Just as I was shocked to learn that not all calories are created equal, I am surprised to learn that not all fibers have the same health benefits. Just as some calories tend to be stored as fat while others are burned, dietary fibers vary in the way they’re digested, which in turn leads to different physiological outcomes and health benefits.
A type of dietary fiber called resistant starch is digested in the large intestine and produces a feeling of fullness longer than fibers that are digested in the small intestine do. Because of this impact on our sense of satiety, foods containing resistant starch can be helpful in weight loss.
This conclusion is based on animal research and many human studies that found that consuming recommended amounts of resistant starch increased satiety, decreased hunger and resulted in lower calorie intake prior to the next meal and up to 24 hours after initial consumption.
Whether the large or small intestine gets involved, eating carbohydrates to lose weight–especially after their demonization by the Atkins diet and low-carb zealots–may seem too good to be true.
To understand this latest interest in resistant starch fiber, I turned to Hope Warshaw, RD, CDE, a nationally recognized dietitian and diabetes educator. Hope has over 30 years of experience as a consultant, an author and an educator, with a special emphasis on nutrition for people with diabetes. One of her books, Eat Out, Eat Right is in its third printing and has sold a half a million copies.
Here are my questions and Hope’s responses:
1. What’s the role of fiber and, more specifically, resistant starch fiber in a balanced diet?
A consistent finding is that a high fiber intake that includes whole grains helps with disease prevention, including heart disease, some cancers and type 2 diabetes. One more study published February 14, 2011, in the Archives of Internal Medicine correlated high fiber intake with a lowered risk of death from cardiovascular, infectious and respiratory diseases—by 24 percent to 56 percent in men and by 34 percent to 59 percent in women. Over 388,000 adults, ages 50 to 71, participated in this National Institutes of Health—AARP Diet and Health Study. As you can see, fiber plays an important role in maintaining our health and wellness.
Unfortunately, as Americans have increased their consumption of processed and convenience foods, they’ve decreased their intake of dietary fibers and resistant starch. Individuals in developed countries such as the United States, where processed foods are prevalent, consume inadequate dietary fiber and resistant starch. A 2008 study showed that Americans consume approximately 5 grams of resistant starch per day. A recommended level of resistant starch is 15 to 20 grams per day. This amount can help people obtain the full physiological and health benefits of resistant starch.
2. What is resistant starch?
Most starches are digested and absorbed into the body through the small intestine, but some resist digestion and pass through to the large intestine where, through fermentation, they are digested. This type of starch is called resistant starch. The formal definition of resistant starch is the total amount of starch and the products of starch degradation that resist digestion in the small intestine of healthy people.
3. What are the health benefits of resistant starch?
A number of studies (250 peer-reviewed) conducted over the last 20 years demonstrates that consuming resistant starch as part of a healthy eating plan provides multiple benefits:
- Dietary fiber intake is increased.
- Satiety and a sense of fullness increases and may, therefore, help with weight control. Researchers report that subjects who consumed resistant starch reported feeling fuller and more satisfied 24 hours after eating than those who did not consume resistant starch.
- Energy fluctuations are minimized. Glycemic levels are more stable and insulin sensitivity increases, while insulin resistance decreases.
- Digestive health improves through an increase in beneficial bacteria and a suppression of harmful bacteria. The resistant starch functions as a prebiotic fiber. Hi-maize resistant starch promotes regularity with a mild laxative effect and restores normal intestinal function in individuals with diarrhea.
4. What foods contain resistant starch?
Resistant starch is found naturally in some foods, including legumes, some whole grains and fruit. See the list below:
I medium Banana, slightly green
Oats, rolled, (raw) 1/4 cup
White Beans (cooked) 1/2 cup
Lentils, 1/2 cup, cooked
Pizza, 1 slice
Yams, 1/2 cup, cooked
Chickpeas 1/2 cup, cooked
Peas, green, 1/2 cup, cooked
Barley, pearl, 1/2 cup, cooked
Rice, brown 1/2 cup, cooked
Kidney Beans, 1/2 cup, cooked
Pasta (hot or cooled, white or whole wheat), 1 cup, cooked
1.2 grams (average)
Rice, white 1/2 cup, cooked
Quinoa 1/2 cup, cooked
Potatoes 1/2 cup, cooked and mashed
1 cup, cooked
5. Besides eating foods that naturally contain resistant starch, how can I increase my intake?
Hi-maize resistant starch can be found in a growing group of commercial products, such as bread, pasta and snacks. For a list of products containing Hi-maize resistant starch, go here.
You can also purchase and use Hi-maize resistant starch as a separate ingredient. For instance, it can be added to foods like smoothies or oatmeal for an easy fiber boost. One tablespoon of Hi-maize delivers approximately five grams of dietary fiber.
King Arthur Flour (www.kingarthurflour.com) sells Hi-maize resistant starch (#4765) that can be substituted for up to one-quarter of the flour in a wide variety of recipes. King Arthur Flour also sells High Fiber Flour (#3511), a mixture of flour and Hi-maize that can be substituted for 100 percent of the regular flour in recipes; however, these King Arthur Flour products are not guaranteed gluten free. Celiac Specialties (www.celiacspecialties.com) sells Hi-maize resistant starch that is guaranteed to be gluten free.
6. How many calories are in a tablespoon of Hi-maize resistant starch?
One level tablespoon of Hi-maize resistant starch contains 10 calories.
7. Are there any negative side effects of consuming Hi-maize resistant starch?
Large amounts of resistant starch found naturally in foods and in the ingredient Hi-maize can be consumed (up to 45 grams per day) with no reported digestive side effects. Hi-maize resistant starch does not cause gas, bloating, abdominal discomfort or diarrhea, as some fibers are known to do.
8. Is Hi-maize resistant starch the magic bullet we’ve been searching for to help us lose weight?
No! Losing weight and, more importantly, keeping it off long term, requires a multipronged approach that includes healthy foods, portion control, a good bit of physical activity and plenty of restraint. But incorporating an increased amount of resistant starch into an otherwise healthy and lower-calorie eating plan, balanced with sufficient exercise, may well be one more boost to help individuals lose weight and keep it off.
I’ve already ordered a supply of Hi-maize resistant starch from the King Arthur Flour website so I can experiment with this product. My kitchen will become my laboratory, and I will be the subject. I’ll keep you posted on my research results.