What you eat before and after your workout will depend on your goals and the type of workouts you do.
Before Your Cardio Workout
If your workout is first thing in the morning, I recommend not eating anything (if you can). Your body is already depleted of carbohydrates after a long period of not eating. This means that your body will use more stored fat for energy rather than carbohydrates. This is best for low to moderate intensity cardio such as power walking or light jogging.
If you are doing high intensity cardio such as a long distance run or sprints, it may be better for you to eat something small. This is because without the carbohydrates, you will have less energy so it will be more difficult for you to train hard. If you don’t care about training hard and just want fat loss, don’t eat (it will be tough). But if you are training for an event or really want to push yourself during your workout, eat something high in carbohydrates such as a piece of fruit.
Before Your HIIT / Weights Workout
Before this type of workout, I recommend eating something small. This type of workout will use up stored carbohydrates (glycogen), so if you haven’t eaten anything before hand, this workout will feel very difficult. Again, I recommend something small and high in carbs such as a piece of fruit.
After Your Workouts
After any workout is the absolute BEST time to eat carbs. Your body has used a lot of stored carbohydrates (glycogen) during the workout, and will use the carbs you eat to replenish the glycogen in your muscles, rather than store it as fat. This is the only time of the day that you have this opportunity. You have about 90 minutes post workout to eat these carbs to get the best benefit.
I also recommend eating protein post workout to help your muscles recover. Ideally, carbohydrate to protein ratio should be 3:1. My favourite post workout meal is a protein smoothie with fruit and protein powder (in the morning), or BBQ chicken with roast sweet or white potato and green vegetables (at night).