If you feel that you should be eating healthier but think its "too expensive", here are some things you could toss away to save money and accomplish your goals:
1) Cable TV
Your life is a lot more exciting than what's on TV! If there's a couple shows you like, watch them on the internet!
Take public transportation. The machine you live in is way more important than a machine you drive; your body's fuel is more important than a machine's fuel (when did that priority get switched around?) Also, if you wouldn't put gravel in your car's tank, you shouldn't be putting junk food in yours (see #3).
3) Junk food
Despite your relationship with its product, that company doesn't love you nor does it care about your personal life or your future. All they want is your money and they don't care how they will get it, even if it means using lots of chemicals, stimulants, and horribly processed ingredients which will addict you and give you many health problems. You are worth it! Just say no!
4) Cell phone
You can learn a lot more about someone during a bike ride than a phone conversation. Get a land line, and if you think you need a cell phone for emergencies, then get one with prepaid minutes and use it just for that.
5) Eating out
If you have $10, spend it on buying 7 pounds of organic fruit versus 1 pound of mash at a restaurant.
6) Beauty products
"It's the inside that counts" means just as much physically as it does spiritually.
7) Where you live
In my opinion, life with the bare essentials (heating, clothing, and good food) is far better than "living at large", if the former means great health and vitality but the latter means living every day with the same worn-down feeling. If you can't afford better food but a lot of your money is going to rent, then consider moving. Moving to a smaller place isn't as bad as moving to the hospital.
Movies, events, shows, etc. These things might be great, but odds are you'll find equal or greater satisfaction with the right people using your imaginations to have fun for free.
That's all for now. None of these things are inherently bad, but they are luxuries and the comfort that they can provide is secondary to the comfort of a healthy body and an active (lively) lifestyle. Just experiment with your life a little; I bet you'll enjoy the results. Good luck.
Deuteronomy 8:10 - When you have eaten and are satisfied, praise the LORD your God for the good land he has given you.