The fundamentals of eating clean encourage you to consume more whole foods — such as fruits, vegetables, lean proteins, whole grains and healthy fats — and limit highly processed snack foods, sweets and other packaged foods. An example of a meal containing all of these foods would be a spinach salad with grilled chicken, quinoa, avocado, walnuts and apple slices.

Other tips for eating clean include:

• Limiting highly processed, packaged foods with a long list of ingredients, most of which are not natural. Ingredients listed on the food label should mostly be foods that you recognize, such as whole-grain steel cut oats, dried apple, flaxseed and cinnamon. Limit ingredients that you can't identify or can't easily pronounce, such as carnauba wax, soy lecithin and artificial flavor.
• Cutting back on foods with added salt, sugar or fat.

• Avoiding foods that are drastically altered compared with their natural form, such as apple juice versus a whole apple, chicken nuggets versus a fresh chicken breast, or vegetable chips versus fresh vegetables.

  Sometimes processing can be a good thing for foods, such as pasteurization that makes eggs and dairy products safe for consumption. Also, frozen fruits and vegetables are OK because they are minimally processed and can sometimes contain more nutrients than fresh varieties since they are frozen at their peak.

• Preparing and eating more foods at home. Start with simple meals to help you get into the habit, such as Greek yogurt and fresh berries for breakfast, or a whole-grain roasted turkey and avocado wrap with red pepper slices at lunch.

Clean eating isn't black and white. There's room for flexibility and modifications, and it doesn't require avoiding any certain food groups — unless medically necessary.

Clean eating also doesn't mean that all foods must be consumed in the raw state. Cooking, pasteurizing and preserving are OK.

Replacing meals with store-bought protein shakes or sugary smoothies and juices is not an example of clean eating.