When trying to keep a flat stomach, you need to try and minimize your intakes and this means that you need to minimize the amount of fat and other items that you put in your body.
Normally, this is very hard to do since every food item that you eat has a lot of fat and other things in it.
This is why it is probably a smart idea to go ahead and eat as many nuts as you can. They are high in protein content and have very little to no side effects, especially for people trying to lose weight or maintain a figure.
Another option that you have to eating a lot of food, is to try and move on to a liquid diet. A liquid diet would see you drinking more fluids, compared to the food that you would be eating on a normal basis.
However, instead of just drinking water, you can get special supplement fluids that have all the minerals and nourishing items that are needed to keep your body going.
At the same time, you should also be drinking more water, since it will stop you from over eating, or eating more than you should. All the water that you do drink, will simply pass through your body.
The last thing that you should try doing, is to fit in more organic meals in your day to day diet. Eating healthy is going to help you stay fit, and will help you keep a flat stomach as well.
This is why you should try and eat as many organic meals as you can, as opposed to eating unhealthy oiled up, fried food.