As it happens, the old adage, “you are what you eat” usually holds true. What we consume and how we consume it affects how the trillions of cells in our bodies function. For students especially, eating has the ability to influence our mood, sleeping patterns, energy levels, and immune systems, all of which can be affected by the lack of sleep, exam stress, and lack of self-care students tend to experience.

In order to optimize the functioning of our brain and body, we have to start with what we’re feeding our cells. This means cleaning up the way we eat.

The concept of “clean eating” emerged out of programs like the South Beach Diet and gluten-free trend which advocate for eating more or less of a certain type of nutrient — like carbs or protein. The basis of clean eating is to consume food in the most natural and unrefined state possible. Although the concept has received a bad reputation for being too restrictive and expensive, basic principles of clean eating — like choosing foods that are nutritious and unprocessed — are changes we can all benefit from.

To get everyone started on their journey to optimum health, here are five ways you can clean up your diet.

1. Avoid packaged foods

Although not all packaged foods are bad, like chickpeas and oats, most foods that come in a package are heavily processed. Many processed foods contain additives, preservatives, excess sugar, and sodium. These can have negative effects on our health — not to mention our waistlines. One way to distinguish between “good” packaged foods and “bad” packaged foods is to look at the ingredient list. If the list is full of ingredients you can’t pronounce or is longer than 10 ingredients, it’s best to leave it on the shelf.

Tip: Prepare your meals at the start of every week so you don’t feel the need to buy something fast or pre-packaged when you’re running between classes.

2. Hydrate with water

Juice and soda may momentarily quench your thirst, but these beverages cannot replace the superpowers of water. It’s very easy for students to get caught up in busy routines and forget to stay hydrated, but drinking regular amounts of water throughout the day is important for optimizing your health. The amount of water you should drink in a day depends on your activity level, but the standard is generally eight to ten glasses. Staying hydrated with water is crucial for eliminating toxins from your body, keeping your energy high, and your mind sharp.

Tip: Carry around a large, measured water bottle so you can keep track of how much water you’re drinking throughout the day, making you more conscious of staying hydrated.

3. Fill up on veggies

Vegetables contain essential vitamins and nutrients that are necessary to keep us looking and feeling our best. They also contain fiber, which is not only vital for maintaining a healthy digestive system, but also helps you feel full longer. Besides the nutritional value, one of the advantages of loading up on veggies is that they’re low in calories, so you can eat large portions without worrying about the scale. Adding a serving of vegetables to each meal will do wonders for your body and immune system.

Tip: Vegetables can be cooked a number of different ways and can be mixed with a variety of other foods, so get creative and experiment with different recipes!

4. Satisfy your sweet tooth with fruit

A crucial part of clean eating is reducing your sugar intake. Anyone with a sweet tooth knows how difficult avoiding donuts or cookies can be when you get a wicked craving, but swapping unhealthy sweets for nature’s candy is a smart way to curb that craving. Fruit is rich in fiber and essential nutrients. It also contains natural sugars, which makes it a sweet and healthy snack.

Tip: If you find eating plain fruit boring, try mixing it with Greek yogurt and granola, and turn it into a nutritious parfait.

5. Focus on the composition of calories, not just the number of calories

Unfortunately, it’s become mainstream to obsessively count every calorie consumed in a day. 100 calories of candy is very different from 100 calories of vegetables, and your body knows the difference. Rather than focusing solely on how many calories you’re consuming each day, focus on the nutrients you’re consuming. Incorporate a balance of healthy fats, lean protein, and complex carbohydrates within your daily caloric intake and your body will thank you for it.

Tip: Shop the nutrient-rich perimeter of the grocery store, and avoid roaming the isles stocked with packaged and processed foods.