5.14 Wasting and weight loss
Severe and unexplained weight loss is a serious symptom of advanced HIV infection. Wasting – also called cachexia – is now rare becasue of the effectiveness of HIV treatment (ART).
Severe weight loss is defined as an unexplained loss of more than 10% over 12 months. It is usually caused by difficulties absorbing food (due to gut infections like giardia, microsporidia and cryptosporidia).
Severe weight loss or wasting is life threatening. It usually reverses after starting ART.
If someone with diarrhoea has weight loss, the cause of the diarrhoea needs to be found. As well as treating the cause, you need to look at diet changes to reduce diarrhoea and improve nutrition. The same is true for nausea and vomiting. Anti-nausea and anti-sickness medication should be prescribed.
Often the best long term response is ARV treatment. But even people using ARV treatment can have difficulty regaining and maintaining higher weight.
Type of illness
Weight loss is a symptom of most of the other OIs discussed in this manual. It can also be a side effect of any illness or treatment that reduces your appetite.
Weight loss or wasting are also caused by HIV itself. This is because the energy that you generate from food and drink is being used by the virus to over-activate your immune system.
The amount of energy from diet that your body needs to function even when just sitting or lying down is higher in HIV-positive people. It becomes higher still as HIV disease progresses. Other infections and illnesses also increase the amount of energy the body needs in order to fight infection.
- Weight loss is a general reduction in weight.
- HIV-related wasting refers to muscle wasting and loss of lean body mass.
Food is basically a source of energy. If you eat less calories each day than your body needs to do the things it needs to, then the extra energy is taken from stores of body fat. If body fat levels are already low, then this extra energy will be taken from protein that is used to build and maintain muscle.
Diagnosis of weight loss is easy and straight-forward because it only requires a pair of scales.
- Weight loss of 10% from normal body weight that can not be explained by other factors (ie change of diet, increased exercise, other infections or medications) becomes an AIDS-defining illness.
- Unexplained weight loss of 5% of body weight over six months is predictive of 10% weight loss in the near future, and should be taken seriously.
When fat loss and wasting occur in the same person, diagnosis and treatment is more complicated. Loss of subcutaneous fat (lipoatrophy, or losing fat under the skin) can be a side effect of ARV drugs and is different to HIV wasting.
In very simple terms, regaining weight should just be a matter of increasing the amount of calories that you get in your daily diet. This may be more difficult if you have gut infections or chronic diarrhoea that reduces your ability to absorb nutrients from food properly.
Achieving this can be hard though. Depending on the cause of weight loss, you may need to try different approaches.
- Special diet advice is essential. Eating more high calorie foods – like fats – may NOT be a good idea. For example, increasing high calorie fatty foods in someone with diarrhoea, will increase the diarrhoea and reduce the likelihood that any nutrition will be absorbed by the body.
- Some liquid nutritional supplements have been developed to help people regain weight.
- If the cause of diarrhoea, nausea and vomiting are other OIs, then ARV treatment should help these symptoms improve. Also, people starting ARV treatment generally put on weight as they find they have a stronger appetite and more energy.
- If thrush in the mouth or oesophagus (part of the gut between the throat and the stomach), or mouth ulcers had made eating difficult or painful, then ARVs will similarly help resolve those problems.
- Steroid use (with exercise), testosterone replacement (for both men and women) and appetite stimulants like Dronabinol (medicinal marijuana) are often used to help regain weight.
If you are HIV positive the best way to avoid the risk of wasting it to use effective ART.
It is easier to lose weight than put weight back on. Early interventions are easier and more successful.
Last updated: 1 January 2016.