First of all, congratulations on trying to lose weight. Maintaining a healthy weight is an important part of ensuring your longer term health.
Aerobic exercise (cardio) is a very important part of weight loss
. The recommendation is that you should perform at least 30-60 minutes on most days of the week at an intensity that at least raises your heart rate and makes you sweat. If you are doing this already, then you are well on your way.
I do discourage the high protein Atkin's style diet. This is a fad diet, and it is not helpful over the long term. This is because, instead of helping you learn to eat healthy balanced meals, it just replaces one set of unhealthy eating habits (your old habits) with a new set of unhealthy eating habits (eating only protein). Most people who use the Atkin's style diet will lose weight initially, but the diet is not sustainable and so the weight does tend to come right back.
A better alternative would be to set up an appointment with a dietitian
, who can make an assessment of your eating habits and weight loss goals and come up with a realistic, sensible meal plan.