Strategy to Lose Weight

I have to consume food according to what I have eaten.  Should I eat according to the PCOS, which has its own complications including diabetes, high blood pressure, obesity, and blood sugar?  Should I eat according to the diabetes, which has its own complications in itself?  What should my strategy for weight loss be?  I didn't eat much today but I should have laid off of the cereal and the penne and cheese.  Other than that, I think I did well today.