To keep healthy, nutritionists and dietitians recommend a balanced diet and proper exercise. A proper diet means that one gets the right number of carbohydrates, proteins, sugars, and other essential types of food to be able to function properly. Unbalanced diets will naturally lead to weight gain or weight loss, or an unhealthy body. A common phrase that one hears when talking about a balanced diet is glycemic index. More often than not, nutritionists and dietitians encourage the intake of foods with a low glycemic index, especially for diebetic patients and those who are already at risk for diabetes.

But what is a glycemic index?

Glycemic index refers to a number that ranks the effects of carbohydrates of food to one's blood glucose levels. Foods with low glycemic indexes are healthier because the sugars in it are natural. Foods with high glycemic index often contain high fructose corn syrup, maltose, and the like. So what foods have a low glycemic index? Here are 10 tasty examples that you won't realize are actually really healthy and good for you.

1. Apples

While apples tend to be on the sweet side, they're actually low on the glycemic index and contain a lot of fiber, which is great for maintaining a healthy weight. Its glycemic index is 36, Women's Health reports.

2. Brussels sprouts

Speaking of fiber, Brussels sprouts are also high in this nutrient, so you're better off chomping them down when you're watching your weight.

Its GI is only 15.

3. Lettuce

This salad base is high in vitamin C, so you're likely to have a better immune system with regular intake. Its GI is also 15.

4. Red onions

Looking to add zest to that lettuce-based salad? Garnish it with some red onions that have a GI of—you guessed it—15.

5. Tomatoes

Another salad staple, the tomato also has a GI of 15, making for a great meal that contains high levels of vitamin C, The GI Diet reports.

6. Almonds

For snack time, go for almonds, which, according to Women's Health, has a GI of 15 and contains a lot of vitamin E, which is great for the skin. It also has a great combination of protein, fat, and fiber to keep you satiated in between meals.

7. Celery

Another thing you can snack on is celery, which has a GI of 5. It's a great alternative to a bag of chips, as it's natural, tasty, and doesn't have added salt and chemicals, but still packs the crunch.

8. Carrots

This is also a great snack alternative, as it is crunchy, vitamin-filled, and energy boosting. It has a GI of 39.

9. Snow peas or snap peas

If you're into these crunchy greens, then good for you! Substitute your unhealthy chips for some peas that have a GI of 15.

10. Cherries

If you're looking for something on the sweet side to end a meal, have some cherries. They have a GI of 15.