that keeps your body functioning like a well-oiled machine.  

Unlike carbs or fat, our bodies cannot store protein. That means you need to consume enough regularly to keep things running smoothly.  

What exactly is protein?  At the molecular level, proteins are made up of amino acids, which are considered the building blocks of life.

Despite having 20 amino acids to choose from, the human body can only manufacture 11 of them on its own. The other nine, called essential amino acids, must come from our diets.  

When we fail to eat protein-rich foods, our bodies eventually run out of these nutrients. And when that happens, it sometimes shows in ways you wouldn’t expect.  

Signs you might be protein deficient  

1. Weakness and fatigue 

Lack of protein can leave you feeling depleted as your body starts to break down muscle tissue for energy. This manifests as persistent tiredness and weakness. 

2. Hair loss and brittle nails

Our hair and nails are made mostly of keratin, a type of protein. Without enough protein in your diet, these structures begin to suffer. Hair may thin out, fall out, or lose its shine, while nails become brittle and prone to breaking.

3. Frequent illness and slow healing

Protein is essential for antibody production. A deficiency may contribute to a sluggish immune system, making you more susceptible to infections and slowing healing processes.

4. Mood Changes and brain fog

Protein plays a huge role in producing neurotransmitter chemicals in the brain that regulate mood and mental clarity. A lack of protein can lead to imbalances, contributing to mood swings, anxiety, or difficulty concentrating.

Our skin works hard to repair itself daily, and protein is a key player in this process. If you’re not getting enough, you might notice dry, flaky, or peeling skin.

5. Skin issues

Our skin works hard to repair itself daily, and protein is a key player in this process. If you’re not getting enough, you might notice dry, flaky, or peeling skin. Some people with protein deficiencies also experience increased sensitivity to rashes or irritation.  

6. Slow growth in children

For kids, protein is critical for growth and development. If a child isn’t getting enough protein, it can stunt their growth, delay developmental milestones, and even impact their immune system. If you’re noticing slow physical growth in a child, their protein intake should be one of the first things to examine.  

Why are protein deficiencies so common?  Despite the protein hype in the fitness and diet world, many people still fall short. This is especially true for those following restrictive diets like veganism, vegetarianism, or extreme calorie-cutting plans. 

While plant-based diets can be incredibly nutritious, they often require careful planning to ensure you’re getting all nine essential amino acids.  

Other factors, like malabsorption issues (for example, in people with celiac disease or Crohn’s disease), can also make it harder for the body to absorb nutrients from food.  

How much protein do you need?  The amount of protein you need varies depending on your age, activity level, and overall health.

A general guideline is:  

Sedentary (inactive) adults: 0.8 grams of protein per kilogram of body weight  Active individuals: 1.2–2.0 grams per kilogram  

Older adults: Slightly more protein than younger adults to maintain muscle mass.

Sources of everyday protein that are animal-based include chicken, turkey, eggs, fish, Greek yogurt, cheese, and lean beef. Plant-based: Lentils, chickpeas, quinoa, tofu, edamame, nuts, seeds