Calories matter, but we must also understand how those calories impact key elements of our biology, which I summarize as the CHE (Brain, Hormones and Stomach) in The Revolutionary Plan.

Focusing today on the Stomach, or more precisely, in the complete digestive system, we must understand the importance of maintaining a good microbiota. The bacteria in your digestive system weigh an average of 2 kilos and outnumber your own cells by a factor of 1 to 10. The collective genome of these bacteria is larger than your own. It is logical to think that your health directly influences your health.

Imbalances of this bacterial ecosystem are linked to obesity / inflammation (study), autoimmune disorders, depression (study), Alzheimer’s (study) and a long etc. Going further, recent studies suggest that this ecosystem is capable of modifying host behavior, and not in vain is it called the second brain.


Conclusion: If your microbiota is sick, you will be too.

Let us therefore remember the two main weapons we have to take care of our intestinal flora:

  • Probiotics: They are live bacteria, naturally present in food or added. We recommend that you include, for example, fermented foods in your diet or in specific cases even a supplement (especially if you take antibiotics). The problem is that many times this external contribution of bacteria does not have the desired effect, either because the bacteria die along the way (it is a dangerous journey until they reach their destination, the large intestine) or because the type of bacteria that are included he does not end up “getting along” with our existing population.
  • Prebiotics: They are indigestible substances that serve as food for the microbiota, with the aim of stimulating the favorable growth of our own native bacteria. That is, instead of adding external bacteria, we feed the ones we have.

Both are important, but today we will focus on the second aspect: feed our bacteria. In recent years, a special type of prebiotic has been arousing much interest, similar in some respects to traditional fiber, but with specific properties that make it especially interesting.

We talk about resistant starch. Today we delve into its benefits and how to incorporate it.

What is resistant starch?

When we think of starch we generally refer to the type that is easily convertible to glucose, ideal for example to replenish glycogen stores after a hard workout.

Resistant starch is different. As the name suggests, resists digestion. It travels through our relatively intact intestine, until it reaches the colon, where it is received, with open arms, by our bacteria.

There are actually several types of resistant starch (study):

  • Type 1: Indigestible starch as it is protected by plant cell walls. It is found in legumes, cereals, and seeds.
  • Type 2: It is inherently indigestible, due to its high amylose content. It is found for example in the potato (raw) and the green banana. If high temperatures are used when cooking it becomes digestible.
  • Type 3: Also called retrograde starch, since it is formed when certain types of starch are subsequently heated and cooled.
  • Type 4: It is a type of chemically modified artificial starch. It does not exist in nature.

This separation is not so clear in practice, and generally foods have different percentages of the first three types. Depending on how food is prepared or processed, the content of each type of starch varies.


We could say that resistant starch represents one of the healthiest foods for our bacteria. And if our bacteria are healthy, they will do a lot for us. Let’s do a quick review.

Improves metabolism

Resistant starch helps prevent metabolic damage in three ways:

  • Lowers post-meal blood glucose levels (study, study, study).
  • Improves insulin sensitivity (study, study, study).
  • Reduces low-grade inflammation (meta-analysis).

This does especially interesting for diabetics and people with insulin resistance.

Improves intestinal health


Resistant starch plays a relevant role in the following points:

  • Improves the integrity of the intestinal mucosa and the functioning of the immune system (study).
  • Reduces intestinal permeability (study).
  • It prevents certain endotoxins from crossing the intestinal barrier (study), surely the result of the two previous points (better protection of the intestinal barrier).
  • In animals it optimizes the absorption of minerals such as magnesium (study, study).

Helps to lose weight

You already know that hormones are the key when it comes to burning fat, so anything that improves insulin sensitivity and controls blood glucose will help.

But that is not all.

Resistant starch, being difficult to digest, contains half the calories of normal starch and increases satiety (study), making it a simple way to reduce caloric intake without starving (study, study). It also increases the oxidation of lipids, that is, we burn more fat for energy (study).

Although they do not have miraculous qualities as we see in some tabloid media, the scientific reviews are very promising (meta-analysis).

Produces good fats

We have talked many times about the wrong war on fats. All types of fat play a role in our health, and in fact our own bacteria contribute to the production of additional fat, such as butyrate and propionate (among others), with particular benefits.

Let’s start with the butyrate. Although there are foods with small amounts of butyrate (butter being the main source), it is negligible compared to what your bacteria produce from indigestible carbohydrates, and resistant starches are the most effective source (study).

Butyrate is the favorite energy source of the cells that form the walls of the colon (study), offering protection against colon cancer (study, study). Butyrate also contributes to several of the benefits we mentioned previously, such as intestinal integrity (study), reduced inflammation (study), and improved insulin sensitivity (study).

Although less is said about propionate, its production from resistant starch is also known (study), and recent studies relate it to greater satiety and less fat accumulation (study).


According to studies, the intake of resistant starches in “advanced” societies is about 5 g per day, well below the estimated 30-40 g per day that our ancestors ate.

As we saw, there are different types of resistant starches in foods. Ideally, include all of them, paying attention to the way of preparation to optimize their effect.

Some recommended sources resistant starch:

  1. Tubers (such as potato and cassava). Especially if they are eaten after cooling or reheated at not too high temperatures. Sweet potato provides very little resistant starch.
  2. Green banana or male banana.
  3. Vegetables (like lentils and peas).
  4. Some cereals, like rice and oatmeal.

An interesting possibility when experimenting is to use a supplement that isolates resistant starch. This allows better control of the amounts and analyze how we respond to each dose. This approach is especially helpful for those on a long-term ketogenic diet, as getting enough resistant starch from tubers and rice can excessively increase glucose consumption in some people.

Within the supplements there is a clear winner: starch or potato starch. It’s cheap, doesn’t raise blood glucose, and has 8 grams of resistant starch per tablespoon.

starch potato

Start with one tablespoon a day the first week and increase to two thereafter. If you don’t notice discomfort (like gas or bloating) you can go up to 3-4 tablespoons.

Another way to take advantage of the benefits of certain types of resistant starches is refrigerating and then reheating food, thanks to the retrogradation process. Recently an experiment was very popular in the media that “showed” that eating reheated pasta is less fattening. It sounds like the typical absurd headline, but in this case it is legitimate, and it makes sense if we understand the chemical change that occurs in starch when it is cooled and then reheated (without using high temperatures). And we can achieve the same effect with other starches such as tubers and rice.


In the coming years we will know much more about the hundreds of types of bacteria that inhabit our intestines and their effect on our health. But you don’t need to know all the details to start making profits now. There is sufficient scientific information and concrete success stories in humans as to start experimenting with confidence.