Hi there. It wouldn't be healthy to lose 30 pounds in a month for most people. It took a long time to gain it--- it should take a decent amount of time to lose it for it to stay off.
Restrictive and fad diets can give you a quick weight loss but studies show that this weight goes right back on and usually with more pounds added from where you started.
Better to take a more long term approach and try to modify your lifestyle.
Awesome that you are active! Then it sounds like eating is where you need some help. Lean protein, vegi's and fruits should be the vast majority of your diet. Limit portions, cut out unnecessary empty calories, and carb loading.
But it would help to know what things you are wanting to change in order to lose this weight?
Here is the answer to this question. In order to lose weight, you have to subtract calories. Safe weight loss is 1-2 lbs/week, so in order to lose 1 lb/week, you'd have to drop 500 calories from your BMR each day (1 lb is equal to 3500 calories, so 500 calories X 7 days = 3500 calories or 1 lb). OR you can drop 250 calories from your diet and increase .....