First of all, congratulations on changing your lifestyle - the diet that you are currently following sounds much better and healthier than your previous diet. That being said, a large amount of weight loss
is a stress to your body as it breaks down all that fat, so I recommend getting checked out by your doctor
. Normally your hair follicles cycle at different times and you shed a constant, low-level amount of hair. However, when the body undergoes stress - which can be due to weight loss, emotional stresses, surgeries - sometimes the hair follicles all sync up and die at the same time, causing more diffuse hair loss
. For most people this is temporary and the hair eventually grows back and enters a more normal growth cycle.
That being said, I would still go see your doctor to get checked out, for several reasons. One, while it's clear that you made some pretty big dietary changes, it's important to make sure that there isn't an underlying cause of both your weight loss and your hair loss. Second, assuming that all of this is related to your diet, I would discuss your current diet with your doctor to make sure that you're eating a balanced diet and not deficient in any important nutrients or vitamins.