Okay so this is something that will be obvious but I'll say it anyway.
Avoid these two items in your food. Aspartame and High Fructose Corn Syrup.
You may know Aspartame more as low calorie sweetners such as Nutrasweet, but let me tell you it is healthier to have real sugar in your body than that disgusting crap. And yes that means NO diet soda, boo hoo. Trust me though, drink water and juice. Those are much healthier.
Also with High Fructose Corn Syrup, this stuff is equally bad for you and a lot of companies put it in almost everything. I suggest you actively take the time to read your product labels and try to avoid this stuff. It basically adds empty calories to everything it is in.
Thats todays tip.