New Delhi, Sept. 6 -- On most mornings, 64-year-old Suman Nair sits by her kitchen window in Kochi, peeling an apple for breakfast. The apple is crisp and sweet, but it's the only fruit she eats raw. Everything else in her diet (a dry roti without ghee, watery dal, and plain boiled vegetables) is part of a "heart-friendly" plan she adopted a decade ago after her husband's bypass surgery.

"I cut out all fats. Even coconut, and we are Malayalis!" she says with a wry laugh. "I thought it was the right thing to do."

By the time her daughter, who works in Mumbai, brought her to my clinic last year, Suman's knees hurt constantly. She would get tired easily, and her blood reports showed steadily falling muscle mass. Nothing was "wrong" accordi...