Protein Guide
10 warning signs you're not eating enough protein
Severe protein deficiency (kwashiorkor) is rare in well-fed populations — but eating below your personal needs is common, and it shows up in ways people rarely connect back to diet.
- Constant fatigue — protein is needed to make the enzymes and transport proteins involved in energy metabolism
- Slow-healing cuts and bruises — tissue repair depends directly on amino acid availability
- Thinning hair or hair loss — hair is largely made of a protein called keratin
- Brittle, ridged, or slow-growing nails — same underlying cause as hair changes
- Getting sick often — antibodies are proteins; low intake can blunt immune response
- Unexplained swelling (edema), especially in the belly or legs — a hallmark of severe deficiency, caused by low blood protein levels affecting fluid balance[1]
- Losing muscle despite training — without enough amino acids, your body can't fully repair and build muscle tissue
- Constant hunger, especially cravings — protein is the most satiating macronutrient; low intake often shows up as never feeling full
- Mood changes or brain fog — several neurotransmitters are synthesized from amino acids
- Skin changes — dryness, rashes, or slow-fading marks
Most of these signs have other possible causes too, so they're not a diagnosis on their own — but if several apply and your diet is genuinely low in protein sources, it's worth checking your actual intake against your target.
Keep reading: What protein actually does · High-protein foods list · How much protein you need