Miles Dewey Davis III (May 26, 1926 – September 28, 1991) was an American jazz trumpeter, bandleader, and composer.
Widely considered one of the most influential musicians of the 20th century, Davis was at the forefront of almost every major development in jazz from World War II to the 1990s. He played on various early bebop records and recorded one of the first cool jazz records. He was partially responsible for the development of modal jazz, and jazz fusion arose from his work with other musicians in the late 1960s and early 1970s.
From Rolling Stone magazine, Issue 48 — December 13, 1969 (see cover right)
Jackson and Miles' eldest son, Gregory, joined us for lunch at one of Miles' favorite eating places, Floogie's. (Gregory is also a boxer and won three titles while he was in the Army, a point of considerable paternal pride.)
With all of us crowded into a booth, Miles the Provider emerged. He made sure everybody got something to eat, offered to share his food (he's now a vegetarian as well as a nondrinker and nonsmoker), advised his son on what to eat, and generally held court.
The full interview on rollingstone.com
From 'So What' - biography of Miles Davis by John Szwed:
Two months after his divorce from Frances Taylor in February 1968 . . . became involved with Betty Mabry, a twenty three year old . . . they were married . . . on September 30, 1968.
With Betty as his muse, Miles began training at the gym again, even as the pain in his hip and legs worsened. He stopped smoking, turned to health food, and travelled with his own trainer.
Szwed also refers to Miles 'pacing the stage in leather and suede' - the timing is not clear but it does suggest that his interest in vegetarianism at that time was purely health related. The marriage only lasted about one year and Miles was back on drugs around the time it broke up - though the Rolling Stone article above was published in December 1969. Referring to mid 1970, Szwed continues:
Davis had his house done over again . . . fur rugs on the floor . . . In the living room was an animal skin sofa, a tiger's head . . . [obviously not into animal rights!]
Miles continued his struggle to stay in shape. He stopped drinking, and avoided meat and fish. The battle he had with heroin was now being repeated with other substances and foods that he should avoid, and he was resisting them as part of his daily combat. Sometimes he won, sometimes not, but personal skirmishes like these kept him edgy and volatile for the rest of his life.
In 1971 Miles was back to drinking, using various drugs, and binging on a lot of sugar/dairy junk foods, though seemingly what still might technically be called 'vegetarian'. By 1976 there are references to fried chicken and over the next few years his drug and alcohol dependency had increased as his health worsened. Then in November 1981 he married Cicely Tyson and things began to improve again:
Whne went to London at the end of April  . . . Miles talked to the press about his illnesses and recuperation, . . . he chatted about his new healthy life, often crediting Cicely, . . .
After returning to the United States, Cicely and he spent time in Pawling Health Manor, a [completely vegetarian] spa in upstate New York where he had the time to relax, dry out and eat well. . . . When Cicely and Miles went back to New York City, the limousine was loaded with . . . cases of kiwi and papaya, bushels of corn and apples, sacks of cucumbers, broccoli, and pineapples, a tub of lettuce, and a recipe for making carrot cutlets. When a reporter asked if carrots beat pork chops, Miles, worried about the weight he was adding on his waist, said, "No, but it beats another ten pounds."
He later split from Cicely and there was another reference to chicken.... for his remaining years Miles struggled with diabetes, aggravated by his binging on sweets. He generally seems to have kept off the drugs, alcohol and tobacco but the changes were all too late to reverse all the damage done earlier.