Don't go on a diet. Change your attitude towards food and lose fat and gain muscle. Later on you might need to increase your protein intake and go for some protein shakes but you should find this basic eating plan works for a while. Ask your questions later when you get into it.
Never go hungry and eat several times per day. Don't deny yourself treats completely. If you need the energy then have it. You get fat if you eat for comfort and not when you need it. Your 2000 maintenance calories per day should be healthy foods then add a bar of chocolate and a few biscuits on top or a little of your favourite food. Pizza and pastries are out.
Don't count calories and don't count how many times you eat. The idea is to know subconsciously that you are eating several times per day and not think about food. It's good if you eat smaller meals and have more snacks or add another small meal in between.
Eat healthy food & lots of fruit and veg. Include natural foods containing fat- nuts, avocado, oily fish, eggs. Then eat everything else low fat (but not zero fat)and low sugar-lean meats, bran or oat cereal, 2% milk, 2% fat yoghurt, low fat cream cheese, no sugary drinks except when training, Eat every kind of fruit you can find - not just apples and oranges. Don't be afraid to use a little oil on your salad and to use a little for cooking - get a variety of interesting oils - the more interesting the better it is for you - e.g. walnut, sesame. Don't eat fast food or breaded chicken. If you do then don't have fries with it. Eat snacks throughout the day e.g dried fruit and nuts ( something like brazil nuts, English walnuts (omega 3), almonds, cranberries, apricots NOT peanuts and raisins or something with protein in it). Get smoothies instead of ordinary fruit juice. Don't eat too much bread - if you do go for whole grain bread.
Read about healthy eating and open your mind a bit.
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I started doing this buying ready made salads and freshly cooked healthy meals and semi prepared foods, sauces, barbequed chicken - I eat a tiny bit of the skin with it. I buy all the exotic fruit I could find. Sometimes I get take away chinese mixed veg to have with main meal( if you have veg it doesn't matter if there is a bit of oil in it as long as it's not dripping in fat).
It's better to buy if you don't feel like cooking or you might find you don't eat the right foods.