Obesity: Malnutrition

(asked on 4th September 2023) - View Source

Question to the Department of Health and Social Care:

To ask His Majesty's Government, further to the Written Answer by Lord Markham on 17 February (HL5559), whether individuals who do not have (1) a BMI of less than 18.5 kilograms/m2, (2) unintentional weight loss greater than 10 per cent within the last three to six months, or (3) a BMI of less than 20 kilograms/m2 and unintentional weight loss greater than five per cent within the last three to six months, are therefore not defined as malnourished or undernourished; and whether there are any other scientific measurements or criteria that would justify obese individuals not being defined as malnourished or undernourished.


Answered by
Lord Markham Portrait
Lord Markham
Parliamentary Under-Secretary (Department of Health and Social Care)
This question was answered on 12th September 2023

There is no agreed scientific nor universal definition of overnutrition, however the National Health Service refers to overnutrition as getting more nutrients than needed. Excess intake of macronutrients will mean an excess intake of energy, leading to weight gain and obesity. Excess intake of individual micronutrients may be associated with specific adverse health outcomes depending on the vitamin or mineral. Population prevalence of obesity is monitored by the Health Survey for England and data on population average energy and nutrient intakes are collected by the National Diet and Nutrition Survey. However, at an individual level, healthcare professionals may assess and monitor a patient’s weight and/or nutritional status depending on clinical need.

Although there is no formal assessment of malnutrition at a population-level, NHS Digital collects data on finished hospital admission episodes of malnutrition in England, based on International Classification of Disease (ICD-10) codes. The cause of malnutrition is not presented in the Hospital Episode Statistics.

The criteria referred to are from the National Institute for Health and Care Excellence (NICE) clinical guidelines CG32 ‘Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition’ and are recommended as indications for when nutrition support should be considered. This NICE guideline also states that nutrition support should be considered in people at risk of malnutrition, defined as those who have eaten little or nothing for more than 5 days and/or are likely to eat little or nothing for 5 days or longer; a poor absorptive capacity and/or high nutrient losses; and/or increased nutritional needs from causes such as catabolism. Healthcare professionals might use other screening or assessment tools, or their own clinical judgement regarding additional signs and symptoms, to assess whether someone is at risk of malnutrition.

In the NICE guideline CG32, the term malnutrition is not used to cover excess nutrient provision (overnutrition). However, someone can be a healthy weight or have a body mass index in the overweight or obese categories but be identified through the NICE definition as potentially requiring nutrition support. Hospital Episode Statistics (HES) are also reported for scurvy and rickets, conditions which result from nutrient deficiencies, but these are reported separately to the HES for malnutrition.

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