The 25-year-old, who has size 16 feet and weighs around 20 stone, regularly lifted weights and would ride motorbikes to mask his true feelings.
He had dozens of girls chasing him but shunned their advances, preferring to become friends instead and discuss fashion and "girly" things.
In his early 20s, Walker was unable to continue the "charade" and began wearing women's clothes.
He then sought medical advice and began taking oestrogen to become more feminine and now boasts a curvy woman's body and a 38B bra size. I was one of the popular kids in high school," the Daily mail quoted her as saying.
"I was smart and always had girlfriends and loads of girls chasing me. But it somehow didn't feel right, almost like it was a charade.
"I started to feel really isolated as thought here was something wrong with me and at 18 I started doing research secretly into why I was feeling so different from everyone else.
"Although I hid my feelings well I lived my life always knowing there was something different. By 21 I had hit my rock bottom and I started having emotional problems and turned to drink.
"Then one day it just clicked and I knew what I had to do. I started wearing women's clothes and later turned to female hormones to suppress the testosterone in my body.
"One day it just clicked and I knew what I had to do. I started wearing women's clothes and later turned to female hormones to suppress the testosterone in my body," she added.
Lindsey, of Ohio, grew up as Greg and experienced a "normal boyish" childhood as a keen sportsman and gifted basketball player.
He was offered a basketball scholarship to study economics and marketing at Central Michigan College, but dropped out aged 21.
He became increasingly isolated and changed his name from Greg to Lindsey. She then poured her heart out in a letter to her supportive parents explaining she had always felt and wanted to be a woman.
The acceptance gave her the confidence to start wearing women's clothes and undergo a course of female hormones to become more "womanly".