Smoothies can easily provide a significant portion of the vitamins and minerals you need on a daily basis. But if not prepared in the right way, they can end up having a negative effect on your weight, your blood sugar levels, etc.

So before you plug in your blender or head down to the store, follow these tips to make sure your smoothie is as healthy as can be:  

1. Don't go overboard with fruits

"It’s easy to toss a handful of berries, and every other leftover fruit you have in the refrigerator," registered dietitian Toby Amidor stated.

But there is a limit on how much fruit we should consume in a day, with most health experts recommending no more than 2 to 4 daily servings.

So try to follow a limit of 1 cup of fruit per smoothie serving. Also, consider adding more green vegetables such as spinach, beet greens, kale, and collard greens. Not only do they come packed with nutrients, they also have minimal impact on blood glucose.

2. Choose the right kind of milk 

While whole fat milk has been found to be safe and healthy in recent research, dietitians do believe non-fat or low-fat dairy milk is a better choice for smoothies. This definitely applies when adding ingredients like avocados or nuts which are quite rich in terms of fat content.

People who are lactose intolerant can opt for almond milk or soy milk instead. However, make sure to check the nutrition labels and pick up the unsweetened type. Certain varieties of non-dairy milk can be sneakily loaded with added sugar. 

3. Invest in a high-quality blender

"The most common mistake people make is using a blender with no power," said celebrity trainer and author Harley Pasternak. "The majority of household blenders can't get frozen fruits smooth, or chop through seeds, so you get a smoothie that's not very smooth."

And if you happen to consume the healthy beverage on the regular, specialized blenders are available today that come with a convenient smoothie setting. Pasternak recommends buying one that comes with a "tamper," which pushes floating foods to the blades and helps create a thicker blend.

4. Yes, portion control still matters

Just because smoothies are categorized under healthy beverages does not mean they get a free pass when it comes to portion control.

"Fill your blender to the rim and you’ll get one sizable smoothie that can weigh in between 400 to 600 calories or more!" Amidor stated.

One smoothie should be no more than 8 to 10 ounces, according to Leah Groppo, a clinical dietitian at Stanford Health Care. If you happen to order one which goes way over this range, you can try to split it with a friend or simply drink half and freeze the rest of it for later use.