A woman in the United States who lost over 90kg after decades of dieting said shedding the weight has made her miserable.
Author Jen Larson, who weighed more than 135kg before gastric band surgery, told the ABC that becoming thin made her more obsessed with her body image.
"Being thin didn't make me happy," she said.
"I'm still looking in the mirror and I'm still hating what I see."
Weight loss expert Bethany Marshall said many overweight people live with the illusion that slimming down will make their lives better.
"What happens is when they lose that buffer they feel that people are scrutinising them," she said.
In her new book Stranger Here Larson writes that losing the weight made her confront the real reasons she was still unhappy.
The author said she now wants to be strong and healthy rather than aspiring to a certain weight or dress size.
She said she is "pretty happy" since coming to terms with her body image and does not regret having the weight loss surgery.
Author: Martin Zavan, Approving editor: Emily O'Keefe