Not getting enough protein can put you at risk for a wide range of health impacts over time. Some risks only occur when your case is severe, but others can show up even when your protein deficiency is relatively small.
Bone Fractures
Protein is integral to bone health, including preserving bone density and preventing osteoporosis (8). That’s one of the reasons we recommend daily collagen to people who are worried about their bone density. If you’re not getting enough protein, your bones can become fragile, your muscles can get weaker, and your balance can get flimsier. This means a higher risk of fractures and falls (9, 10, 11, 12, 13).
Loss of Muscle Mass
Your muscles rely on protein to function. When you’re not getting enough, your muscles may start to waste. This can happen even if your hypoproteinemia isn’t a severe case, especially if you’re older (14). In fact, increased protein intake could actually help slow down the natural muscle degeneration process that comes with age (15).
Increased Appetite
Severe protein deficiency usually zaps a person’s appetite. But if you have more mild hypoproteinemia, odds are high that your body is ramping up your appetite to encourage you to eat more protein (16). This can cause cravings for savory foods in particular (17). Unfortunately, this can mean reaching for foods that are low in nutrients (and still low in protein!) that simply add to your daily calorie count and cause weight gain without making you any healthier (18).
Weaker Immune System
Low protein intake can make your immune system weaker (19). This can make you more prone to infections, including exhausting illnesses like the cold or flu (20, 21).
Changes in Hair, Skin, and Nails
Hypoproteinemia, especially in its more severe forms, can cause thinning hair, faded hair color, and alopecia (hair loss) (22, 23). You may also experience weak, brittle nails and dry, red, or flaky skin (24, 25).
Fatty Liver
The most severe form of protein deficiency is a type of malnutrition called kwashiorkor. If you are reading this article, you probably won’t see kwashiorkor in your everyday life—it’s usually seen in places where people are experiencing famine and food shortages. That said, a common result of kwashiorkor is fatty liver, which can develop into fatty liver disease if left untreated (26, 27).
Edema
Edema is another common symptom of kwashiorkor. Experts believe this probably happens because the body is experiencing low levels of albumin, the type of protein that’s ordinarily produced by the liver (28). Edema caused by protein deficiency can include swollen skin and bloating or fluid build-up in the stomach.