As the pros and cons of carbohydrates continue to be debated in the popular press, a new twist has emerged. Resistant starch is a type of carbohydrate said to accelerate weight loss. Weight-loss coach Andrew Cate shows you how it works, and how to get more in your diet.
What is resistant starch?
Most fibres and starches are digested and absorbed into your body through the small intestine. Resistant starch is a unique type of fibre found in some carbohydrate foods that your body finds hard to digest. Because it "resists" digestion, it arrives whole in your large intestine. Once there, bacteria ferment it, producing fatty acids that are absorbed into your bloodstream it's these unique fatty acids that have some interesting weight-loss properties.
How does resistant starch help you lose weight?
A study published in the journal Nutrition & Metabolism in 2004 showed resistant starch can increase fat oxidation significantly, helping to change the way the body burns fat as fuel.
One specific fatty acid produced from resistant starch fermentation called butyrate is thought to block the body's ability to burn carbohydrates. Usually carbohydrates are used first for fuel, but when butyrate is present, stored body fat and recently consumed dietary fat are used earlier as an energy source.
Researchers found that replacing just 5.4 percent of carbohydrates with resistant starch increased fat burning (the use of fat as fuel instead of carbohydrates) by 23 percent. Resistant starch in a meal is associated with less fat storage after that meal, and over the long term, that could help to significantly reduce the storage of body fat.
An earlier study, published in the Journal of the American College of Nutrition in 1996, showed that when normal flour is replaced with a flour alternative that is high in resistant starch, the kilojoule content of that food is reduced. This is another way that resistant starch can contribute to weight management and weight loss.
Are there any extra health benefits?
In addition to weight control, resistant starch is thought to provide other health benefits, including:
- improved diabetes management;
- improved bowel health;
- reduced blood cholesterol levels;
- reduced blood triglyceride levels; and
- increased satiety (fullness) from food.
What foods are high in resistant starch?
There are actually several varieties of resistant starch, although they all have a very similar function. One of the best sources of resistant starch is called Hi-Maize, which comes from a special breed of corn. It's used as a food additive in breads, pasta and breakfast cereals without altering the taste, colour or texture of the food. You can also buy it at health food shops and use it instead of flour. Other sources of resistant starch include:
- intact wholegrain cereals, seeds and nuts, such as oats, rye, wheat, barley, semolina, corn, linseed, sesame;
- legumes such as lentils and baked beans are a very good source of resistant starch;
- unripe fruit, especially bananas; and
- cooking and cooling carbohydrate foods can also increase their resistant starch content, such as cold rice (sushi), cold pasta salad and potato salad.