The caption is directed to online "trolls" who she says write "unkind things." She writes, "This is how I look. I feel happy" before adding that she thinks she looks "strong and healthy."
Slamming body critics is nothing new for Schumer. She told Glamour magazine it was "not cool" in another Instagram post last month for mentioning her in an issue focused on plus size fashion.
She wrote that there's nothing wrong with being plus-size, but disputed having a plus-size body, suggesting that labeling her body type that way could have a negative influence on young girls.
Reality TV star Kim Kardashian finds it difficult knowing some runway designs won't suit her body shape but says she has learned to embrace her curves.
