Adults
The most common symptom of malnutrition is unplanned weight loss. If you lose 10% of your body weight in the course of three months and are not dieting, it could be a sign that you are malnourished.
For example, a healthy weight for a woman who is 5ft 8 inches tall (173cm) would be around 10 stone (63 kilos). So, for a woman of this weight and height, losing a stone without dieting could be a sign of malnutrition.
In adults, a useful method of assessing whether you are malnourished is to measure your body mass index (BMI). This is your weight in kilograms divided by your height in metres squared.
For most adults a healthy BMI is between 18.5 and 24.9. This means that:
- a BMI between 17 and 18.5 could suggest you are mildly malnourished
- a BMI between 16 and 18 could suggest you are moderately malnourished
- a BMI of under 16 could suggest you are severely malnourished
Other symptoms include:
- weakening of the muscles, which then begin to waste away
- feeling tired all the time and lacking energy
- increased vulnerability to infection
- delayed wound healing
- dizziness
- irritability
- your nails become brittle
- your skin becomes dry and flaky
- persistent diarrhoea
- depression
- in women, periods become irregular or stop altogether
Children
Symptoms of malnutrition in children can include:
- failure to grow at the expected rate, both in terms of weight and height
- changes in behaviour such as appearing unusually irritable, sluggish or anxious
- changes in hair and skin colour
- hair loss
- swelling of the stomach and legs (this last symptom usually only occurs if a child is severely malnourished)
Vitamin and mineral deficiency
Even if your BMI is in the healthy range you may still not be getting enough vitamins and minerals.
Physical signs that you may have a vitamin or mineral deficiency include:
- skin problems or rashes
- swelling of your tongue
- poor vision at night or in dim light
- you feel out of breath and tired all the time (due to anaemia)
- you experience a constant ringing or buzzing in your ears (tinnitus)
- paleness inside the mouth or eyelids (due to anaemia)
- pain in the bones or joints
When to see your GP
If your BMI is lower than 18.5 or you experience the symptoms listed above it is recommended that you see your GP.
Your child’s weight and physical development should be regularly assessed by your GP or a health visitor in their first few years of life. As part of the National Child Measurement Programme, children in Reception and Year 6 are weighed and measured during the school year.
If you have any concerns about your child’s development or health, contact your GP.
For more information see the Live Well section on Why your child’s weight matters.
