Saturday, November 27, 2021

    7 Risks and Symptoms of Protein Deficiency


    Protein deficiency occurs when your intake does not meet your body’s needs. Protein deficiency affects about one billion people globally [1]. Certain people in developed countries are likewise vulnerable. This includes people with an unbalanced diet, as well as confined elderly and hospitalised patients [2], [3]. While real protein deficiency is uncommon in the Western world, some people are consuming very little of it.

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    Insufficient protein intake may cause long-term changes in body composition, such as muscle loss. Kwashiorkor is the most severe form of protein deficiency. It is more common in children in developing countries where starvation and unbalanced nutrition are common. Protein deficiency can affect every aspect of physiological function. As a result, it is linked to a variety of symptoms. Some of these symptoms may appear even when protein deficiency is mild.

    Protein deficiency happens when your intake falls short of your body’s needs. Low protein intake may cause long-term changes in body composition, such as muscle loss. The most severe form of protein deficiency is kwashiorkor. It is especially common in children in developing countries where there is widespread malnutrition.

    Here are 7 risks and symptoms of protein deficiency.

    1. Loss of Lean Muscle Mass

    Your muscles are the greatest protein reservoir in your body. The body takes the protein from skeletal muscles to maintain more important tissue to functions. As a result, the lack of protein over time leads to muscle loss. Even mild protein deficiency can cause muscle loss in the elderly. One study in elderly men and women showed that muscle loss among those who ate low protein diet was higher [4]. Other studies show that an increased intake of protein can delay muscle degeneration that comes with old age [5].

    A higher protein intake can help prevent the onset of muscle loss in old age. According to one study, a low protein diet increases the likelihood of muscle loss in aged men and women.

    2. Risk of Bone Fractures

    Muscle tissues are not the only thing that is affected by protein deficiency. The bones are also at risk. Not eating enough protein can weaken your bones and increase bone fracture risks [6], [7], [8]. One study found a higher intake of the protein can lower risk of hip fractures [9]. The study associate high protein diet with a reduced risk of fracture by 69%, and the highest outcomes were linked to the animal-protein sources. Another study of hip fractures in postmenopausal women found that taking 20 grams of protein supplements per day for half a year reduced bone loss by 2.3% [10].

    Taking 20g of protein supplements per day for half a year prevented bone loss by 2.3% in postmenopausal women. Ingesting animal protein sources can reduce the incidence of bone fracture by 69%.

    3. Stunted Growth

    Protein not only helps build muscle and bone mass, but it is also important to the overall growth of the body. Protein deficiency is detrimental to children whose growing bodies need a steady supply. Stunting is the most common sign of malnutrition in childhood. Stunted growth affected about 161 million children only in 2013 [11]. Studies show a strong correlation between low intake of protein and stunt growth [12], [13]. Kwashiorkor is also the major culprit behind the stunted growth of children, which is usually caused by malnutrition [14].

    Protein deficiency is dangerous for children, whose growing bodies require a consistent supply. Only in 2013, around 161 million children experienced stunted growth.

    4. Skin, Hair, and Nail Problems

    Protein deficiency also affects the skin, hair, and nails. In children, for example, flaky split skin and depigmented skin patches or redness are the symptoms of kwashiorkor [15], [16]. Also, hair thinning, fading hair color, hair loss, and brittle nails are also signs of protein deficiency [17], [18]. However, unless you have a serious protein deficiency, such signs would occur.

    Protein deficiency can cause hair thinning, fading hair colour, hair loss, and brittle nails. Such symptoms would not develop unless you have a severe protein deficiency.

    5. Edema

    Edema, a swollen and puffy skin, which is usually a symptom of kwashiorkor. Scientists believe low levels of human serum albumin, the most abundant protein in the blood’s fluid portion, or blood plasma cause it [19]. One of the major function of albumin is to maintain oncotic pressure that brings fluid into the blood flow. Albumin thus avoids the accumulation of excessive amounts of fluid in tissues or other body areas. Severe protein deficiency leads to lower oncotic stress because of reduced levels of human serum albumin. As a result, water accumulates and induces swelling of tissues.

    Protein deficiency can cause a fluid buildup within the abdominal cavity for the same cause. A bloated belly is a symptom of kwashiorkor.

    6. Greater Calorie Intake

    If your intake of protein is insufficient, your body will try to restore your protein stores by increasing your appetite and motivating you to find something to eat [20], [21]. But a protein deficiency does not trigger the appetite to eat, at least not for everyone. It can increase the appetite for sweet foods that appear to be high in protein in some people [22]. Low intake of protein can cause weight gain and obesity, a concept known as protein leverage hypothesis [23].

    Not all studies support the hypothesis, but protein is satiating more than fat and carbs [24], [25]. This is part of why increased intake of protein can reduce the overall intake of calories and encourage weight loss [26], [27]. When you feel hungry all the time and have trouble monitoring your calorie intake, try to add some lean protein to each meal.

    Protein deficiency can lead to weight gain and obesity. When you’re constantly hungry and having difficulties keeping track of your calorie intake, try adding extra lean protein to each meal.

    7. Fatty Liver

    A fatty liver or fat accumulation in liver cells is another common symptom of kwashiorkor [28]. This condition will lead to fatty liver disease if left untreated, causing inflammation, hepatic scarring, and possibly liver failure. Among obese people, fatty liver is a common condition, especially for those who drink a lot of alcohol [29], [30]. Yet, studies suggest that impaired synthesis of fat-transporting proteins, known as lipoproteins, may lead to the condition [31].

    Another symptom of kwashiorkor is a fatty liver or fat accumulation in liver cells. If left untreated, this condition will develop to fatty liver disease. A deficiency in fat-transporting proteins known as lipoproteins may cause the condition.

    Does Protein Deficiency Affect Immunity?

    Protein deficiency can impair the immune system. Impaired immune function can increase the risk of infection [32], [33]. For example, one study in mice found that a more serious influenza infection followed a diet containing only 2% protein, compared to 18% protein diet [34]. A low intake of protein can actually increase the risk of infection. In another nine weeks study of older women found that their immune response was reduced after a low-protein diet [35].

    Protein deficiency can actually raise the risk of infection.

    How Much Protein Do I Need?

    The recommended daily allowance for each pound of body weight is 0.4 grams (0.8 grams per kg). Scientists estimate that for most people, this should be enough. For a person weighing 165 pounds (75 kg), should take 66 grams of protein per day. For athletes, the American College of Sports Medicine advises a daily protein consumption of 0.5 to 0.6 gram per pound of body weight (1.2–1.4 gram per kg), which should be enough for muscle maintenance and training recovery [36].

    However, scientists disagree on how much is sufficient. Athletes should consume 0.9 gram of protein per pound of body weight (2 grams per kg) daily [37]. Just like athletes, older people appear to have higher protein requirements. While the RDA for elderly and young adults is currently the same, research show that it is underestimated and should be increased to 0.5 to 0.7 gram per pound of body weight (1.2–1.5 grams per kg) for older people [38], [39].

    For a normal person, weighing 165 pounds (75 kg) should consume 66 grams of protein per day. The recommended daily requirement for each pound of body weight is 0.4 grams (0.8 gram per kg). Athletes and older people appear to have increased protein requirements.

    What Foods are High in Protein?

    High-protein foods include meats, poultry, and fish, and dairy products, tofu, grains, other vegetables and fruits, eggs, legumes, nuts, and seeds. Eating a variety of protein foods will increase the intake of nutrients. Some healthy sources of protein are lean and low-fat poultry and food. For vegetarians, there are choices such as lentils, peas, beans, nuts, grains, and refined soy products.


    Most of the muscles, skin, hair, bones, and blood are protein. Protein deficiency, therefore, has a wide range of symptoms. Serious protein deficiency in children can cause swelling, fatty liver, skin degeneration, increase infection severity, and stunt growth.

    Suggested article: 10 proven health benefits of whey protein backed by science.


    1. Wu G, Fanzo J, Miller DD, Pingali P, Post M, Steiner JL, Thalacker-Mercer AE. Production and supply of high-quality food protein for human consumption: sustainability, challenges, and innovations. Ann N Y Acad Sci. 2014 Aug;1321:1-19. doi: 10.1111/nyas.12500. PMID: 25123207.
    2. Dorner B, Friedrich EK, Posthauer ME; American Dietetic Association. Position of the American Dietetic Association: individualized nutrition approaches for older adults in health care communities. J Am Diet Assoc. 2010 Oct;110(10):1549-53. doi: 10.1016/j.jada.2010.08.022. Erratum in: J Am Diet Assoc. 2010 Dec;110(12):1941. PMID: 20882714.
    3. Dodson S, Baracos VE, Jatoi A, Evans WJ, Cella D, Dalton JT, Steiner MS. Muscle wasting in cancer cachexia: clinical implications, diagnosis, and emerging treatment strategies. Annu Rev Med. 2011;62:265-79. doi: 10.1146/annurev-med-061509-131248. PMID: 20731602.
    4. Campbell WW, Trappe TA, Jozsi AC, Kruskall LJ, Wolfe RR, Evans WJ. Dietary protein adequacy and lower body versus whole body resistive training in older humans. J Physiol. 2002 Jul 15;542(Pt 2):631-42. doi: 10.1113/jphysiol.2002.020685. PMID: 12122158; PMCID: PMC2290421.
    5. Wiswell RA, Hawkins SA, Jaque SV, Hyslop D, Constantino N, Tarpenning K, Marcell T, Schroeder ET. Relationship between physiological loss, performance decrement, and age in master athletes. J Gerontol A Biol Sci Med Sci. 2001 Oct;56(10):M618-26. doi: 10.1093/gerona/56.10.m618. PMID: 11584034.
    6. Kerstetter JE, O’Brien KO, Insogna KL. Low protein intake: the impact on calcium and bone homeostasis in humans. J Nutr. 2003 Mar;133(3):855S-861S. doi: 10.1093/jn/133.3.855S. PMID: 12612169.
    7. Bonjour JP, Schurch MA, Rizzoli R. Nutritional aspects of hip fractures. Bone. 1996 Mar;18(3 Suppl):139S-144S. doi: 10.1016/8756-3282(95)00494-7. PMID: 8777079.
    8. Heaney RP. Age considerations in nutrient needs for bone health: older adults. J Am Coll Nutr. 1996 Dec;15(6):575-8. doi: 10.1080/07315724.1996.10718632. PMID: 8951734.
    9. Munger RG, Cerhan JR, Chiu BC. Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women. Am J Clin Nutr. 1999 Jan;69(1):147-52. doi: 10.1093/ajcn/69.1.147. PMID: 9925137.
    10. Schürch MA, Rizzoli R, Slosman D, Vadas L, Vergnaud P, Bonjour JP. Protein supplements increase serum insulin-like growth factor-I levels and attenuate proximal femur bone loss in patients with recent hip fracture. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 1998 May 15;128(10):801-9. doi: 10.7326/0003-4819-128-10-199805150-00002. PMID: 9599191.
    11. de Onis M, Branca F. Childhood stunting: a global perspective. Matern Child Nutr. 2016 May;12 Suppl 1(Suppl 1):12-26. doi: 10.1111/mcn.12231. PMID: 27187907; PMCID: PMC5084763.
    12. Arnold GL, Vladutiu CJ, Kirby RS, Blakely EM, Deluca JM. Protein insufficiency and linear growth restriction in phenylketonuria. J Pediatr. 2002 Aug;141(2):243-6. doi: 10.1067/mpd.2002.126455. PMID: 12183721.
    13. Kindt E, Lunde HA, Gjessing LR, Halvorsen S, Lie SO. Fasting plasma amino acid concentrations in PKU children on two different levels of protein intake. Acta Paediatr Scand. 1988 Jan;77(1):60-6. doi: 10.1111/j.1651-2227.1988.tb10598.x. PMID: 3369307.
    14. Waterlow JC. Protein-energy malnutrition: the nature and extent of the problem. Clin Nutr. 1997 Mar;16 Suppl 1:3-9. doi: 10.1016/s0261-5614(97)80043-x. PMID: 16844615.
    15. McLaren DS. Skin in protein energy malnutrition. Arch Dermatol. 1987 Dec;123(12):1674-1676a. PMID: 3120652.
    16. Rogers AS, Shaughnessy KK, Davis LS. Dermatitis and dangerous diets: a case of kwashiorkor. JAMA Dermatol. 2014 Aug;150(8):910-1. doi: 10.1001/jamadermatol.2013.10328. PMID: 24807070.
    17. Rushton DH. Nutritional factors and hair loss. Clin Exp Dermatol. 2002 Jul;27(5):396-404. doi: 10.1046/j.1365-2230.2002.01076.x. PMID: 12190640.
    18. GODWIN KO. Skin, hair and nail in protein malnutrition. World Rev Nutr Diet. 1961;3:103-28. PMID: 13963281.
    19. Coulthard MG. Oedema in kwashiorkor is caused by hypoalbuminaemia. Paediatr Int Child Health. 2015 May;35(2):83-9. doi: 10.1179/2046905514Y.0000000154. Epub 2014 Sep 16. PMID: 25223408; PMCID: PMC4462841.
    20. Gosby AK, Conigrave AD, Raubenheimer D, Simpson SJ. Protein leverage and energy intake. Obes Rev. 2014 Mar;15(3):183-91. doi: 10.1111/obr.12131. Epub 2013 Oct 28. PMID: 24588967.
    21. Apolzan JW, Carnell NS, Mattes RD, Campbell WW. Inadequate dietary protein increases hunger and desire to eat in younger and older men. J Nutr. 2007 Jun;137(6):1478-82. doi: 10.1093/jn/137.6.1478. PMID: 17513410; PMCID: PMC2259459.
    22. Griffioen-Roose S, Mars M, Siebelink E, Finlayson G, Tomé D, de Graaf C. Protein status elicits compensatory changes in food intake and food preferences. Am J Clin Nutr. 2012 Jan;95(1):32-8. doi: 10.3945/ajcn.111.020503. Epub 2011 Dec 7. PMID: 22158729; PMCID: PMC3238463.
    23. Simpson SJ, Raubenheimer D. Obesity: the protein leverage hypothesis. Obes Rev. 2005 May;6(2):133-42. doi: 10.1111/j.1467-789X.2005.00178.x. PMID: 15836464.
    24. Griffioen-Roose S, Mars M, Siebelink E, Finlayson G, Tomé D, de Graaf C. Protein status elicits compensatory changes in food intake and food preferences. Am J Clin Nutr. 2012 Jan;95(1):32-8. doi: 10.3945/ajcn.111.020503. Epub 2011 Dec 7. PMID: 22158729; PMCID: PMC3238463.
    25. Leidy HJ, Clifton PM, Astrup A, Wycherley TP, Westerterp-Plantenga MS, Luscombe-Marsh ND, Woods SC, Mattes RD. The role of protein in weight loss and maintenance. Am J Clin Nutr. 2015 Jun;101(6):1320S-1329S. doi: 10.3945/ajcn.114.084038. Epub 2015 Apr 29. PMID: 25926512.
    26. Eisenstein J, Roberts SB, Dallal G, Saltzman E. High-protein weight-loss diets: are they safe and do they work? A review of the experimental and epidemiologic data. Nutr Rev. 2002 Jul;60(7 Pt 1):189-200. doi: 10.1301/00296640260184264. PMID: 12144197.
    27. Westerterp-Plantenga MS. The significance of protein in food intake and body weight regulation. Curr Opin Clin Nutr Metab Care. 2003 Nov;6(6):635-8. doi: 10.1097/00075197-200311000-00005. PMID: 14557793.
    28. Doherty JF, Adam EJ, Griffin GE, Golden MH. Ultrasonographic assessment of the extent of hepatic steatosis in severe malnutrition. Arch Dis Child. 1992 Nov;67(11):1348-52. doi: 10.1136/adc.67.11.1348. PMID: 1471885; PMCID: PMC1793750.
    29. Hamaguchi M, Kojima T, Takeda N, Nakagawa T, Taniguchi H, Fujii K, Omatsu T, Nakajima T, Sarui H, Shimazaki M, Kato T, Okuda J, Ida K. The metabolic syndrome as a predictor of nonalcoholic fatty liver disease. Ann Intern Med. 2005 Nov 15;143(10):722-8. doi: 10.7326/0003-4819-143-10-200511150-00009. PMID: 16287793.
    30. Lieber CS. Alcoholic fatty liver: its pathogenesis and mechanism of progression to inflammation and fibrosis. Alcohol. 2004 Aug;34(1):9-19. doi: 10.1016/j.alcohol.2004.07.008. PMID: 15670660.
    31. Badaloo A, Reid M, Soares D, Forrester T, Jahoor F. Relation between liver fat content and the rate of VLDL apolipoprotein B-100 synthesis in children with protein-energy malnutrition. Am J Clin Nutr. 2005 May;81(5):1126-32. doi: 10.1093/ajcn/81.5.1126. PMID: 15883438.
    32. Li P, Yin YL, Li D, Kim SW, Wu G. Amino acids and immune function. Br J Nutr. 2007 Aug;98(2):237-52. doi: 10.1017/S000711450769936X. Epub 2007 Apr 3. PMID: 17403271.
    33. Schaible UE, Kaufmann SH. Malnutrition and infection: complex mechanisms and global impacts. PLoS Med. 2007 May;4(5):e115. doi: 10.1371/journal.pmed.0040115. PMID: 17472433; PMCID: PMC1858706.
    34. Taylor AK, Cao W, Vora KP, De La Cruz J, Shieh WJ, Zaki SR, Katz JM, Sambhara S, Gangappa S. Protein energy malnutrition decreases immunity and increases susceptibility to influenza infection in mice. J Infect Dis. 2013 Feb 1;207(3):501-10. doi: 10.1093/infdis/jis527. Epub 2012 Sep 4. PMID: 22949306.
    35. Castaneda C, Charnley JM, Evans WJ, Crim MC. Elderly women accommodate to a low-protein diet with losses of body cell mass, muscle function, and immune response. Am J Clin Nutr. 1995 Jul;62(1):30-9. doi: 10.1093/ajcn/62.1.30. PMID: 7598064.
    36. Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Med Sci Sports Exerc. 2016 Mar;48(3):543-68. doi: 10.1249/MSS.0000000000000852. Erratum in: Med Sci Sports Exerc. 2017 Jan;49(1):222. PMID: 26891166.
    37. Campbell B, Kreider RB, Ziegenfuss T, La Bounty P, Roberts M, Burke D, Landis J, Lopez H, Antonio J. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2007 Sep 26;4:8. doi: 10.1186/1550-2783-4-8. PMID: 17908291; PMCID: PMC2117006.
    38. Rafii M, Chapman K, Elango R, Campbell WW, Ball RO, Pencharz PB, Courtney-Martin G. Dietary Protein Requirement of Men >65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement. J Nutr. 2015 Apr 1;146(4):681-687. doi: 10.3945/jn.115.225631. PMID: 26962173.
    39. Bauer J, Biolo G, Cederholm T, Cesari M, Cruz-Jentoft AJ, Morley JE, Phillips S, Sieber C, Stehle P, Teta D, Visvanathan R, Volpi E, Boirie Y. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc. 2013 Aug;14(8):542-59. doi: 10.1016/j.jamda.2013.05.021. Epub 2013 Jul 16. PMID: 23867520.
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    Naeem Durrani BSc
    I am a retired pharmacist, nutrition expert, journalist, and more. My interests include medical research, and the scientific evidence around effective wellness practices, which empower people to transform their lives.
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