Effects of HIV on nutrition

Body changes

A man suffering wasting related to HIV and TB infection

AIDS is well known for causing severe weight loss known as wasting. In Africa, the illness was at first called “slim” because sufferers became like skeletons. Yet body changes are not only seen during AIDS; less dramatic changes often occur in earlier stages of HIV infection.
Whereas starving people tend to lose fat first, the weight lost during HIV infection tends to be in the form of lean tissue, such as muscle. This means there may be changes in the makeup of the body even if the overall weight stays the same.¹
In children, HIV is frequently linked to growth failure. One large European study found thatchildren with HIV were on average around 7 kg (15 lbs) lighter and 7.5 cm (3 inches) shorter than uninfected children at ten years old.²

What causes these changes?

One factor behind HIV-related weight loss is increased energy expenditure. Though no one knows quite why, many studies have found that people with HIV tend to burn around 10% more calories while resting, compared to those who are uninfected. People with advanced infection or AIDS (particularly children) may expend far more energy.³
But faster metabolism is not the only problem. In normal circumstances, a small rise in energy expenditure may be offset by eating slightly more food⁴ or taking less exercise.⁵ There are two other important reasons why people with HIV may lose weight or suffer childhood growth failure.⁶
The first factor is decreased energy intake or, to put it simply, eating less food. Once HIV has weakened the immune system, various infections can take hold, some of which can affect appetite and ability to eat. For example, sores in the mouth or throat may cause pain when swallowing, while diarrhoea or nausea may disturb normal eating patterns. Someone who is ill may be less able to earn money, shop for food or prepare meals. Stress and psychological issues may also contribute.
Secondly, weight loss or growth failure can occur when the body is less able to absorb nutrients – particularly fat – from food, because HIV or another infection (such as cryptosporidium) has damaged the lining of the gut. Diarrhoea is a common symptom of such malabsorption.

Effects of antiretroviral treatment

Current antiretroviral drug treatments control HIV infection and prevent severe wasting, as well as other AIDS-related conditions. Emaciated people tend to regain weight once they begin treatment, and stunted children start to grow faster. Nevertheless, the drugs do not eliminate wasting.
Studies have found that relatively small weight loss (between 5% and 10% over six months) is quite common among people with HIV who are taking treatment and not trying to lose weight.⁷ Although this might not seem like much, losses of this size have been linked to an increased risk of illness or death, as discussed below.
In addition, some antiretroviral drugs have been linked to a problem called lipodystrophy. Whereas HIV-related wasting tends to deplete lean tissue, lipodystrophy involves changes in fat distribution. Prolonged treatment is sometimes associated with losing fat from the face, limbs or buttocks, or gaining fat deep within the abdomen, between the shoulder blades, or on the breasts.
Antiretroviral treatment can also contribute to lipid abnormalities by raising LDL cholesterol, lowering HDL cholesterol, and raising triglyceride levels in the blood. This may result in higher risks of heart disease, stroke and diabetes.
Other side effects of antiretroviral treatment include insulin resistance, which can occasionally lead to diabetes.
For a more detailed discussion of these issues, see our antiretroviral drug side effects page.

Micronutrient deficiencies

Micronutrients are vitamins and minerals that the body needs to maintain good health. Researchers have found that people with HIV are more likely to show signs of micronutrient deficiencies, compared to uninfected people. Specifically they have found low levels of vitamin A, vitamin B12, vitamin C, vitamin D, carotenoids, selenium, zinc and iron in the blood of various populations.
Nevertheless, it must be noted that the evidence is not entirely conclusive. It is possible that HIV might affect the markers used to measure micronutrient levels more than it affects the actual amounts of micronutrients available in the body.⁸ Some studies suggest that antiretroviral treatment improves micronutrient status.⁹

References

1. WHO (April 2005), “Consultation on Nutrition and HIV/AIDS in Africa: Evidence, lessons and recommendations for action”
2. European Collaborative Study (January 2003), “Height, Weight, and Growth in Children Born to Mothers With HIV-1 Infection in Europe”, Pediatrics 111(1)
3. Batterham, M. J. (March 2005), “Investigating heterogeneity in studies of resting energy expenditure in persons with HIV/AIDS: a meta-analysis”, American journal of clinical nutrition 81(3)
4. Crenn, P. et al (September 2004), “Hyperphagia contributes to the normal body composition and protein-energy balance in HIV-infected asymptomatic men”, Journal of Nutrition 134(9)
5. Sheehan L. A. and Macallan D. C. (February 2000), “Determinants of energy intake and energy expenditure in HIV and AIDS”, Nutrition 16(2)
6. Wanke, C. (December 2004), “Pathogenesis and Consequences of HIV-Associated Wasting”, JAIDS 37(5)
7. Tang A. M. et al (September 2005), “Increasing risk of 5% or greater unintentional weight loss in a cohort of HIV-infected patients, 1995 to 2003”, JAIDS 40(1)
8. Tang, A. M. et al (June 2005), “Micronutrients: current issues for HIV care providers”, AIDS 19(9)
9. Drain, P. K. et al (February 2007), “Micronutrients in HIV-positive persons receiving highly active antiretroviral therapy”, American Journal of Clinical Nutrition 85(2)