I don't know why  I am not losing weight for 3 weeks I am eating less than 1200 calories(100g whey protein+100g casein protein+80g of Dark Chocolate bar 350kal) so baisiclly I am having 4 Protein Shakes(each has 25g whey+25g casein)+Chocologic No Added Sugar Dark Chocolate 80Gr Daily and still no weight loss..I am 22,170cm,65kg, I do HIIT 4 times a week 30min session + 3 times a week weight training(60-120min).....I have no cheat days/meals or anything like that.. HELP! PLEASE?

That's not a very good diet. Calories are too low and not much micronutrients. Drinking 4 scoops of protein to cover most of calories and protein needs is not the way to go.

Check out the meal plan page, enter your information and start at a 200 calorie deficit. SLOWLY lower your carbs every week and slowly add in cardio. Aim for 1lb of weight loss per week.

Thank you for the advice will keep in mind,however this does not help me with my question witch is: Why I am not lossing weight even if I am in a big caloric deficit??

The human body likes being in homeostasis. It will do whatever it needs to do to function. That includes holding on to as many calories as possible when there aren't many calories coming in.

Darius,

You have stopped losing weight because your body thinks it is starving and has gone into survival mode and slowed your metabolism. A healthy active male should NEVER drop calories below 1500/day. You are also micro-nutrient deficient as the calories you are eating are not dense enough nutritionally.

Supplements are NOT meal replacements - they are meant to supplement your meals. By not eating enough nutritious food, drinking protein shakes, and doing HIIT cardio, you are in a catabolic state whereby you are losing muscle (which is very bad when trying to lose fat weight) and your body is starving and gone into survival mode.

My suggestion is to get your calories up around 1800 and you should be getting at least 2 nutrient dense meals of REAL food not protein shakes. Nutrient dense food is non man-made and non processed - basically all food sold in its natural state that you must prepare yourself. I would then supplement these meals with 1 or 2 protein shakes not 4.

I would also focus more on resistance training versus HIIT. The more muscle mass you have the more calories you burn and the less cardio you need to do. All cardio is slightly catabolic. HIIT is the one exception as it is done intensely and for not more than 10-15 minutes if done correctly. Long steady state cardio eats muscle while it builds endurance. It is not required to get lean if your nutrition and training are on point - regardless of what bro-science says. When you do HIIT, I would do no more than 2 sessions a week. That is all that is needed. If you get all this on target, your weight may stay the same but you will be trading fat for muscle which is more important than what the scale says. You need to monitor your body fat more than your body weight to makes sure your program is working.

John