Not all carbs are the same. Many whole foods that are high in carbs are incredibly healthy and nutritious.
On the other hand, refined or simple carbs have had most of the nutrients and fiber removed. Because they are low in fiber and digested quickly, eating refined carbs can cause major swings in blood sugar levels. Eating refined carbs is linked to drastically increased risk of many diseases, including obesity, heart disease and type 2 diabetes. The study also showed that people who ate the most refined carbs were two to three times more likely to get heart disease, compared to those who ate the least. Almost every nutrition expert agrees that refined carbs should be limited.
For more information, click the below link to know what refined carbs are, and why they are bad for your health. Why refined carbs are bad for you