Merck Manual

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Causes of Undernutrition

Causes of Undernutrition

Cause

Examples

Lack of access to food

Famine

Inability to obtain food (for example, due to lack of transportation or physical impairment)

Poverty

Conditions that restrict the amount or type of food eaten

Fad diets

Some vegan or vegetarian diets

Voluntary restriction of calories (as for a strict reducing diet or a fast)

Conditions that interfere with the intake, metabolism, or absorption of nutrients

Drug abuse

Impaired mental function, such as dementia Dementia

Sometimes surgery to promote weight loss ( bariatric surgery Bariatric Surgery )

Drugs that interfere with the intake, metabolism, or absorption of nutrients

Some drugs used to treat anxiety, high blood pressure, heart failure, an underactive thyroid gland ( hypothyroidism Hypothyroidism Hypothyroidism ), asthma, or cancer

Conditions that greatly increase the need for calories

Demanding exercise, such as rehabilitation or training for athletic competition

Injury, such as burns

High fever

Infections that are widespread or severe

Growth and development in infants, children, and adolescents

An overactive thyroid gland ( hyperthyroidism Hyperthyroidism Hyperthyroidism )

Pregnancy and breastfeeding

Surgery