Various Nutritional Disorders in the Elderly and Their Management

Definition. As per WHO, malnutrition means deficiencies, excesses or imbalances in a person’s energy and nutrient intake. It therefore includes both undernutrition and obesity.

Spectrum of nutritional disorders in old age. (a) Protein-energy undernutrition, (b) Anorexia of ageing, (c) Cachexia, (d) Sarcopenia and sarcopenic obesity, (e) Micronutrient deficiencies, (f) Dehydration and electrolyte disorders, (g) Obesity.

Epidemiology. Using MNA, overall prevalence is 22.8% — highest in rehabilitation units (50.5%), then hospital (38.7%), lowest in community (5.8%). European meta-analysis: community 6%, hospital 22%, nursing home 17.5%, long-term care 28.7%. Involuntary weight loss occurs in 5–15% of community elders and 27% of frail elders.

Anorexia of ageing. A physiological, age-related fall in appetite and energy intake that exceeds the fall in energy expenditure, causing weight loss. Prevalence rises from 3.3% in the community to 33% in nursing homes. Loss of appetite is the key predictor of malnutrition.

Pathophysiology. Four mechanisms — loss of homeostatic regulation (elders do not compensate after underfeeding), the ageing gut (myenteric plexus cell loss, early satiation, reduced sensitivity to distension), declining taste and smell, and hormonal changes — chiefly raised CCK levels with increased sensitivity to CCK; leptin, NPY and CART changes are also implicated.

Pathological causes (all at least partly treatable). Depression (2–10% community, higher in institutions), dementia (~2-fold risk of anorexia; up to 50% of institutionalised dementia patients have PEM), COPD, CHF (anorexia in >40% of end-stage CHF), CKD, cancer, drugs and polypharmacy, poor dentition and dysphagia, immobility, tremor, poor vision, poverty and isolation. Use the “MEALS ON WHEELS” mnemonic to search for treatable causes.

Classification by inflammatory grade. Starvation (pure protein-energy deficit, CRP <3 mg/L) → inflammageing (low–medium) → cachexia (medium-grade inflammation, disease-related) → hypercatabolic malnutrition (sepsis, trauma; high-grade inflammation).

GLIM diagnostic criteria — need one phenotypic + one etiologic criterion. Phenotypic: non-volitional weight loss >5% in 6 months or >10% beyond 6 months, low BMI, reduced muscle mass. Etiologic: reduced food intake or assimilation, inflammation / disease burden.

Clinically significant weight loss. 5% in 1 month, 7.5% in 3 months, or 10% in 6 months. BMI <22 kg/m² predicts higher one-year mortality and poorer function; ideal BMI ranges are higher in older than younger adults. Weight change is preferred to BMI because kyphosis makes height unreliable.

Screening tools. MNA and MNA-SF are standard: 12–14 normal, 8–11 at risk, 0–7 malnourished; uses BMI or calf circumference (<31 cm). MNA is 96% sensitive, 60% specific for weight loss and is a powerful prognostic factor, especially in cancer. Alternatives: SGA, SNAQ.

Laboratory assessment. Serum albumin is practical but confounded by liver disease, proteinuria and protein-losing enteropathy; prealbumin and retinol-binding protein are more sensitive. Total lymphocyte count is a useful marker. Anaemia is one of the earliest manifestations of protein-calorie malnutrition.

Micronutrients of public health concern in elders. Vitamin D, calcium, B12, folate, B2, B6, vitamin C, vitamin E, vitamin A, choline, zinc, magnesium, potassium, selenium. An energy intake <1500 kcal/day generally guarantees micronutrient inadequacy — hence the emphasis on nutrient-dense foods.

Vitamin B12 deficiency. 10–30% of elders malabsorb food-bound B12 (atrophic gastritis); pernicious anaemia in 1–2%. Features: macrocytic anaemia, fatigue, anorexia, weight loss, paraesthesiae, ataxia, depression, dementia, glossitis. Diagnosis: low B12 with raised MMA and homocysteine; oral high-dose is as effective as intramuscular.

Folate deficiency. Stores are small, so deficiency develops in weeks to months. Homocysteine raised, MMA Nutrition in the Elderly — MD Geriatric Medicine Revision Page 3 of 25 normal (distinguishes it from B12 deficiency). Causes: alcohol, malabsorption, methotrexate, sulfasalazine, trimethoprim, phenytoin. Treat with folic acid 1 mg/day.

Zinc and iron. Zinc deficiency causes anorexia through impaired taste and smell, impaired immunity, poor collagen synthesis and wound healing, diarrhoea and confusion; common in diabetics. Iron deficiency is less common than in the young — always exclude chronic GI blood loss and distinguish from anaemia of chronic disease (ferritin, CRP).

Calcium and vitamin D. Recommended intake after age 50: calcium 1000–1200 mg/day, vitamin D 800 IU/day; upper limits 2000 mg and 4000 IU. Treat 25(OH)D <10–12 ng/mL; adequacy usually taken as ≥20 ng/mL. Supplementation reduces bone loss, fractures and falls and improves sarcopenia.

Dehydration. Very common and potentially lethal — hospital mortality up to 50%. Due to reduced thirst, a fall in total body water from 60% to 50% after age 75, and reduced aquaporin-2 responsiveness to ADH. Commonest precipitants: infection, altered consciousness, cognitive impairment, diuretics. Acute loss ≥3% body mass or >1 kg/day suggests dehydration. Advise ~1.5 L fluid daily. Correct hypernatraemia by <10 mEq/L/24 h and hyponatraemia by 6–8 mEq/L/24 h to avoid cerebral oedema and osmotic demyelination.

Obesity and sarcopenic obesity. In those ≥65, overweight (BMI 25–29) carries no excess mortality and obesity only a modest increase. Sarcopenic obesity = low lean mass with increased fat mass. Weight loss is indicated only when there is functional impairment or metabolic complication, using a modest deficit of 500–700 kcal/day plus resistance exercise to protect muscle and bone. Bariatric surgery only for highly selected older patients.

Management of undernutrition — five steps. Step 1 — treat reversible causes through comprehensive geriatric assessment (cognition, depression, drugs, dentition, swallowing, constipation, social and financial support). Step 2 — food-first measures: oral and dental care, texture modification, flavour enhancement, feeding assistance, food fortification, meals-on-wheels. Step 3 — oral nutritional supplements (ONS): meta-analysis of 42 trials showed 2.3% weight gain and reduced mortality (RR 0.74) — benefit was significant when ≥400 kcal/day was given for ≥35 days to unwell, malnourished patients aged ≥75 in hospital or nursing homes. No proven improvement in functional status or length of stay. Step 4 — exercise: progressive resistance training 2–3 times/week is the primary intervention for sarcopenia, improving strength, gait speed and chair rise even in the very old. Step 5 — enteral nutrition if oral intake is inadequate; parenteral only if enteral is impossible. PEG feeding in nursing-home residents with severe cognitive impairment did not improve 24-month survival, and aspiration pneumonia occurred at the same rate with or without tube feeding.

Palliative/orexigenic drugs and prognosis. Megestrol acetate is the best studied (increases appetite, weight and quality of life; oedema is the significant adverse effect). Corticosteroids improve appetite without weight gain; cyproheptadine likewise; cannabinoids (dronabinol, nabilone) and thalidomide (anti-TNF) have limited evidence. Unintentional weight loss is an independent predictor of mortality, functional decline, disability and institutionalisation — it is a marker of poor prognosis, not merely a nutritional problem.

GLIM criteria — 5-year update. A 43-member working group reviewed >400 publications (2019–2024) and confirmed strong construct and predictive validity. No revisions were made to the weight loss, low BMI or reduced food intake/assimilation criteria; assessment of low muscle mass should be guided by experience and available technological resources, and clinical judgement may suffice for the inflammation/disease burden criterion. (Jensen GL, et al. Clin Nutr / JPEN. 2025.)

Practical bedside GLIM muscle-mass surrogates validated. Using calf circumference <31 cm in both sexes, or MUAC <23 cm in men and <22 cm in women, gave 84.6% and 83.4% accuracy against SGA, with sensitivity ~89% and ~84%. Directly relevant to Indian practice where DXA/BIA is unavailable. (Shahraki Jazinaki M, et al. Front Nutr. 2024.)

GLIS — first global conceptual definition of sarcopenia. Muscle mass (89.4%), muscle strength (93.1%) and muscle-specific strength (80.8%) were all accepted as components of sarcopenia, whereas impaired physical performance was accepted as an outcome rather than a component. This supersedes the textbook’s EWGSOP-based framing. (Kirk B, et al. Age Ageing. 2024.)

ESPEN practical guideline, geriatrics. Eighty-two evidence-based recommendations: all older persons shall be routinely screened for malnutrition; oral intake supported by nursing interventions, counselling, food modification and ONS; enteral nutrition if oral is insufficient and parenteral if enteral is insufficient or impossible, when prognosis is favourable; dietary restrictions should generally be avoided. Low-intake dehydration should be diagnosed on serum Nutrition in the Elderly — MD Geriatric Medicine Revision Page 4 of 25 osmolality and corrected with hypotonic fluids given orally, subcutaneously or intravenously depending on severity; weight loss should be considered only in obesity with associated health problems, using moderate energy reduction with exercise. (Volkert D, et al. Clin Nutr. 2022;41:958–989.)

ESPEN guideline on nutrition and hydration in dementia — Update 2024. A full guideline update giving evidence-based recommendations for nutritional care in persons with dementia, to prevent and treat malnutrition and low-intake dehydration. (Volkert D, et al. Clin Nutr. 2024.)

ESPEN practical guideline: nutritional support for polymorbid medical inpatients (2024). Reaffirms screening-then-treat. The EFFORT trial showed that reaching ≥75% of estimated nutrition goals, versus lower achievement, significantly lowered the risk of adverse events and mortality. However, the 6-month secondary analysis found that while individualised nutritional support during hospital stay significantly reduced short-term mortality, there was no legacy effect on longer-term outcomes. (ESPEN. Clin Nutr. 2024; Schuetz P, et al. Lancet. 2019; Clin Nutr. 2020.)

Vitamin D — Endocrine Society guideline 2024. Empiric vitamin D supplementation is suggested in the general population aged 75 years and older because of the potential to lower mortality risk, with routine 25(OH)D testing suggested against in this group. For non-pregnant people over 50 in whom vitamin D is indicated, daily administration is suggested rather than intermittent high doses. (Demay MB, et al. J Clin Endocrinol Metab. 2024.)

Vitamin D — USPSTF draft recommendation (Dec 2024). Moderate certainty that vitamin D with or without calcium has no net benefit for primary prevention of fractures, and vitamin D has no net benefit for prevention of falls, in community-dwelling postmenopausal women and men aged 60 and older — a D grade. It does not apply to people taking these for other medical reasons, to those in assisted living or nursing homes, or to those diagnosed with osteoporosis or vitamin D deficiency. (USPSTF Draft Recommendation Statement. 2024.)

Megestrol now discouraged. The 2023 AGS Beers Criteria lists megestrol as avoid (strong recommendation, moderate quality) — minimal effect on weight, with increased risk of thrombotic events and possibly death in older adults. (AGS Beers Criteria Update Expert Panel. J Am Geriatr Soc. 2023;71.)

Indian data — LASI Wave 1. Among those aged 60 and above, 28% of men and 25% of women are underweight, while 25% of men and 37% of women aged 45–59 are overweight or obese; the urban population is less likely to be underweight and more than twice as likely to be overweight, and older adults from low economic and social strata are more likely to be underweight. Using a modified MUST, about 26% were classified as undernourished high-risk, characterised by low BMI, recent hospital admission and food-insecure households. (Khan J, et al. Sci Rep. 2023;13; LASI analysis. BMC Public Health. 2023.)

WHO BMI cut-offs may misclassify Indian elders. CART analysis of LASI data derived age-appropriate cut-offs — the underweight threshold fell from <18.5 to <17.4 for those aged 60–74 and <13.3 for those 75 and above. (Singh A, Chattopadhyay A. Sci Rep. 2024;14.)

ICMR-NIN Dietary Guidelines for Indians 2024. Seventeen guidelines addressing India’s double burden of malnutrition, introducing the “My Plate for the Day” model and integrating RDA 2020 (safe protein requirement 0.83 g/kg/day, EAR 0.66 g/kg/day, with DIAAS replacing PDCAAS for protein quality). The guidelines discourage the use of protein supplements and high-protein concentrates for muscle building, citing bone mineral loss and kidney damage with prolonged intake. (ICMR-NIN. Dietary Guidelines for Indians. 2024.)

GLP-1 receptor agonists and the older adult — a new nutritional concern. GLP-1 RAs effectively induce weight loss, but concomitant muscle mass loss is common, raising concerns about sarcopenia and sarcopenic obesity in older adults. A meta-analysis of eight RCTs found participants regained 9.69 kg over 48–52 weeks after stopping semaglutide or tirzepatide. Short-to-mid-term trials show handgrip strength is statistically preserved despite reductions in lean soft tissue, but longitudinal and retrospective studies in older adults with type 2 diabetes report reduced handgrip strength and accelerated sarcopenia with prolonged semaglutide use. Practical implication: combine with adequate protein and resistance training in elders. (Curr Nutr Rep. 2026; Maturitas. 2025.)