Sucking your fat into your stomach won't do anything useful, because your fat is .. Many people think that holding in their stomach and keeping those muscles.
Believe it or not, you can develop your deep abdominal muscles by sucking in your belly. Exhale completely and then pull your belly button in.
Though the visceral fat that lies behind the abdominal wall makes up only flap of tissue that lies under the belly muscles and blankets the intestines. Don't suck in your gut or pull the tape tight enough to compress the area.