Investigate unexplained weight loss

Dear Dr. Roach: I am a 72-year-old man in good health. I have lost about 12 pounds in the past year, with no explanation. I’m 5 feet, 9 1/2 inches tall, and my morning weight has dropped from 166-168 pounds to 154-156 pounds. It is still slowly falling.

I eat well, and I’ve exercised an hour every other day for 36 years. I’ve had on-and-off atrial fibrillation for 14 years, with two ablations, but since I began flecainide two years ago, no more episodes.

My doctor did bloodwork and ordered a full CT scan, but found nothing. Since the pandemic began, I’ve been walking 3 miles every other day. The doctor thinks I may be burning more calories than I’m eating, but I doubt it. Would you have any ideas? I was a skinny child so maybe I’m just returning to the high basal metabolism of my youth.

D.S.

Answer: Unexplained weight loss should be taken seriously, especially in an older person.

Sometimes, the body cannot absorb calories properly. Celiac disease and inflammatory bowel disease are the most common, but there are others. The body may lose calories; diabetes causes sugar to come out through the urine. Some infections can cause profound weight loss.

Your metabolism might indeed be high, but that is not a normal condition of aging. Overactive thyroid disease is a condition your doctor has probably already looked for.

Medications are an uncommon cause of weight loss. Flecainide has been reported to cause weight loss in 1% to 3% of users. Some supplements can cause weight loss, too.

Cancer leaps to the mind for many when they hear about weight loss. Colon cancer and prostate cancer should be considered in any 72-year-old man, but especially with weight loss. The CT scan, if it included chest, abdomen and pelvis, should have found lung, kidney or pancreatic cancers, which all are frequently associated with weight loss.

Since your weight loss continues, it’s time for a more thorough re-evaluation. Your youthful basal metabolism probably hasn’t just returned.