While many more people suffer from excess appetite, and would rather decrease it so they can lose weight, some people find that they have insufficient desire to eat food and thereby lose weight even though they don’t want to. Mild weight loss can occur in relatively healthy people with stomach problems such as dyspepsia or gastric atonia (sluggish action of the stomach). More severe loss of weight can occur among people who are receiving cancer chemotherapy or have serious diseases such as HIV, emphysema (COPD), Crohn’s disease, or congestive heart failure. In extreme cases, inadequate caloric and fat intake leads to a form of starvation (cachexia) that can hamper recovery and increase the risk of death.

Conventional treatment of undesired weight loss primarily involves concentrated protein-calorie supplements, often taken in liquid form. However, among people who have cancer, simply increasing nutritional intake may not help. Cancer can cause a condition called tumor-induced weight loss (TIWL), in which symptoms of starvation occur despite apparently adequate nutrition. The cause is thought to be a particular form of inflammation caused by the cancer. For this reason, nonsteroidal anti-inflammatory drugs have been tried for the treatment of TIWL, with some positive results.1 Progesterone-related drugs may be helpful for TIWL as well, for reasons that are not clear.

Note: This article does not cover psychological eating disorders, such as bulimia or anorexia.

Principal Proposed Natural Treatments

Fish oil contains omega-3 fatty acids, “good fats” that have many potential health-promoting properties. As noted above, cancer-induced weight loss involves inflammation and responds to treatment with anti-inflammatory drugs. Fish oil also has anti-inflammatory effects. According to some, though not all, studies, fish oil supplements can help people with cancer gain weight.2-4

A typical dosage of fish oil used for cancer-induced weight loss is about 12 g daily. For more information, see the full Fish Oil article.

Other Proposed Natural Treatments

Fats are a concentrated form of energy and, for that reason, people with undesired weight loss are often encouraged to increase fat intake. People with cancer have an additional reason to consume more fat: cancer interferes with the normal process of fat storage, making it less efficient. Certain special fats may be particularly helpful for correcting this “fat deficiency,” including conjugated linoleic acid (CLA)5 and medium-chain triglycerides (MCTs),6 along with fish oil as discussed above.

People with HIV/AIDS may have trouble absorbing fats. Two small double-blind studies have found that MCTs are more easily absorbed than ordinary fats in people with this condition.21,22

However, there is no direct evidence as yet that MCTs actually help people with HIV infection gain weight. Note: In both of the studies noted here, participants consumed nothing but a special nutritional formula containing MCTs. Taking MCTs in this way requires medical supervision to determine the dose.

People with excessive weight loss due to serious illness may also need extra protein. Amino acids are the basic building blocks of proteins, and may be easier to digest than whole proteins. Certain amino acid supplements have shown particular usefulness in treating cancer cachexia. One such is branched-chain amino acids (BCAAs), a collection of the amino acids leucine, isoleucine, and valine.7 A double-blind study tested BCAAs on 28 people with cancer who had lost their appetites because of either the disease itself or its treatment.8 Appetite improved in 55% of those taking BCAAs (4.8 g daily) compared to only 16% of those who took placebo.

Promising results for both cancer-induced and HIV-induced weight loss have also been seen with the amino acids arginine, glutamine, and ornithine alpha-ketoglutarate (OKG).9-20

Other treatments found useful for cancer- or HIV-induced weight loss include the antioxidants lipoic acid and N-acetyl cysteine (NAC),1 a cocktail containing the sports supplement beta-hydroxy-beta-methylbutyrate (HMB) combined with the amino acids arginine and glutamine,18,20 and the hormone melatonin.7

Traditional remedies for mild, occasional loss of appetite involve the use of bitter-tasting herbs, such as gentian (sold as “bitters” in liquor stores), devil’s claw, goldenseal, hops, and horehound.

In one study, use of the supplement creatine failed to help maintain muscle mass in people undergoing chemotherapy for colon cancer.23

Herbs and Supplements to Use Only With Caution

Various herbs and supplements may interact adversely with drugs used to treat the underlying condition causing weight loss. For more information on this potential risk, see the individual drug article in the Drug Interactions section of this database.