The 41-year-old singer has grown to realise that people will only find her attractive when she felt happy with herself and insists she noticed a change in attitudes when she began to appreciate her looks.
She said: "I was never really able to look at myself in the mirror until I began to hear God telling me I was beautiful. Suddenly, other people started telling me I was beautiful too..."
Mary - who is married to her former manager Kendu Isaacs - also revealed she loves designers who create clothes for "curvy" women who want to embrace their figures.
She told the new issue of Essence magazine: "When Gucci is on, they are on! And what I love about Michael Kors is that he makes clothes for women with curves and for women who can`t hide everything in a slinky dress but want to look great on the red carpet."
Mary recently admitted she has been having problems in her eight-year marriage but laughed off speculation she and her spouse were planning to divorce.
She said: "My marriage is not on the rocks. But I would be a liar and my fans would hate me if I said to them, oh we`re perfect and everything is great.
"We have situations just like everyone else; it`s real. But we love each other, that`s it."