science

Wasting

Wasting is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Wasting rather than just read about it. In short: In medicine, wasting, also known as wasting syndrome, refers to the process by which a debilitating disease causes muscle and fat tissue to "waste" away. Wasting is sometimes referred to as "acute malnutrition" because it is believed that episodes of wasting have a short duration, in contrast to stunting, which is regarded as chronic malnutrition.

Key takeaways

Wasting belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Wasting to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Wasting from memory before moving on to harder problems.

Reference excerpt

In medicine, wasting, also known as wasting syndrome, refers to the process by which a debilitating disease causes muscle and fat tissue to "waste" away. Wasting is sometimes referred to as "acute malnutrition" because it is believed that episodes of wasting have a short duration, in contrast to stunting, which is regarded as chronic malnutrition. An estimated 45 million children under 5 years of age (or 6.7%) were wasted in 2021. Wasting prevalence declined from 7.5% in 2012 to 6.8% in 2022, with 6.2% of children under five years old projected to be wasted in 2030, more than double the 3% Sustainable Development Goals target. Prevalence is highest in Southern Asia, followed by Oceania (excluding Australia and New Zealand) and South-eastern Asia.

Causes Wasting can be caused by an extremely low energy intake (e.g., caused by famine), nutrient losses due to infection, or a combination of low intake and high loss. Infections and conditions associated with wasting include tuberculosis, chronic diarrhea, AIDS, and superior mesenteric artery syndrome. The mechanism may involve cachectin – also called tumor necrosis factor, a macrophage-secreted cytokine. Caretakers and health providers can sometimes contribute to wasting if the patient is placed on an improper diet. Voluntary weight loss and eating disorders are excluded as causes of wasting.

Diagnosis

Classification Children: Weight-for-height (WFH). In infants under 24 months, recumbent (supine) length is used. WFH as % of median reference value is calculated this way:

W F H = weight of a given child median weight for a given child of that height × 100 {\displaystyle \mathrm {WFH} ={\frac {\mbox{weight of a given child}}{\mbox{median weight for a given child of that height}}}\times 100}

Cutoff points may vary, but <80% (close to −2 Z-score) is often used.

Adults: Body Mass Index (BMI) is the quotient between weight and height squared (kg/m2). An individual with a BMI < 18.5 is regarded as a case of wasting. Percent of body weight lost (At Tufts, an unintentional loss of 6% or more in 6 months is regarded as wasting)

Treatment Antiretrovirals and anabolic steroids have been used to treat HIV wasting syndrome. Additionally, an increase in protein-rich foods such as peanut butter and legumes (dried beans and peas) can assist in controlling the loss of muscle mass.

See also Anorexia Atrophy Cachexia Superior mesenteric artery syndrome Weight loss

References

External links

Chronic Wasting Disease and Potential Transmission to Humans, Center for Disease Control and Prevention Unintentional Weight Loss/Wasting, Tufts University Nutrition/Infection Unit

Illustrations

Worked examples

Example 1 — a first encounter with Wasting

Start with the simplest possible case. Write down what Wasting claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Wasting before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Wasting ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Wasting

In research: Wasting appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Wasting in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Wasting is common in secondary-school and first-year university syllabi. It links to neighbouring topics Symptoms and signs, so understanding it makes those chapters shorter.
In everyday life: Look for Wasting outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Wasting in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Wasting means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Wasting out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Wasting in simple terms?

Why does Wasting matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Wasting?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Wasting.