Key takeaways
- Starch is a complex carbohydrate and a natural component of many plants, such as fruits, vegetables, and grains, including maize, tapioca, and wheat.
- As well as providing the body with glucose, starchy foods provide a range of vitamins, minerals, fiber, and other nutrients.
- Starchy foods form an essential part of a healthy diet. Starch poses no risks to most people, although people with diabetes may need to moderate their starch intake.
When people hear the word “starch,” they may think of foods rich in carbs, such as potatoes, rice, and pasta. However, most plants store energy as starch, including fruits and vegetables.
Starchy foods are the primary source of carbohydrates for most people. They play a crucial role in a nutritious, well-balanced diet, as they provide the body with glucose, which is the main energy source for every cell.
Foods rich in starch are valuable ingredients in the kitchen, too, as they can thicken soups and sauces without adding fat.
Keep reading to learn more about starch, including the types, the health benefits, and the risks of overeating starchy foods.
Starch, or amylum, is a complex carbohydrate that is naturally found in many foods, mainly grains, legumes, starchy vegetables, and some fruits. In addition, many processed foods contain starches that are extracted from
The extraction of pure starch from food produces a white, tasteless, and odorless powder that does not dissolve in cold water or alcohol.
Starch is a natural polymer, or polysaccharide, meaning that it is a long chain comprising one type of molecule. Starch consists of glucose molecules. It can occur in two forms: amylose and amylopectin.
Amylose is a linear or straight-line polymer that scientists describe as amorphous or solid. Amylopectin forms a branched chain and is crystalline. Different plants contain varying ratios of these units.
Plants create these starch polymers to store the glucose they create during photosynthesis. For this reason, foods that are rich in starch are good sources of energy.
When someone eats food containing starch, the body breaks down the natural polymers into units of glucose, which provide energy throughout the body.
Besides being part of a nutritious diet, various industries — including pharmaceutical, paper, and food — use starch in their manufacturing processes.
Depending on its nutritional characteristics, starch fits into one of three groups:
- Rapidly digestible starch (RDS): RDS exists in cooked foods, such as potatoes and bread. The body rapidly converts it to glucose.
- Slowly digestible starch (SDS): SDS has a complex structure, meaning that the body breaks it down slowly. It exists in cereal grains.
- Resistant starch (RS): The body cannot easily digest RS, so it can pass through the digestive system largely intact, similar to dietary fiber. It may support healthy intestinal microflora. Experts further divide RS into the following categories:
- RS1, which exists in whole grains, seeds, and beans.
- RS2 from raw potatoes and unripe bananas.
- RS3 from foods that undergo cooking then cooling, such as rice and cornflakes.
- RS4, which is a type of chemically-modified starch.
- RS5, which have certain amylose-lipid complexes
Any given food type can contain various types of these starches.
Modified starch means that manufacturers have treated it to change its properties. The baking industry widely uses this form of starch because it can withstand a wide range of conditions, including extreme heat and cold.
Eating plenty of starchy foods as part of a balanced diet may provide energy and fiber, as well as increase feelings of fullness.
Energy
Starch is an important energy source for humans. The body digests starch by metabolizing it into glucose, which passes into the bloodstream and circulates throughout the body.
Glucose fuels virtually every cell, tissue, and organ in the body. If there is excess glucose, the liver stores it as glycogen.
Glucose is important for brain function, as it is the brain’s preferred fuel source.
Fiber
Dietary fiber is a
Although the body does not digest fiber, it is an essential part of a nutritious diet. Benefits of dietary fiber include:
- preventing constipation
- feeding gut bacteria
- slowing digestion
- softening stool
- promoting regular bowl movements
- supporting weight management
Fullness
Eating foods high in resistant starch may help increase satiety, which is the feeling of being full, after eating.
According to a 2023 review, current research offers inconsistent results about whether RS can significantly improve satiety.
Some evidence in the review suggests that RS may help to reduce appetite in adults with a moderate weight. However, more research is necessary to strengthen this conclusion.
For most individuals, starch poses no risks or side effects. Nutritional guidelines typically recommend a balanced diet that includes starchy foods.
However, people with certain health conditions, including diabetes and congenital sucrase-isomaltase deficiency (CSID), may need to moderate their starch intake.
The American Diabetes Association (ADA) recommends that people with diabetes who use insulin count how many grams of carbs they eat, then balance this with their insulin dose.
People with diabetes should avoid consuming large amounts of carbs in one sitting and instead spread them evenly throughout the day.
People with CSID will need to follow a special diet. People with this genetic condition cannot digest certain sugars and starches, so they will experience digestive problems if they eat certain fruits, juices, and grains. These issues can lead to malnutrition.
Starch is a carbohydrate and a natural component of most plants, including fruits, vegetables, and grains. Starchy foods provide energy and fiber, making them an important part of a balanced diet.
The body breaks down starch molecules into glucose, which is the body’s primary fuel source. The brain, in particular, uses a considerable amount of glucose each day.
Starchy foods are safe for most individuals and present no risks or side effects. However, it is important that people with diabetes or CSID carefully consider their starch intake.