Need to Lose 20Kg

Congratulations on starting your diet! 20 kg is a lofty goal, and should be given a lot of thought to detail to see it through: It will likely be 5-6 months of healthy dieting and exercise to lose this amount of weight, so fasten your seatbelt!
You don't need to eat special foods, but make the better choice every time you eat: baked instead of fried, fruit instead of cookies, and try eating at least 3 meals per day with a healthy snack or two in between. It may help to keep a food diary and see how you usually eat--this will point out times you may not have realized you were eating large portions or very high calorie foods.
Another strategy that will help in the long run is to sit down and come up with a list of 5 reasons why you want to lose weight--be sure to narrow down the general reasons like "look better" or "feel better".. why is this important to you? If you can't come up with concrete reasons that are extremely important to you, it's too easy to give in to the smell of baking pie and just chuck the diet! When you know there's a reason to keep going despite temptation it'll last you till the 20 kg come off.
Plus, if you get into this great habit of healthy eating (instead of a fad diet or starving) and 30 minutes of exercise almost daily (great job!) you'll be able to KEEP that 20 kg off for a long time to come :) Good Luck!

Good Luck, try to eat healthy and start exercising. I lost more than 30 kg walking (5 times a week/1 hour). Do not try to lose weight too fast. Slow is better, you will keep it off.

eating small meals regularly throughout the day should help give you more energy to train. The more muscle i have built, the faster my metabolism and this helps keep the fat off.