Oprah was at her heaviest weight (237 pounds) in 1992, and she lost that weight by working closely with her personal trainer Bob Greene, who helped her eat healthy and exercise.
Oprah has been in the public eye for close to three decades, and during that time, her weight has gone up and down several times. When Oprah first lost 67 pounds in 1988, she rolled a wagon of fat weighing that amount onto her show's stage. Unfortunately, she has gained that weight back and lost it several times since that iconic episode.
When Oprah describes how she lost weight in the 1990s, she makes it sound simple, and she claims that people just need to work out more and eat less. In particular, she suggests walking at least 10,000 steps per day, a goal that can be tracked with a pedometer, and reducing the starchy foods in one's diet.
Oprah has consulted with medical professionals about her weight, and she has taken medication for thyroid issues. Her doctor once told her that she needed to "embrace hunger" so that she could learn to deal with it, but the star admits to not being prepared for that. Ultimately, Oprah weaned herself off that medication, admitted that she was a bit depressed, and took a few weeks off. During this time, she ate flax seed, rested a lot, and worked out on a treadmill to help with her weight issues.