A woman was told she looked like a whale after documenting her incredible postpartum transformation on Instagram

The mother-of-three was told she looked too skinny after losing her baby weight

Amy has worked hard to get back in shape so she can be healthy for her children (Instagram)

Reverting back to pre-baby weight is never easy - and for one mum-of-three, cruel comments online made it even harder.

Amy, 33, a fitness blogger based in Germany, recently posted her postpartum body on Instagram, where she shares her health and workout routines to her 14,000 followers on the Instagram account @fitness.fireball.

In the photo, Amy shows off what her pregnant belly looked like prior to giving birth to her daughter Olivia in April 2017, and what her body looked like one month, two months, and three months postpartum.

She also included her measurements and her weight to give her followers an accurate update of where she is in each photo.

Posing in the same bathing-suit in each photo, her transformation - the result of eating healthy and exercise, is remarkable.

But rather than support and encouragement for her incredible progress, the fit mum instead received hateful comments that criticised her appearance.

“You look like a whale. Were you really pregnant? You are too skinny now,” are just some of the body negative comments left on Amy’s photos - which she shared in an Instagram caption.

In the first photo, where she is heavily pregnant with her daughter, she weighed 72 kilograms (158 pounds) and three months postpartum weighed 52.5 kilograms (116 pounds).

However, Amy hasn’t taken the criticism to heart - and has instead shared with her followers how hurtful these comments can be to a new mum.

She wrote: “Obviously, now that my hormones and sleep cycle are almost back to normal I don’t take any of those comments above serious.. ⠀⠀

“But when my sleep was non existent and my emotions was all over the places those comments definitely hurt.”

Amy said the comments were especially hurtful because many of them came from other women, who are criticising instead of supporting other women.

The new mum also shared why and how she worked on her body - which all has to do with staying healthy for her children.

“I took care of my body, so I could move again without pain, so I could get off my medications, so I could carry my older kids without feeling like my body was falling apart.

“The physical results that came from eating healthy and working out was just a bonus,” Amy wrote.

The new mum ended her post with words of support for other new mums - whether they are trying to get back in shape or not.

She wrote: “Whatever makes your motherhood transition easy and Don’t let ANYONE make you feel ashamed for taking actions towards your happiness and peace.”

Amy’s honest post has prompted an outpouring of support from her followers - but despite the words of encouragement, the new mum acknowledged how important it is to find sources of happiness in life that aren’t connected to social media.