Amy Barnes went from 490 to 150 lbs. Hear what she thinks is the most important thing on a weight-loss plan.

Also take note of Tosca Reno's "Eat Clean" Principles:

-Eat more -- eat 6 small meals each day.

-Eat breakfast every day, within an hour of rising.

-Eat a combination of lean protein and complex carbohydrates at each meal.

-Eat sufficient (2-3) healthy fats every day.

-Drink 2-3 liters of water each day.

-Carry a cooler packed with Clean foods each day.

-Depend on fresh fruits and vegetables for fiber, vitamins, nutrients and enzymes.

-Adhere to proper portion sizes.

What to Avoid:

-Avoid all over-processed foods, particularly white flour and sugar.

-Avoid chemically charged foods.

-Avoid foods containing preservatives.

-Avoid artificial sugars.

-Avoid artificial (foods such as processed cheese slices).

-Avoid saturated and trans fats.

-Avoid sugar-loaded beverages, including colas and juices.

-Avoid (or do your best to limit) alcohol intake.

-Avoid all calorie-dense foods containing little or no nutritional value. I call these anti-foods.

-Avoid super-sizing your meals.