What are the red flags that you need to eat more protein?

October 20, 2025 •

5 min read

According to a 2024 article from the Cleveland Clinic, low protein in your blood, also known as hypoproteinemia, can be linked to a variety of symptoms, including dry skin, fatigue, and frequent infections. Many people underestimate their daily protein needs, leading to subtle but persistent issues that can signal a deficiency. Recognizing what are the red flags that you need to eat more protein is the first step toward improving your overall health and well-being.

Quick Summary

This article explores the subtle and not-so-subtle signs your body gives when it needs more protein. It covers indicators related to energy levels, physical appearance, mood, and immune health, and provides actionable advice for increasing protein intake through a balanced diet.

Key Points

Muscle Atrophy: Unexplained loss of muscle mass, even with regular exercise, can signal the body is breaking down its protein reserves.
Hair, Skin, and Nail Deterioration: Signs like brittle hair, flaky skin, and weak nails often appear when protein is scarce, as the body redirects this nutrient to more critical functions.
Persistent Fatigue and Brain Fog: Protein is crucial for steady energy and neurotransmitter production; its deficiency can lead to constant tiredness and difficulty concentrating.
Swelling (Edema): Swelling in the ankles, feet, or abdomen can be a sign of severe protein deficiency, caused by a fluid imbalance in the blood.
Increased Hunger and Cravings: Inadequate protein can cause blood sugar fluctuations, leading to constant hunger and intense cravings for carbs and sugar.
Compromised Immune System: A weak immune response, resulting in frequent or prolonged illnesses, can be a direct result of low protein intake.

Your Body's Silent SOS: Recognizing the Signs of Low Protein

Protein is a crucial macronutrient, a fundamental building block for every cell in your body. Its responsibilities are vast and include repairing tissues, building muscles, creating hormones and enzymes, and bolstering your immune system. When your diet doesn't provide enough, your body begins to show subtle signs, pulling protein from less vital functions to preserve essential ones. This article details the key red flags that you need to eat more protein and how to address them through your diet.

Physical and Muscular Signs of a Protein Gap

One of the most noticeable areas where a protein deficiency manifests is in your physical form. Your body's largest protein store is in your muscles, so it's a primary target when your dietary intake is low.

Loss of Muscle Mass and Strength: If you're exercising regularly but seeing little to no muscle growth, or if you notice your muscles feel weaker than before, it could be a sign of inadequate protein. The body will break down muscle tissue to acquire the amino acids it needs for more critical functions, a process known as muscle atrophy. This is particularly relevant for older adults, who are already at risk for age-related muscle loss (sarcopenia).
Slow Wound Healing: Protein is essential for tissue repair and growth, including the formation of collagen, a key component of skin and connective tissues. If cuts, scrapes, or other injuries seem to take an unusually long time to heal, it may indicate a protein deficit that is hindering your body's regenerative abilities.
Hair, Skin, and Nail Problems: These tissues are largely composed of proteins like keratin, collagen, and elastin. When protein intake is insufficient, it's common to see changes such as:
- Thinning or brittle hair, and in severe cases, hair loss.
- Dry, flaky skin or rashes.
- Brittle, ridged, or peeling nails.

Hormonal and Immune System Imbalances

Proteins are not just structural; they are also functional, creating hormones and enzymes that regulate countless bodily processes.

Weakened Immune System: Antibodies, the specialized proteins that fight off viruses and bacteria, are synthesized from amino acids. A lack of dietary protein can suppress the immune system, leading to more frequent infections, and a longer recovery time from illness.
Edema (Swelling): This is a classic, though typically severe, symptom of protein deficiency. Proteins in the blood, particularly albumin, help maintain the balance of fluids in your body. When protein levels drop, fluid can leak from blood vessels into surrounding tissues, causing swelling, especially in the hands, feet, and ankles.

Appetite and Energy Fluctuations

Your relationship with food and your energy levels are closely tied to your protein intake. Protein has a high satiety effect, meaning it helps you feel full and satisfied.

Constant Hunger and Cravings: If you feel hungry shortly after eating, especially a meal high in carbohydrates, it could be a sign you're lacking protein. Protein slows digestion, helping to stabilize blood sugar levels and curb the hunger hormone ghrelin.
Sugar Cravings: Low protein intake can cause blood sugar levels to fluctuate erratically. When your blood sugar crashes after a carb-heavy meal, your body will crave quick energy, often in the form of sugary snacks, creating a vicious cycle.
Relentless Fatigue and Brain Fog: Protein is vital for providing energy and producing neurotransmitters that keep you alert and focused. A deficiency can lead to feelings of sluggishness, brain fog, and difficulty concentrating.

Comparison of Animal vs. Plant-Based Protein Sources

Understanding the differences between animal and plant-based proteins can help you make informed dietary choices to address a deficiency. Animal proteins are considered 'complete' as they contain all nine essential amino acids, while most plant proteins are 'incomplete'. However, by combining various plant sources, you can easily achieve a complete amino acid profile.


Feature	Animal Protein Sources	Plant-Based Protein Sources
Essential Amino Acids	Complete (contain all nine essential amino acids)	Most are incomplete; combining different sources (e.g., rice and beans) makes a complete protein.
Nutrient Profile	Rich in iron, zinc, and B vitamins.	Often rich in fiber, vitamins, minerals, antioxidants, and healthy fats.
Digestibility	Highly digestible and bioavailable.	Varies; some are less bioavailable than animal proteins.
Examples	Lean meats, poultry, fish, eggs, dairy.	Legumes (beans, lentils), nuts, seeds, soy products (tofu, tempeh), quinoa.
Saturated Fat	Some sources are high in saturated fat (e.g., fatty beef, full-fat dairy).	Naturally low in saturated fat and cholesterol-free.

What to Do If You See These Red Flags

Prioritize Protein at Every Meal: Instead of a bagel for breakfast, try eggs with some chicken sausage. At lunch, top your salad with grilled chicken or chickpeas. For dinner, add fish, lentils, or lean beef to your plate.
Choose High-Quality Sources: Opt for lean meats, poultry, fish, eggs, dairy, and a wide variety of legumes, nuts, and seeds to ensure a broad spectrum of amino acids.
Use Strategic Snacking: Incorporate protein-rich snacks throughout the day, such as Greek yogurt, a handful of almonds, or a protein shake. This helps maintain steady energy and amino acid levels.
Consider Plant-Based Combinations: If you follow a plant-based diet, remember to combine different protein sources. For instance, pairing rice and beans or hummus and whole-grain pita ensures you get a complete set of essential amino acids.
Consult a Professional: If symptoms are severe or persistent, it is important to consult a healthcare provider or registered dietitian. They can help rule out other conditions and develop a personalized nutrition plan.

Conclusion

Ignoring the subtle signs of low protein can have a cascading effect on your health, from impacting your energy and mood to weakening your immune system and compromising your physical appearance. By recognizing these red flags and making conscious dietary adjustments to prioritize high-quality protein, you can begin to repair the damage and support your body's optimal function. Listen to your body—it's likely asking for more protein than you think. A well-balanced diet rich in diverse protein sources is your best defense against the side effects of deficiency, paving the way for stronger muscles, clearer skin, and greater overall vitality.

Frequently Asked Questions

The Recommended Dietary Allowance (RDA) is 0.8 grams of protein per kilogram of body weight for minimally active adults. However, this can vary significantly based on age, activity level, and health status, with athletes or older adults often requiring more.

Yes, it is possible to get all the necessary protein from a plant-based diet by consuming a variety of legumes, grains, nuts, and seeds throughout the day to ensure you get all the essential amino acids.

You can boost your protein intake with options like Greek yogurt, eggs, cottage cheese, beans, lentils, nuts, seeds, and soy products like tofu and tempeh. Protein powder supplements can also be a convenient addition.

For optimal muscle health, distribute your protein intake throughout the day rather than eating it all at once. Consuming protein within an hour or two after a workout can be especially beneficial for muscle repair and growth.

In many cases, hair thinning or loss due to protein deficiency can be reversed by correcting your dietary intake. However, persistent or severe hair loss should be evaluated by a healthcare provider.

Yes, protein provides the amino acids needed to create neurotransmitters like serotonin and dopamine. Low intake can affect mood, leading to increased irritability, anxiety, and brain fog.

While some symptoms like hunger and energy levels may improve relatively quickly, more significant changes, such as improved hair, skin, and nails or muscle mass, can take several weeks or even months to become noticeable.