The most abundant nutrient present in the body is?

Appeared in: PGIMS Rohtak NO - 2017

Explanation

Water is the most abundant constituent in the human body, making up approximately 60% to 70% of the total body weight in an average adult.
This high percentage is due to water's critical role in all physiological processes, including acting as a solvent, a transport medium, a temperature regulator, and a lubricant.
The percentage of body water varies based on age, gender, and body composition; for example, infants have the highest percentage, and it decreases with age.
Lean tissue contains significantly more water than adipose (fat) tissue, so individuals with more muscle mass have a higher percentage of body water.

Option A: Carbohydrates constitute less than 1% of total body weight. They are primarily used for immediate energy and stored in small amounts as glycogen.
Option B: Protein is the second most abundant substance after water, making up about 15-20% of body weight. It is the main structural component of cells and tissues.
Option C: Lipids (fats) are highly variable but typically account for 10-30% of body weight. While they are a significant component, they are less abundant than water.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Nutrient composition of the human body as background academic context rather than a clinical decision trigger.
Understanding that water is the most abundant component is fundamental to nursing practice, especially in fluid and electrolyte management. Dehydration and overhydration can have severe consequences.
A nurse's assessment of hydration status is a critical skill. Signs of dehydration include poor skin turgor, dry mucous membranes, decreased urine output, and tachycardia.
Daily weighing of a patient is the most sensitive indicator of fluid balance changes. A 1 kg (2.2 lb) change in weight overnight is equivalent to a 1-liter fluid gain or loss.

How to Approach the Question

First, identify the key term in the question: 'most abundant'. This directs you to find the substance present in the largest quantity.
Next, analyze the options provided: Carbohydrate, Protein, Lipid, and Water. These are the major classes of nutrients.
Recall the basic composition of the human body from your study of anatomy and physiology.
Compare the relative percentages of each component. You should remember that the human body is primarily composed of water.
Water makes up about 60% of an adult's body weight. Proteins are next (~15-20%), followed by lipids (variable, ~10-30%), and finally carbohydrates (<1%).
Based on this comparison, conclude that water is, by a large margin, the most abundant nutrient.

Concept Tested & Keywords

QAdgwRf6BRp0_Ri5TZ99-U

E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 180-182

E6 Nutrition Monika Sharma 3e p. 54-56

Practise the full PGIMS Rohtak NO - 2017

Attempt every question from this paper in a timed mock, then review the full solution for each one.