Being jealous of someone else’s success is a waste of your time. The fact that they are successful does not mean that you can’t be successful too. They are successful at being themselves. You are different. Be yourself. Being jealous of someone else is childish. They haven’t taken away your toy.
I know people who are jealous of other people for losing weight. The fact that another person has made the time to exercise and worked up the discipline to eat well does not take away from your ability to do the same. The more time you spend getting mad at another person’s success, the less time you are spending on creating your own.
Perhaps you can learn something from the other person’s story that might encourage you. Perhaps you might learn a new way of thinking that will make it easier for you to get healthy. Their success can be the springboard for your own.