Title: Non-Invasive Measurements Of Nutritional Status

Key words: Anthopometric measurements, body mass index (BMI), subjective global assessment (SGA),

Date: Oct 1998

Category: 14. Measurement

Type: Article

Author: Dr van Rhijn


Non-Invasive Measurements Of Nutritional Status


In-depth assessments of an individual’s nutritional status include a detailed medical, social and dietary history as well as laboratory and biochemical tests. However, non-invasive methods are extremely valuable and will often suffice for this purpose.

Non-invasive assessment methods

- Age & Gender

It is difficult to measure skin-fold thickness in infants, and is therefore of little value. The WHO recommends that nutritional status is expressed as:

This is a reproducible and practical technique to assess the risk of malnutrition.

It consists of:

- Loss of subcutaneous fat, muscle wasting; ankle & sacral oedema,


The SGA rating is a composite evaluation of the ability to eat, disease stress, functional impairment and clinical wasting. Although the physical examination is part of the SGA, it is generally invaluable in its own right for numerous clinical signs related to the nutritional status such as:


Non-invasive measurements have the benefit that they can be performed anywhere, without expensive laboratory backup. It only requires good clinical judgement and monitoring over time, which is probably the best available method for assessing nutritional status.