How to lose a lot of weight (belly fat). Eat very healthy at the same time and ride lifecycle till summer?

YEP! Losing weight is simple math. If you burn more calories than you ingest, you will loss weight. A two pronged attack, involving eating less calories and exercising more, is most effective. Be careful, attempts to loss too much weight too fast are not advisable. Most people should not try to loss more than a 1 #/week. Not only is that not sustainable and doom to fail, it is not safe or healthy.