While everyone is saying the snake is underweight, that may not be the case. It could be a slow grower, just pooped, etc.

Can you post a picture of your snake? Your snake should have a full look to it and not a "triangular" look. For example, here's a picture of my normal the day I got her. She was 6 months old and only 44g (Yes, 44g). Now she weights 550g and looks amazing. there's a before and after to show you the difference.

This picture is small, but even at such a small picture size, you can see her spine and she clearly has a triangular shape. This was taken in early July:



This next picture was taken right before Christmas when she was about 400g. You can see her spine and see how she's filled out:



Like I said above, snakes can grow at different rates and whether or not they've eaten or pooped can play a huge role in how much they actually weigh. So, post up a picture of your snake and we can tell you if it's a healthy weight or it could be beefed up a bit. Also, what are you feeding your snake and how often? Too small of a feeder size and feedings pretty spread out can cause slow growth.