Open access peer-reviewed chapter

Unintentional Weight Loss

Written By

Naim Abu Freha

Reviewed: February 5th, 2018 Published: November 5th, 2018

DOI: 10.5772/intechopen.74860

Chapter metrics overview

933 Chapter Downloads

View Full Metrics


Unintentional weight loss (UWL) is a common symptom, particularly among older patients. In one site, patients with UWL have increased morbidity and mortality; in the other site, the prognosis of the patients is related to primary cause of the UWL. The differential diagnosis of the underlying diseases leading to UWL is broad and includes both malignant and nonmalignant gastrointestinal (GI) diseases, as well as endocrine, infectious, cardiopulmonary, and psychiatric disorders and side effects of medications. Patients with UWL should be investigated. The diagnostic approach to patients with UWL includes comprehensive medical history, physical examination, laboratory testing, imaging, and endoscopy. The imaging and endoscopy should be targeted according to the symptom, physical examination findings, and laboratory results. The treatment of UWL should be targeted to the primary disease causing weight loss. Non-pharmacologic nutrition intervention is the important treatment, and some pharmacologic treatment could be helpful in part of the patients.


  • unintentional
  • unexplained
  • weight loss
  • diagnosis
  • gastrointestinal disorders
  • gastrointestinal malignancy
  • endoscopic investigation
  • morbidity

1. Introduction

The most accepted and most frequently used definition of significant unintentional weight loss (UWL) is the loss of at least 5% of usual body weight over 6–12 months [1, 2]. The weight loss is unintentional and unexplained and should be further investigated.

UWL is a common phenomenon among older adults, with an annual incidence of approximately 13% [3]. Other epidemiologic studies have shown that about 15–20% of elderly patients experience weight loss and this prevalence increases in high-risk patients [4, 5, 6].

The body weight changes during the life cycle include increasing of the body weight during early adulthood until the fifth to sixth decade of life, the reason for this increase is the increasing of the body [7]. But regarding the lean body mass, there is a decline at a rate of 0.3 kg/year, beginning in the third decade. Total body mass remains stable from the fifth decade until about age 70; it then slowly decreases at a rate of only 0.1–0.2 kg/year [7].

Different Inflammatory cytokines and interleukins are involved in the pathogenesis of UWL. Tumor necrosis factor-α (TNF-α), interleukin-1β, and interleukin-6 have been implicated in cachexia and weight loss [3].

One of these important mediators is the TNF-α, which considered to be a primary mediator of the muscle wasting of cachexia [3]. Cytokines may act both centrally and peripherally; the most important effects include inhibiting feeding behavior, by decreasing gastric motility, gastric emptying, and intestinal motility and by modifying gastric secretion [3].


2. Risk factors of UWL

On the basis of several studies, different risk factors were found for UWL among adults older than 65 years, subgrouped as:

  1. Physiologic factors: acute illness, hospitalization, exacerbation of chronic diseases, dementia, constipation, pressure ulcers, daily pain, medications, compromised motility, recurrent falls, eating and swallowing problems, reduced appetite, low food intake, thirst, serum albumin <35 g/l, and total cholesterol <4.2 mmol/l were found to be factors for UWL [8, 9, 10, 11, 12, 13].

  2. Psychological factors: depression and bereavement [11, 13].

  3. Social factors: reduced social activity and low income [9, 10].


3. Unintentional weight loss morbidity, mortality, and prognosis

Increased fracture risk has been associated with weight loss in postmenopausal women; significant association was found between unintentional weight loss and fracture of the hip, spine, and clavicle within 1 year of weight loss; and these associations were still present at 5 years [14]. Another study showed that unexplained weight loss may be important predictors of suicide [15].

Functional decline, infections, decubitus ulcers, exacerbation of cognitive and mood disorders, and increased use of acute and long-term care facilities are important clinical consequences of the UWL [16].

In general, the result of different studies has shown that UWL is associated with mortality rates ranging between 9 and 38% in elderly adults [17, 18, 19, 20].

UWL is a nonspecific condition that may be caused by a multitude of medical and psychiatric disorders. Consequently, its natural history varies considerably depending on the underlying cause.

On the basis of study of Marton et al., 25% of the patients died within 1 year, and another 15% continued to lose weight or deteriorate in function [17].

Most patients who did poorly had advanced cardiopulmonary disease or cancer. In another study 51 of the 104 cancer patients had disseminated disease at diagnosis; median survival of the cancer patients was just 2 months; and only 9 lived longer than 1 year [21].

Most patients without a physical cause of weight loss fared well, survivors do well. Most either maintain or gain weight, but only a minority return to their baseline weight [17, 20, 22].


4. Differential diagnosis of UWL

The differential diagnosis of the underlying diseases leading to UWL is broad and includes both malignant and benign gastrointestinal (GI) diseases, as well as endocrine, infectious, cardiopulmonary, and psychiatric disorders [20]. GI disorders are commonly associated with UWL, with gastric and colon cancer, celiac disease, peptic ulcers, and inflammatory bowel diseases being the leading causes [19].

The list of medications causing weight loss includes a different kinds of medications, which used for treatment of cardiac, neurologic and psychiatric diseases, and tablets used for treatment of diabetes mellitus and pain management can also cause weight loss. Side effects of different medications could include anorexia, dry mouth, dysgeusia, dysphagia, nausea, and vomiting, and the result of these side effects will be lowering the daily oral intake and weight loss [8, 23]. Despite the long list of weight loss causes, in about 5-36% of the patient the cause of the UWL is unknown [2].

However, among elderly patients the 9 Ds could help us to focus of the most common reasons among this group, dementia, depression, disease (acute or chronic), dysphagia, dysgeusia, diarrhea, drug, dentition, and dysfunction (functional disability) [24].

The most common causes of unintentional weight loss are summarized in Table 1.

Gastrointestinal diseases
Esophageal ulcer
Moderate/severe esophagitis
Esophageal stricture
Esophageal cancer
Moderate/severe gastritis
Peptic ulcer
Gastric cancer
Gastric lymphoma
Celiac disease
Malabsorption syndromes
Inflammatory bowel disease
Colon cancer
Chronic pancreatitis
Pancreatic cancer
Hepatocellular carcinoma
Endocrine diseases
Diabetes mellitus
Infectious diseases
Acquired immunodeficiency syndrome (AIDS)
Cardiopulmonary diseases
Congestive heart disease
Chronic lung disease
Lung cancer
Psychiatric disease Depression
Hematologic disease Lymphoma
Renal chronic kidney disease
Inflammatory non-infection disease
Connective tissue disease
Temporal arteritis
Other Medications
Dental and oral health problem
Laryngeal cancer
Pharyngeal cancer
Advanced metastatic cancers

Table 1.

The most common diseases causing unintentional weight loss.


5. UWL and cancer

When evaluating patients with UWL, detection of an underlying malignancy is of the greatest concern. A large list of different cancers could cause unintentional weight loss, not only in gastrointestinal cancer but in other malignancies too.

Furthermore, any type of malignant neoplasm can be the cause of weight loss in the advanced metastatic stage. The most common neoplasms causing weight loss are included in Table 1.

The reported prevalence of gastrointestinal (GI) malignancies in patients with UWL varies significantly between studies, with rates of 6–38% in different publications [17, 18, 20, 21, 25]. GI malignancy is an important and a feared cause of UWL. Different reports have shown a low GI malignancy rates of 6.6–12% in patients with UWL depending on the diagnostic modality used [20, 26], and another study found 57 (3.7%) and 24 (4.3%) cases of malignancy in the upper and lower GI tract, respectively [27]. Additional study showed that UWL alone was not associated with colorectal cancer among patients who underwent colonoscopy [28].

The differences between malignancy detection rates found in the different studies in the literature are mainly a result of variations in study design, population diversity, and the lack of a standardized definition for what is considered meaningful endoscopic findings in the context of UWL across different studies.


6. Diagnostic approach to patients with UWL

Patients with UWL must be investigated, and it poses a diagnostic challenge for the clinician in a large part of the patients because of the broad range of etiologic possibilities. To date, no guidelines have been published for the evaluation and management of patients with UWL; when evaluating patients with UWL, practitioners need to exercise careful judgment in terms of the extent of the initial workup and, if additional investigations are required, in choosing the most appropriate diagnostic modalities. However, the workup should include simple and noninvasive tests in the early investigation stage, and additional invasive tests should be directed to specific organ later. Common practices include detailed medical history, physical examination, laboratory testing, fecal occult blood testing, and imaging as part of the baseline evaluation [2, 23, 24, 29], and endoscopy should be part of the investigation among patients with gastrointestinal symptoms or if the baseline evaluation was normal.

6.1. Medical history

Comprehensive detailed medical history is the first and important step. Information regarding other symptoms, particularly gastrointestinal, hematological, and psychiatric symptoms, and symptoms like abdominal pain, rectal bleeding, change of bowel habits, vomiting, anemia, night sweating, and depression should be part of the medical history taking.

Asking about smoking, alcohol abuse, medications, psychosocial factors, dietary history, travel, and sexual risk behavior should be part of taking medical history [2]. Further investigation could be directed by specific symptoms.

6.2. Physical examination

Comprehensive whole-body examination should be done and focused on abdominal mass, organomegaly, lymphadenopathy, breast mass, prostate enlargement, sign of wasting, and weight loss. The importance of mouth examination particularly among elderly adults is to exclude dental problem, dry mouth, or other lesions that may interfere chewing and swallowing.

6.3. Laboratory testing

Laboratory testing is an important part of the UWL investigation, abnormalities of results could be a direction to the cause of the weight loss and then further specific investigation should be the next step. The important laboratory tests should be included in the baseline investigation are: complete blood count, liver, kidney, thyroid function tests, serum glucose, lactace dehydrogenase, C-reactive protein, electrolytes, albumin, iron studies, urinalysis and fecal occult blood test.

6.4. Imaging

Chest radiography and abdominal ultrasonography are included in the baseline investigation on unintentional weight loss. However, there are no published dates regarding the diagnostic yield of computer tomography among patients with UWL. For patients, who underwent baseline investigation, and there is no direction to diagnosis, further investigation with chest, abdominal, and pelvic contrast computer tomography will be appropriate; the advantages of computer tomography are imaging of chest, mediastinum, lymphadenopathy, and better imaging of the abdomen and pelvis including organs like pancreas and the bowel.

6.5. Endoscopy

Gastrointestinal disorders may account for up to 25–30% of the cases of UWL [20, 25]. Unfortunately, data on the diagnostic yield of endoscopy in UWL are scant [26, 30]. The role of endoscopic evaluation in this framework remains controversial. Although some authors include esophagogastroduodenoscopy (EGD) as part of the initial workup of all patients with UWL, others argue that it should be reserved for those who initially present with GI symptoms or signs [1, 24]. However, little is known about the diagnostic yield of endoscopy in the context of UWL. A small study from the non-English literature has showed that gastroscopy can lead to a definite diagnosis in more than half of the cases [31]. However, this study was carried out in a small cohort of elderly (mean age, 80 years) in-patients; thus, its conclusions may not be generalizable to the broader population of patients with UWL. Another study found that the yield of endoscopy for the evaluation of UWL was not negligible. Of 2098 procedures performed in 1843 patients, endoscopic findings that could explain weight loss were found in 10% of EGD and 6% of colonoscopies [27]. However, the rate of detection of clinical significant endoscopic finding in both upper and lower endoscopies was significantly lower in patients who had no other indications for endoscopy besides weight loss [27].

Patients, who have gastrointestinal symptoms in addition to the UWL and patients with normal baseline evaluation, should undergo endoscopy.


7. Age and UWL

A slow decrease in body mass (0.1–0.2 kg/year) usually occurs in association with normal aging [32]. However, beyond this naturally occurring process, elderly patients are more prone to present with clinically significant weight loss [7, 16]. Accurate diagnosis of the underlying cause for weight loss in this population is important as the natural history of this condition at an older age is less favorable [33].

Approximately 60% of the patients in both the gastroscopy and colonoscopy cohorts were 65 years of age and older [27]. Furthermore, age older than 65 years or more was strongly associated with detection of any pathologic endoscopic findings, whereas 60% of the clinical significant endoscopic finding by gastroscopy and 50% of those diagnosed by colonoscopy were found in patients in this age group. Different studies showed increased mortality among patients older than age 65 with UWL [16, 34, 35].


8. Treatment of UWL

The treatment of UWL should be targeted to the primary disease causing the weight loss. In cases, in which no organic or psychiatric disease was found, the treatment has to be individualized and target patient’s nutrition status, risk factors, and social conditions.

Patient’s medications must be reviewed and if any medication is suspected to be contributed to the weight loss should be discontinued and replaced by an alternative drug.

Nutritional interventions as a non-pharmacologic treatment were investigated in several studies. The hallmarks of nutritional intervention should include optimizing food intake, oral nutritional supplements, and adding multivitamins. The patients should have been encouraged to eat small and often meals, eating favorite food, avoiding gas-producing foods, and taking multiple vitamins daily. The compliance of patients to the different diets is an important issue.

Consultation, support, and follow-up by a dietician are important parts of the management of patients with UWL.

Physical training has a positive impact of the increasing weight among community-dwelling individual. Regular exercise (particularly resistance training) is also recommended for frail elderly patients because it stimulates appetite and prevents sarcopenia.

Different small trials examined pharmacologic treatment of patients with UWL.

The evidence supporting any pharmacologic agent for the treatment of weight loss is limited to mostly small and uncontrolled studies.

The effect of different appetite stimulants and anabolic medications of UWL was examined. Some of them showed a trend of weight gain; however, most of the medications have significant side effects, particularly in frail elderly people. Megestrol acetate, dronabinol, ornithine oxoglutarate, cyproheptadine, and human growth hormone were examined in few studies.


9. Conclusions

Unintentional weight loss is a common health problem with increase mortality with a broad spectrum of differential diagnosis. The diagnostic approach should be targeted according the medical history, physical examination, and laboratory results.


Conflict of interest

There are no conflicts in interest to be reported.


  1. 1. Bouras EP, Lange SM, Scolapio JS. Rational approach to patients with unintentional weight loss. Mayo Clinic Proceedings. 2001;76(9):923. DOI: 10.4065/76.9.923
  2. 2. Vanderschueren S, Geens E, Knockaert D, Bobbaers H. The Diagnostic spectrum of unintentional weight loss. European Journal of Internal Medicine. 2005;16:160-164. DOI: 10.1016/j.ejim.2005.01.004
  3. 3. Ruscin JM, Page RL II, Yeager BF, Wallace JI. Tumor necrosis factor alpha and involuntary weight loss in elderly, community dwelling adults. Pharmacotherapy. 2005;25:313-319
  4. 4. Newman AB, Yanez D, Harris T, Duxbury A, Enright PL, Fried LP. Weight change in old age and its association with mortality. Journal of the American Geriatrics Society. 2001;49(10):1309-1318
  5. 5. Deeg DJ, Miles TP, Van Zonneveld RJ, Curb JD. Weight change, survival time and cause of death in Dutch elderly. Archives of Gerontology and Geriatrics. 1990;10(1):97-111
  6. 6. De Groot CP, Perdigao AL, Deurenberg P. Longitudinal changes in anthropometric characteristics of elderly Europeans. SENECA Investigators. European Journal of Clinical Nutrition. 1996;50(Suppl. 2):S9-S15
  7. 7. Wallace JI, Schwartz RS. Epidemiology of weight loss in humans with special reference to wasting in the elderly. International Journal of Cardiology. 2002;85:15-21. DOI: 10.1016/s0167-5273(02)00246-2
  8. 8. Stajkovic S, Aitken EM, Holroyd-Leduc J. Unintentional weight loss in older adults. CMAJ. 2011;183(4):443-449. DOI: 10/1503/cmaj.101471
  9. 9. Sorbye LW, Schroll M, Finne Soveri H, Jonsson PV, Topinkova E, Ljunggren G, Bernabei R. Unintended weight loss in the elderly living at home: The aged in-Home Care Project (AdHOC). The Journal of Nutrition, Health & Aging. 2008;12:10-16
  10. 10. Bartlett BJ. Characterization of anorexia in nursing home patients. Educational Gerontology. 1990;16:591-600
  11. 11. Wright BA. Weight loss and weight gain in a nursing home: A prospective study. Geriatric Nursing. 1993;14:156-159
  12. 12. Berkhout AM, Cools HJ, van Houwelingen HC. The relationship between difficulties in feeding oneself and loss of weight in nursing-home patients with dementia. Age and Ageing. 1998;27:637-641
  13. 13. Gilmore SA, Robinson G, Posthauer ME, Raymond J. Clinical indicators associated with unintentional weight loss and pressure ulcers in elderly residents of nursing facilities. Journal of the American Dietetic Association. 1995;95:984-992
  14. 14. Compston J, Wyman A, FitzGerald G, Adachi J, Chapurlat R, Cooper C, Díez-Pérez A, Gehlbach S, Greenspan S, Hooven F, LaCroix A, March L, Netelenbos C, Nieves J, Pfeilschifter J, Rossini M, Roux C, Saag K, Siris E, Silverman S, Watts N, Anderson F. Increase in fracture risk following unintentional weight loss in postmenopausal women: The global longitudinal study of osteoporosis in women. Journal of Bone and Mineral Research. 2016;31(7):1466-1472. DOI: 10.1002/jbmr.2810
  15. 15. Elovainio M, Shipley M, Ferrie J, Gimeno D, Vahtera J, Marmot M, Kivimäki M. Obesity, unexplained weight loss and suicide: The original Whitehall study. Journal of Affective Disorders. 2009;116(3):218-221. DOI: 10.1016/j.jad.2008.12.002
  16. 16. Wallace JI, Schwartz RS, LaCroix AZ, Uhlmann RF, Pearlman RA. Involuntary weight loss in older outpatients: Incidence and clinical significance. Journal of the American Geriatrics Society. 1995;43:329-337. DOI: 10.1111/j.1532-5415.1995.tb05803.x
  17. 17. Marton KI, Sox HC Jr, Krupp Jr. Involuntary weight loss: Diagnostic and prognostic significance. Annals of Internal Medicine. 1981;95:568-574. DOI: 10.7326/0003-4819-95-5-568
  18. 18. Rabinovitz M, Pitlik SD, Leifer M, Garty M, Rosedfeld JB. Unintentional weight loss: A retrospective analysis of 154 cased. Archives of Internal Medicine. 1986;146:186-187. DOI: 10.1001/archinte.146.1.186
  19. 19. Bilbao-Garay J, Barba R, Losa-Garcia L, Martin H, Carcia de Casasola G, Castilla V, Conzaelz-Anglada I, Espinosa A, Guijarro. Assessing clinical probability of organic disease in patients with involuntary weight loss: A simple score. European Journal of Internal Medicine. 2002;13:240-245. DOI: 10.1016/S0953-6205(02)00032-8
  20. 20. Lankisch PG, Grezmann M, Grezmann JF, Lehnick D. Unintentional weight loss: Diagnosis and prognosis. The first prospective follow-up study a secondary referral centre. Journal of Internal Medicine. 2001;249:41-46. DOI: 10.1046/j.1365-2796.2001.00771.x
  21. 21. Hernandez JL, Riancho JA, Matorras P, Gonzalez-Macias J. Clinical evaluation for cancer in patients with involuntary weight loss without specific symptoms. The American Journal of Medicine. 2003;114:631-637. DOI: 10.1016/s0002-9343(03)00115-3
  22. 22. Levine MA. Unintentional weight loss in the ambulatory setting: Etiologies and outcomes. Clinical Research. 1991;39:580A
  23. 23. Alibhai SM, Greenwood C, Payette H. An approach to the management of unintentional weight loss in the elderly. CMAJ. 2005;172:773-780. DOI: 10.1503/cmaj.1031527
  24. 24. McMinn J, Steel C, Bowman A. Investigation and management of unintentional weight loss in older adults. BMJ. 2011;29:342. DOI: 10.1136/bmj.d1732
  25. 25. Metalidis C, Knockaert DC, Bobbaers H, Vanderschueren S. Involuntary weight loss, does a negative baseline evaluation provide adequate reassurance? European Journal of Internal Medicine. 2008;19:345-349. DOI: 10.1016/j.ejim.2007.09.019
  26. 26. Mummadi RR, Lee GH, Amar NK, Raju GS. Diagnostic yield of endoscopy in patients with unexplained weight loss. Gastrointestinal Endoscopy. 2007;65:5AB357. DOI: 10.1016/j.gie.2007.03.920
  27. 27. Abu-Freha N, Lior Y, Shoher S, Novack V, Fich A, Rosenthal A, Etzion O. The yield of endoscopic investigation for unintentional weight loss. European Journal of Gastroenterology & Hepatology. 2017 May;29(5):602-607. DOI: 10.1097/MEG.0000000000000824
  28. 28. Ij D, Marek SJ, Sridhar S, Wilkins T, Chamberlain SM. Unintentional weight loss as the sole indication for colonoscopy is rarely associated with colorectal cancer. Journal of American Board of Family Medicine. 2011;24:218-219. DOI: 10.3122/jabfm.2011.02.100166
  29. 29. Gaddey H, Holder K. Unintentional weight loss in older adults. American Family Physician. 2014;89:718-722
  30. 30. Shulik O, Cuchhiara A, Pickett-Blackely O. Diagnostic yield of upper endoscopy and colonoscopy for isolated unintentional weight loss. The American Journal of Gastro-enterology. 2014;109(2):AB1969
  31. 31. Fauchais AL, Puisieux F, Bulckaen H, Salomez-Garnier F, Dewailly P. Unexplained weight loss in the elderly: Role of gastric fibroscopy, study of a cohort of 77 patients with a 13-month follow-up. La Revue de Médecine Interne. 2001;22:11-19
  32. 32. Chumlea WC, Garry PJ, Hunt WC, Rhyne RL. Distribution of serial changes in stature and weight in a healthy elderly population. Human Biology. 1988;60:917-925
  33. 33. Wu JM, Lin MH, Peng LN, Chen LK, Hwang SJ. Evaluating diagnostic strategy of older patients with unexplained unintentional body weight loss: A hospital-based study. Archives of Gerontology and Geriatrics. 2011;53:51-54. DOI: 10.1016/j.archger.2010.10.016
  34. 34. Cornoni-Huntley JC, Harris TB, Everett DF, Albanes D, Micozzi MS, Miles TP, et al. An overview of body weight of older persons, including the impact on mortality. The National Health and Nutrition Examination Survey I—Epidemiologic follow-up study. Journal of Clinical Epidemiology. 1991;44(8):743-753
  35. 35. Losonczy KG, Harris TB, Cornoni-Huntley J, Simonsick EM, Wallace RB, Cook NR, et al. Does weight loss from middle age to old age explain the inverse weight mortality relation in old age? American Journal of Epidemiology. 1995;141(4):312-321

Written By

Naim Abu Freha

Reviewed: February 5th, 2018 Published: November 5th, 2018