We should have 3 meals a day totaling 2,000 calories for women and 2,500 for men. When you time big meals like those is important. If you exercise in the mornings before work you may get away with just making sure you're well hydrated. This is because you may not even have time for breakfast before you run but can have it after.
Most people workout in the evening after work. If you finish your work at 5 pm for example and you workout at 6 pm. You would have had lunch at 1 or 2 pm this gives you time to have a proper lunch and for it to digest enough and give you energy for your workout. So give it 2 to 3 hours for a main meal.
You should wait 1 to 2 hours for a light meal like a sandwich with some protein in the filling like chicken or turkey. Eating afterwards is very important too. If you've done a workout of lots of intensity you need to consume protein within 30 minutes. Something like a meat sandwich or a protein shake. This helps your muscles recover.
There might be a time when you're hungry and you're going to workout soon. You would need some carbs to get you through the workout you've got coming up. For example if this is about an hour before your exercise. A snack on this occasion would be the perfect choice. You need something to eat but nothing substantial.
For example a good pre-workout snack would be peanut butter and sliced banana on toast. This would give you carbs that release their energy slowly while the fruit releases it's energy quicker. Smoothies make a great snack as does most fruit with oatmeal. If you're trying to lose weight by exercising make sure you moderate yourself on the snacks to maintain your regimen.
Drinking liquids to support your workout is so important that we better include it here. You even need to time your liquid intake around your workouts too. The last thing you need is to be dehydrated before your run. Keep drinking water throughout the day when you feel thirsty. This is especially so for a morning workout as you may be dehydrated when you wake up.
Within an hour of your workout you need to take on some liquid. We recommend 16 ounces. Then go by your thirst and this includes while you're working out. So there you have when and what you should eat and drink before you get on a treadmill. In summary, always go by the intensity of the workout you've got coming and you'll enjoy that workout even more.
Timing of your meals is very important. You need to get enough nutrients in you to exercise. Don't skip a meal, especially if you're trying to lose weight. You need to have 3 main meals and 2 light snacks per day. As I've said before, you need to think about eating and when you exercise and time it all appropriately.
I like to get my running in just before my main evening meal. This way I've eaten 2 meals before so I have enough energy. I can do a long run or whatever my schedule to do that day is, knowing that I'm just about to take on a main meal. This will refuel me and give me enough down time to be able to get to sleep well that night.
After a while you too will find a routine that works. Whether you go out to work and maybe you do your treadmill runs in a gym. Get your body used to taking on food in time for exercising. You don't have to workout everyday and you're not really advised to. Just be sure you eat enough to sustain your running and you'll be ok.