I'm so annoyed that i have to try hard to stay fit while some other girls have it so easy?

okay so i'm trying to get a little more toned, im not fat but i'm still a little insecure and i've struggled with insecurity for quite some time, I eat healthy and workout and try hard to get into great shape while these other girls eat like crap literlly eat junkfood everyday don't do much exersise and still look good. i've been down lately so any tips on how i can jsut focus and deal with myself rather than envying these other girls??