Quitting marijuana and weight gain

I did quit smoking pot at the age of 18 mainly due to anxiety attacks. At the time I was a healthy weight. That was 10 years ago. Around 12 months after quitting, I gained 40kg and still have not been able to shake the weight even though I eat healthy and exercise. So, each person is different, but maybe your best bet is to see your doctor and discuss a weight management plan and have your thyroid function checked.