The primary sources of bad or nutritionally undesirable carbohydrates are sugars, especially added sugars, and refined grains. Added sugar and refined grains are common ingredients in breakfast cereals, sweetened soft drinks, candies, baked goods and processed foods.
While some simple sugars are natural components of fruit, vegetables and dairy products, food manufacturers add sugar to many foods to improve the taste, texture and appearance. Consumers can find out if a food contains added sugar by reading the ingredient list on its label. Commonly added sweeteners include sugar, brown sugar, high-fructose corn syrup, honey, molasses and fruit juice concentrates. Other sweeteners include lactose, maltose, fructose, dextrose and glucose. The higher up in the ingredients list a sweetener appears, the more of it there is in the food.
Sugars and refined grains are simple carbohydrates. They supply quick energy to the body but are low on fiber and other nutrients. Complex carbohydrates, commonly referred to as good carbs, break down more slowly in the body because of their fiber content and don't cause spikes in blood sugar. They are also usually richer in vitamins, minerals and phytochemicals than simple carbohydrates. Good sources of complex carbohydrates include whole grains, vegetables, fruits and legumes.