Preparing a healthy meal can be time-consuming.

And even when you do have some extra time at home, like on the weekends or if you work from home, you still don't necessarily have time to stand over your stove or oven — stirring, flipping, sautéing, boiling, simmering...and the list goes on. And don't even get me started on holiday cooking, when — sure, you have "time" — but you also have more side dishes to cook than one person can realistically handle.

Enter: The slow cooker. Possibly one of the best ways to take the pressure out of cooking a healthy meal that can also feed the whole family, be stored away as a heat-and-serve lunch option during a busy week, or simply simplify your holiday cooking logistics.

Whether you're a slow cooker newbie like me or a veteran user questioning the ingredient list of your favorite slow cooker recipe, Kylie Arrindell, wellness dietitian at Houston Methodist, is here to talk all things healthy when it comes to slow cooker cooking.

Here's how a slow cooker works

Arrindell: A slow cooker is a great cooking method for someone who's busy and wants to prepare easy meals without having to spend a lot of time in the kitchen. It's the "set it and forget it" kind of meal preparation method that cooks your food for multiple hours, hence the name "slow cooker."

Most slow cookers have timers that allow for a meal to be slow cooked throughout the day — but not overcooked — and then switched to a "warm" setting so the food remains hot and safe to eat. To maximize the taste and texture of your meal and to avoid overcooking, it's important to follow the indicated cooking times on the recipe you're following. But, if you get delayed for an hour or so, your slow cooker meal is probably okay for a couple of hours if it defaults to the warm setting once it is finished cooking.

Here's why a slow cooker is good for cooking healthy

Arrindell: One of the great things about a slow cooker is that, depending on its size, you might be able to cook a well-balanced meal — including protein, carbs and vegetables — all in the same pot. (Although, you may not be able to add everything into your cooker all at once, since different foods have different cooking times). And because you're typically cooking with broth or other flavorful liquids, using a slow cooker is also a great way to keep lean cuts of meat tender and juicy.

You can use a slow cooker for batch cooking or meal prep, as well as when you have leftover veggies, beans or meats and want to make a stew or soup.

I love to use my slow cooker to make a roast with onions, potatoes, green beans and carrots — adding some garlic and rosemary to help flavor the meal without adding any salt. Another favorite of mine is lemon garlic chicken with carrots, celery, peas and wild rice or quinoa. For a quick lunch-for-the-week meal, I love shredded chicken fajitas that include a lot of bell pepper and onion.

Not every slow cooker recipe is equally healthy

Arrindell: Like every cooking method, there's almost always a way to make a meal that trends toward unhealthy — slow cooker cooking included.

When scanning a slow cooker recipe, watch out for too many:

• High-fat ingredients, such as cream-based soups, cream cheese and butter
• High-sodium ingredients, such as canned vegetables, broths, soups or beans
• High-carb, low-veggie ingredient lists, such as pastas or casserole-like dishes
  
  

In addition, if you choose a slow cooker recipe that's meat-heavy, such as pulled pork, be sure to have plenty of veggies as a side to complete your well-balanced meal.

The good news, however, is that — with a little planning — almost any recipe can be modified to reduce its fat, sodium, sugar or carbohydrate content.

Ingredient substitutions that can make any slow cooker recipe healthier

Arrindell: If you stumble on a slow cooker recipe you want to try, but it contains some of the unhealthier ingredients above, you can almost always make some healthier substitutions!

Here are some substitutions and other ideas to help boost the healthfulness of your slow cooker dish:

• Choose whole-grain options over refined carbohydrates. For instance, swap white pasta with whole-grain pasta or beans. Whole-grain choices add both fiber and protein to your dish.
  
  
• Rinse and drain canned vegetables and beans. Canned items are typically high in sodium, and draining the liquid can help lower the sodium content.
  
  
• Replace mayonnaise with Greek yogurt. Given their similar textures and cooking behaviors, this swap gives you less fat and more protein.
  
  
• Cut the cheese. Many recipes call for multiple cups of cheese, but you can typically cut this amount, and therefore the fat (and sodium) content, by half.
  
  
• More herbs, less salt. To help pack a flavorful punch while staying healthy, opt for fresh or dried herbs instead of more salt.
  
  
• Add extra veggies.* You always want to incorporate vegetables into your meal, whether that means cooking them in the slow cooker or preparing them another way. Bagged salad is nice to have on hand to add some color and nutrients to your meal.
  
  

*Be advised: Some vegetables are delicate and don't stand up to being cooked in a slow cooker for hours upon hours, as they become too soft and lose their flavor or texture (looking at you, zucchini squash). On the flip side, onions, broccoli, green beans, bell peppers and celery hold up well in a slow cooker.

Some final slow cooker tips (just in case you need 'em)

Arrindell: Cooking with a new kitchen gadget can be intimidating, but here are a few tips if you're just getting started.

1. Avoid "The Danger Zone"

It's important to make sure your food doesn't enter the temperature range where bacteria can grow, which falls between 40 and 140 degrees Fahrenheit. Generally, most slow cookers can hold a temperature on the warm setting between 145 and 165 degrees Fahrenheit for two to four hours (check your slow cooker manual for your model's specifications). But, I always err on the side of caution, only keeping food on the warm setting (after it's fully cooked) for two hours at most. I also recommend checking the food's internal temperature with a food thermometer to make sure it's thoroughly cooked.

2. Preheat your slow cooker

Just like when you're using an oven, you don't want raw food to spend a lot of time in "The Danger Zone" as your cooker starts the process of coming up to temperature. Instead of just throwing everything in and then pressing "Start," you'll want to preheat your slow cooker. In addition, if your meat is frozen, make sure it's safely thawed before adding to your slow cooker.

3. Your slow cooker can't cook on "Warm"

Don't attempt to cook meat on the "Warm" setting — it won't get hot enough. It's also a good idea to keep the lid on as much as possible in order to not only retain heat, but also moisture.