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Health Hack #21 - Resistant Starch

The Potato Diet

Ever heard of it? Chances are you haven’t. The Potato Diet, also known as The Potato Hack, is a recently rediscovered weight loss hack which is just beginning to gain some new momentum. It was first written about in 1880’s, but went radio silent for more than a century. Its premise is equal parts simple and confusing. Eat potatoes. Lots of them. Limit your diet to nothing else, and focus exclusively on white potatoes, as opposed to the much more nutritious sweet potatoes. Make sure that your white potatoes have been cooked and then cooled prior to eating. The more that you can reheat and cool them, the more you’ll be able to eat without packing on any weight. You can consume pounds of white potatoes daily if you’d like, and potentially even lose pounds of body weight by doing so. What????

The mechanism at play relates to the manipulation of the starch within the white potato. Most of us are at least loosely familiar with the notion of starch. Mostly all grains are starchy, with breads and pastas quickly coming to mind. As far as vegetables, we associate starch with root varieties, like, well...potatoes. And then everything with a similar texture to potatoes, like squash, beets, yams, and carrots. On the fruit spectrum, bananas are most quickly associated with being starchy.

Starchy foods are generally heavier than non-starchy ones. Compare a starchy potato to an equivalent serving of non-starchy cauliflower, as an example. They’re more carbohydrate dense, and are much more likely to raise our blood sugar. In a balanced diet they’re necessary, but intended for consumption within moderation. Then why would this funky potato thing actually work as a weight loss strategy?

Resistant Starch

The key to the purported success of the potato hack isn’t the starch that we’re all familiar with. It’s what happens to this starch upon the cooking/cooling combination. During this process the starch within the potato coverts largely to a different form, one known as Resistant Starch.

Those devoted readers will recall a recent Health Hack that focused on Soluble Fiber. For those unfamiliar or interested in a refresher, click here. Though some references to former articles may seem superfluous, the Soluble Fiber piece is an extremely useful preface to the subject of Resistant Starch.

Like Soluble Fiber, Resistant Starch is not digestible. It travels beyond the small intestine (where our calorie-containing foods are digested), ultimately landing in our large intestine (a.k.a. colon, a.k.a. gut) where it begins to ferment. Here, again like Soluble Fiber, the Resistant Starch serves as prebiotic food for the healthy bacteria residing in our gut. It’s important to remember that the probiotics that can truly rescue our gut health are virtually worthless if they’re not being fed an appropriate diet. And the only valuable food sources for these beneficial bacteria are the prebiotics found in Soluble Fiber and Resistant Starch.

Resistant Starch is technically a fiber, hence its many similarities to the soluble kind. Its properties are unique and somewhat bizarre. It’s found mostly in the firmness of starchy foods. With white potatoes being the most interesting example, the process of cooking the potato reduces the amount of existing Resistant Starch. However, like almost all starchy foods, it must be cooked in order to become edible to humans. The key, here, is the later cooling of the food, where the Resistant Starch is restored after the food has been rendered edible via cooking. Eating a cooked then cooled white potato is literally far healthier than eating the same baked and never cooled potato fresh out of the oven. Crazy.

To wrap up this whole potato story, a noted perk of the diet is that one need not go hungry in order to lose weight. Since Resistant Starch is fiber and therefore non-caloric, you can keep yourself quite satiated eating potatoes only, while keeping your overall caloric intake fairly low. And the monotony of eating potatoes only is self-limiting. They get boring very quickly when they’re unadulterated, and so we’re less likely to overindulge. (It’s worth noting that we’re not by any means endorsing this type of hack diet. It’s devoid of the entire spectrum of micronutrients. It just happens to be helpful in shedding weight quickly and painlessly, and for that it holds relevance in conversation regarding best health practices and may pose a useful hack for those in need of shedding weight quickly. It also happens to serve as a nice introduction to Resistant Starch.)

What other foods contain Resistant Starch?

Green bananas function in a fairly opposite manner than white potatoes. They also require no cooking or manipulation to get the good stuff. As a banana ripens, it’s once Resistant Starch slowly transforms into simple sugars like fructose, glucose, and sucrose (to learn more on the spectrum of these simple sugars, refer to a former Health Hack here). Analogous to cooked/cooled potatoes versus merely cooked ones, green bananas are healthier than brown-spotted ripe ones. Another interesting tidbit, but one that probably comes more intuitively. Ripe bananas are nice and sweet, whereas green bananas are lacking in that pop of sugar. Unlike Soluble Fiber which can be found in sweet places like raspberries and blackberries, Resistant Starch doesn’t really pair with sweetness.

Green bananas stand pretty much all alone in the realm of raw, uncooked foods that are robust in this strain of fiber. The only other option is a green plantain, which isn’t nearly as ubiquitous as a banana, and doesn’t contain nearly as much Resistant Starch. Like the banana, you’ll want to be consuming the plantain well before it’s fully softened. Or better yet, seek out dehydrated plantains in the form of chips for a rich source of this special starch.

Resistant Starch is mostly found in whole grains and legumes that have been cooked. A short list of these foods with particularly high quantities is as follows, leaving out those foods already named above:

• Cooked Oats (Oatmeal is a great source)

• Cooked and Cooled Brown Rice (the rise in RS comes from the cooling)

• Beans (the Gods of Fiber, virtually all beans are loaded with quality sources)

• Lentils (which should be cooked, as should the Beans)

Incorporating any of these Resistant Starch rich foods into your daily diet will make for a more stable and happier gut.

Health Benefits of Resistant Starch


Like Soluble Fiber, Resistant Starch has an uncanny ability to invite fullness and reduce our appetites without the common tradeoff of consuming a ton of calories.


Our bodies become more efficient at utilizing insulin, allowing our blood sugar levels to quell more quickly following a surge of glucose consumption. In other words, by consuming more Resistant Starch, our bodies become more skilled at processing carbohydrates that we consume by learning to deal with the ensuing spike in our blood sugar more effectively.


As explained earlier, Resistant Starch will help stabilize the healthy bacteria that resides in our gut. In a diet devoid of Soluble Fiber and/or Resistant Starch, our probiotic bacteria will starve and die. When they do, real estate opportunities arise in our gut microbiomes, allowing pathogenic bacteria to take up residence. In time, our colon can be overwhelmed by these foreign invaders, leading to a host of dangerous ramifications such as depression, leaky gut syndrome, and irritable bowel syndrome. You may recall (How Realistic Goal Setting Positively Affects the Brain) that serotonin is best known as our Happy Hormone. Interestingly, 85% of our serotonin production arises from the gut. When we keep our guts as hospitable an environment as possible for our precious probiotics, we’re literally nurturing a breeding ground for our future happiness.