Eating the daily required food groups will help the body receive the good nutrients it needs without gaining weight this includes legumes , fruits and vegetables 5 times daily , sea food,high fiber diet ( unless if you have irritable bowel syndrome which needs to have soluble fruits and fibers).
Drink plenty of water. The recommended amount is 8 glasses per day.
Drinking plenty of liquids will help flush and eliminate toxins and impurities from the body.