You can get complex carbs in things like whole grain flower, oats, grains, and vegetables. Simple carbs are processed quickly by the body, and are almost useless. They come in sugar and processed flour. Likewise, fat is divided into different types. Eating fatty does not make you fat ? but the wrong types of fat can give you health problems. So, be sure to watch what you put in your mouth.
Breaking your bad habits is the hardest part of a healthy diet. Think about the unhealthy foods that you partake in the most often. Think about the good effects they have on your body, and try to think of something that could do the same thing in a better way. Do you come up with a bunch of foods that would be better for you? Maybe it's time to switch. Stop getting a donut every morning just because your work offers them. Fix some bacon and eggs at home instead, and you'll get many more health benefits. It takes some willpower to change your habits for good, but if you truly have the desire to eat healthily then you should be willing to do what it takes.
Finally, you need to place great importance on exercise. Exercising daily is the most important thing to do, and the best way to stay healthy. Before work every day, at the very least take a half-hour walk around the neighborhood. You could even progress up to jogging or full-on running. If you don't regularly exercise, you will be amazed be the effects it has on your day-to-day life. By waking yourself up the right way in the morning, you'll have extra energy all throughout the day, and you'll probably sleep better that night.
Living a healthy lifestyle is never easy, especially if your unhealthy habits are deeply entrenched. But all you have to do is change one thing at a time until you're a better person.