i have had 2 ba’s and have lost about 4 stone in total, 2 stone after first ba and another 2 stone since the last one -so in the space of 3 years and it hasn’t affected mine at all.I was a natural c cup so i did have some breast tissue to start with but mine look exatly the same.It depends where you usually lose weight from first, everyones different i suppose.I don’t think that 7lbs would have any effect. x