Easy starter: no soda pop, not even diet (nothing but pure chemicals - Splenda is the Devil!). No processed meats, stick to lots of lean cuts with side salad. No fast food, stick to all fresh/organic food. Basically eat like a "caveman". If it's not fresh and chemical free, don't eat it.
Stop taking the elavator, take the stairs. As BobG said, speed walk at least one mile a day, it's only 15 minutes of your life and there's no excuse not to do it.
99% of the fruitjuice out there is nothing but Koolaid - color and sugar. Drink water, 2% milk, and whole juices (buy a juicer). The more water you drink, the more you'll crave it and it'll satisfy your thirst. I tried to drink a Coke the other day and thought it tasted like crap, and I used to drink 1 or 2 every day years ago.
The more you exercise and lay off the chemicals, the more energy you'll have.
