An elderly loved one seems different. She’s losing weight, skipping meals or putting down her fork after just a few bites. He’s withdrawn and tired, making excuses for the empty refrigerator. He looks thinner than ever.

Experts call the problem adult failure to thrive (AFTT) or anorexia of the elderly. Unlike the eating disorders that affect younger people, anorexia in older adults is rarely driven by body image issues. It's far more likely triggered by age-related physical changes that affect eating and digestion, by health conditions like diabetes and by side effects of medication they're taking. It could also result from constipation, dental problems or even a dry mouth.

But sometimes, the problem has psychological roots. Older women and men may stop eating, or cut back drastically, in response to loss, such as the loss of their spouse, or a major transition, such as going from living independently to living in a nursing home.

In these cases, refusing to eat may be an older person's way to draw attention to her plight or gain a sense of control over a life that's increasingly uncertain. Food refusal "may be understood as a form of protest ... particularly when the individuals feel impotent and at the mercy of those around them," according to researchers at St. George's Hospital Medical School in London.

Whatever the cause, unexplained weight loss should be taken seriously. Weight is not a cosmetic issue for the elderly: If their weight drops too low, the heart cannot function properly. For the estimated 35 to 50 percent of adults in their 70s and 80s who have anorexia, the condition can lead to muscle loss and nutritional deficiencies that can weaken bones, sap strength, boost the risk for infections and anemia and interfere with recovery from illnesses or surgery.

In several studies of older adults living independently and in nursing homes, an unexplained weight loss of 5 to10 percent of body weight also increased risk of premature death significantly, according to a review in the journal American Family Physician.

Identifying the cause 

Finding the cause and a solution matters. With care, attention and medical advice, a frail loved one can begin putting on weight. These steps should help you get to the bottom of your loved one's weight loss.

Look for these signs. According to the National Institutes on Aging, signs of AFTT include unexplained weight loss, decreased appetite, inactivity, dehydration, depression, poor immunity and low cholesterol. You may notice some, but not all, of those signs. There may be little or no food in the person’s kitchen cabinets and refrigerator or un-used meals from a meal delivery service. Your loved one may say she's not hungry and refuse to eat if you try to feed her. She may experience chronic dizziness.

Related: How To Help Your Aging Parent Avoid Falls

Make a doctor’s appointment. It’s important to work on helping your loved one eat more, but finding and fixing medical causes is also crucial, according to nutrition experts from the University of Illinois, Urbana. Be sure to tell the doctor what you’ve noticed. Doctors may overlook some everyday problems that make eating difficult. These include mouth infections, stomach or bowel discomfort, loss of teeth, a painful mouth due to cavities or gum disease, poorly fitting dentures, loss of taste or smell, swallowing problems, dry mouth and drinking too much alcohol. Mobility problems can make shopping and preparing food too difficult. If psychological issues are part of the problem, your doctor should be able to recommend another expert, such as a therapist, who can help.

Bring a complete medication list. Medications can interfere with appetite and digestion or cause nausea, vomiting and trouble swallowing. Beta blockers and high-dose diuretics for high blood pressure may cause depression and dehydration. Anti-anxiety drugs including benzodiazepines may blunt the appetite. So can painkillers, antidepressants and anti-seizure medications, according to Temple University experts. The doctor may be able to change, stop or reduce the dose of a drug that causes these problems.

Expect the doctor to do a thorough health check. Depression may cause AFTT, and the doctor should screen for it. But chronic health conditions can also make eating difficult and may need attention. Diabetes can damage digestive-system nerves and slow stomach emptying. Dementia can make people feel indifferent about eating, and the progressive brain damage it causes may mean your loved ones needs to be fed by a caregiver. A stroke or advanced Alzheimer's can lead to swallowing problems. Chronic obstructive pulmonary disease (COPD) can make breathing difficult while eating. And chronic constipation can make your loved one feel full after just a few bites at a meal.

Look more deeply at emotions. An older person may refuse to eat in order to exert some control over his life, especially if he's lost his independence. Or he may have lost his will to live if his spouse and friends are gone. Talk with your loved ones, caregivers and others about what you can do to make things better.

Related: Caregivers, Protect Your Own Health, Too

A few solutions to try

Offer a meal supplement as a snack. If your doctor recommends it, try serving a bottled liquid meal supplement between meals as a snack. Use the type suggested by your doctor. These can provide calories, protein for strong muscles, carbohydrates for energy and vitamins and minerals that your loved one may be missing. One easy way older adults can remember to drink the supplement: Have it while taking medications.

Moisten a dry mouth. A dry mouth, which may be a medication side effect, can make swallowing difficult. Water can help, the NIA suggests. If your loved one has swallowing problems so severe that she chokes on thin liquids, use liquid thickeners (your doctor can tell you more about those and about special cups developed especially for this problem).

Make meals tasty. Loss of smell and taste can make food unappetizing. Enhance flavors with spices, lemon juice and vinegar rather than salt. Try new fruits and vegetables, too.

Related: How Much Salt Is Too Much

Get help for physical problems. If your loved one is having trouble walking, standing or preparing food due to weakness, pain or other muscle and joint problems, tell your doctor. Occupational or physical therapy may help. So can special utensils that make opening cans and jars and preparing and eating food easier.

Eat with your loved one. Join your loved one for meals whenever you can, and urge other relatives to bring food over and eat with him as well. Encourage him to eat with others at home, at his senior center or in the dining room of his retirement community or care center. Studies show that people eat more when they eat with others.

Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.