If I want to lose weight I know that I have to eat 1200 calories. Is it really all about calories? Does macronutrient content have an impact on weightloss? For instance, if I eat 1200 calories and it's all fat will I still lose weight? So confuseddddd...
Yes, macronutrient content has a very important impact on weight loss.
High glycemic index (GI) foods (grains, pasta, rice, potatoes, sugar, candy...) raise your insulin levels. Insulin is a fat storage hormone: it blocks existing fat from being burned for energy as well as instructing the body to store as much as possible of whatever was just eaten as fat. So, you can go into calorie deficit and still not lose weight at all if you keep eating high GI foods. You will feel like you are starving because you are: your body will be unable to access the vast reserves of fat for energy (to make up the balance of your calorie deficit).
On the other hand, if you eliminate high GI foods from your diet, your insulin levels will remain low after every meal. Low insulin levels allows the body to access stored fat for energy, and if you have a calorie deficit then this is exactly what will happen. You will burn fat without even trying, simply because your insulin is low after meals and your body needs more energy to operate as you are not eating enough. Stored fat will be used, just to have the energy to keep on breathing.
I lost 55 lbs without exercising at all, and without feeling hungry at all. I simply stopped eating high GI foods. I've only recently started exercising during the past month or two, now that I don't have so much to carry around...
The key to weight loss is managing your insulin. Or as they say "Abs are born in the kitchen, not the gym"... 80% correct food intake, 20% exercise, that's the approximate formula for the six-pack.