Don't worry. I highly doubt they will discriminate you based on your weight alone. However you might want to lose a bit of weight. It can be quite ironic in the future if you advise patient who is in a high risk group of developing IHD if you yourself are overweight to begin with. Another incentive or curse for being a doctor. You will be constantly being judge by the public in term of image since the public always view the doctor as someone who should know better when it comes to health.