An effective workout depends on various factors, the most important among them is the diet that you consume. What you actually have before a working out pattern would very well prepare your body to deal with stress levels and the meal after that is responsible for muscle repair and body building.
Get the carbs: treat your body with some carbohydrates an hour before you make it to the gym. Do have some fruits, apple would be ideal. Toasts, cornflakes and idlis would be an ideal diet. You could also have a banana for the complex carbohydrates it provides. Drink a glass of water to keep yourself well hydrated.
Never go hungry: Never hit a gym on an empty stomach. This can adversely affect your overall health.
After a heavy meal: Normal individuals have to keep a gap of about two to three hours between a workout and heavy meal. But, for a diabetic it is important to workout soon after a heavy meal.
Use the window: During the workout sessions, the level of a hormone called, cortisol increase in your body that makes it more prone to infections. That's why the hour just after a workout is known as the 'window period', as it allows for infections to enter the body. Use this opportunity and eat as soon as possible.
Get a drink: The body loses salt due to sweating. That is why it's very important to compensate via a rich source of electrolyte such as ORT.
Create supplements: The body needs a high-protein diet for muscle building.
Have protiens, but: Protiens are difficult to get digested fast. So do not rely on them completely. Include a lot of greens in your diet.