1. Following a Healthy Diet
Drink plenty of water.
Don't eat anything for two to three hours before sleep.
Try to cut as much sugar from your diet as possible.
Reduce your portion sizes and eat more frequently.
Eat lots of lean protein, Eat whole grains, Eat low-fat dairy products and Eat healthy fats.
Lower your sodium intake.
2. Exercising for a Flat Stomach
Do Aerobic Exercises Daily.
Include plyometrics.
Incorporate strength training to build muscle.
3. Living Healthy
Consult with an expert.
Don't do fad diets.
Never starve yourself.
Learn to cope with stress.
Get enough sleep so that you won't feel tired all the time.