Differences Between Simple Sugars & Starches

High-carb foods have a bad reputation because of their high sugar content. However, not all carbs are created equal, and there's a big difference between starch and sugar. Starchy foods may actually improve glycemic control and support weight loss when consumed in moderation.

Take any health magazine or read any health blog and you'll notice a clear distinction between "good" and "bad" carbs. Contrary to what you may have heard, carbohydrates are not evil. Along with protein and fats, these nutrients fuel your energy and support the proper functioning of your body. Several types of carbs exist and each has unique properties, as the American Diabetes Association points out.

Many dieters mistakenly believe that carbs and sugars are the same. While it's true that sugar is a type of carbohydrate, not all carbs are sugars. Fiber and starch are carbs too — and they have a different impact on your health and blood glucose levels than simple sugars.

​Read more:​ 16 Diet-Friendly Healthful Carbs

So, what's the difference between starch and sugar? Beans, peas, potatoes and whole grains are all starchy foods, notes the American Diabetes Association. Soft drinks, cookies, chocolate, candies and other processed foods contain simple sugars. Most fruits contain simple sugars too — but in the form of fructose. They're also rich in fiber, another type of carbohydrate, which slows sugar absorption into the bloodstream.

To put it simply, carbohydrates include fiber, sugar and starch. According to the Glycemic Index Foundation and other health organizations, glucose, sucrose and fructose, which are referred to as simple carbs, contain a single sugar molecule. Lactose, a natural sugar in milk and dairy, consists of glucose and galactose. Starches, on the other hand, can be defined as long chains of glucose molecules.

Unlike sugars and starches, fiber cannot be digested and remains intact in the gastrointestinal (GI) tract. It adds bulk to your stool and helps move food through the digestive system, keeping you regular.

The main types of dietary fiber include soluble and insoluble fiber as well as resistant starch. The latter is not digested in the GI tract, so it doesn't impact blood sugar levels. This type of fiber feeds the "good" gut bacteria, prevents constipation and increases satiety, according to the Johns Hopkins University.

As you see, both starches and sugars are examples of carbohydrates. However, each has a different impact on your health and wellbeing. The 2015-2020 Dietary Guidelines recommend the consumption of vegetables, legumes and other foods rich in starch. Added sugar, on the other hand, should not exceed 10 percent of your daily calories, or 9 teaspoons per day for men and 6 teaspoons for women.

Starchy foods like whole wheat, whole-grain bread, whole pasta and potatoes are rich in fiber and other nutrients, such as iron, calcium and B-complex vitamins. Simple carbs, including sugar, do provide calories (4 per gram) but lack nutritional value, points out the American Heart Association. The only exceptions are natural sugars, such as fructose and lactose. Fruits, milk, yogurt, cheese and other whole foods containing these sugars are typically high in nutrients.

Amy Campbell, MS, RD at the Joslin Diabetes Center states that starchy foods are the body's main source of fuel. Even if you have diabetes, you still need these carbs in your diet. Ideally, choose whole and minimally processed starchy foods with high fiber content. Those containing resistant starch are particularly beneficial as they may help reduce oxidative stress and improve blood sugar control in people with diabetes.

​Read more:​ 19 High-Fiber Foods — Some May Surprise You!

Simple sugars cause blood sugar spikes followed by crashes, warns the American Heart Association. Think about how you feel after eating cookies or breakfast cereals in the morning. You're energized and ready for the day ahead, but your energy levels drop around noon. A bowl of oatmeal, on the other hand, provides steady energy and keeps you full longer due to its high-fiber content.