Minnoch was born in Seattle in 1941. His parents moved the family to Bellingham when he was an infant, and his father worked as a machinist until dying of a heart attack in 1962. His mother, a graduate of Seattle Pacific University, worked as a registered nurse and later as a telephone operator. Minnoch's obesity began in childhood. At twelve, he weighed 294 pounds. By twenty-two, he had reached 392 pounds, and by 1963, the scale read 700. He stood six feet tall. Despite these numbers, Minnoch pursued an ordinary life with visible determination. He drove cabs for seventeen years, married Jean McArdle in 1963, and ran the taxi company alongside her on Bainbridge Island. The couple divorced in 1980, and he married Shirley Ann Griffin in 1982.

In March 1978, Minnoch was admitted to the University of Washington Medical Center in Seattle, suffering from heart and respiratory failure. Transporting him required over a dozen firefighters, rescue personnel, and a specially modified stretcher. At the hospital, two beds were pushed together to support him, and thirteen attendants were needed to roll him over. Doctors diagnosed massive edema on top of his obesity. Placed on a strict diet of 1,200 calories per day, Minnoch remained in the hospital for approximately two years. When he was finally discharged, he weighed 476 pounds, having lost 924 pounds, the largest documented human weight loss at that time. "I've waited 37 years to get this chance at a new life," he told reporters, hoping to reach 210 pounds eventually.

The new life Minnoch hoped for proved elusive. After leaving the hospital, his weight climbed again, reaching 952 pounds before he was readmitted. He died on September 4, 1983, at the age of 41, weighing 798 pounds. His casket, built from plywood and lined with cloth, required two cemetery plots at Mount Pleasant Cemetery in Seattle. Around eleven men were needed to carry it to the burial site. Minnoch's story resists easy lessons. He was not a spectacle but a person who fought his body's appetites and mechanics with the tools available to him, in a time when medicine understood far less about severe obesity than it does today. British obesity specialist David Haslam noted that Minnoch's water retention was likely a consequence of his weight, not its cause, a distinction that matters medically but did nothing to lighten the burden Minnoch carried every day of his life.