Research in RS is relatively new. It appears the more resistant starches content there is in a food, the fewer usable calories it will have. Since RS is incompletely digested, 100 grams of resistant starch is (estimated) worth 200 calories, while 100 grams of other starch gives us 400 calories. All based on nascent research.

https://www.prebiotin.com/prebiotin-academy/what-are-prebiotics/dietary-fiber/ classifies RS as a subtype of fiber.

https://fiberfacts.org/fibers-count-calories-carbohydrates/  and https://www.verywellfit.com/why-are-there-calories-in-soluble-fiber-2242320 and https://www.bodybuilding.com/fun/ask-the-macro-manager-does-fiber-count-in-calories.html basically equate RS to fiber.

For reference, “insoluble fiber” is supposed to be calorie-free since it is never broken down never digested. Resistant starch appears to have the same effect as fiber i.e. Adding resistant starch to meals increases feelings of fullness and makes people eat fewer calories

Many calorie counters argue that fiber (+RS) should be subtracted from total carbs when calculating and labeling calories. https://www.bodybuilding.com/fun/ask-the-macro-manager-does-fiber-count-in-calories.html says “If there is any caloric difference due to fiber, it’s small enough”. I agree that calorie calculation is inherently imprecise in many ways.

Here are a few foods rich in resistant starch but mostly starchy. Among them, my top choice is green banana followed by green peas.

• 1) cooked then cooled potatoes, then eaten cold
• 3) cooked then cooled white rice.
  • Brown rice offers same amount of resistant starch but offers more fiber.
• 2) green banana — its resistant starch slowly becomes regular starch when it ripens.