Top Doc Calls Resistant Starch a 'Game Changer' — Here's How It Boosts Weight Loss

Often, when we have a lot of unwanted weight to lose, we can feel stuck by the seemingly impossible task at hand. It can feel like only a total lifestyle overhaul could ever cause the scale to budge. So we were encouraged when we started hearing about small, ingenious food hacks — backed by serious science — that are making it easier for women to shed excess weight. The approach deals with eating a super-healthy fiber called resistant starch. “These little tricks can make a huge change in women’s gut health, hormone health and also metabolism,” contends Harvard-trained Amy Shah, MD, double board-certified physician and nutritionist. Keep reading to learn how to use resistant starch for weight loss and to improve your total health.

What is resistant starch?

We’ve all heard about different types of dietary fiber such as soluble and insoluble fiber. But there’s a third, lesser-known form of fiber called resistant starch. This fiber literally delays or “resists” being digested. As a result, some of its calories — between 30% and 50% — aren’t absorbed.

Up until this point, most food experts have focused on resistant starch that exists in whole foods like greenish bananas, sweet potatoes and nuts. But now bio hackers are teaching people how to take a food and enhance the amount of resistant starch it contains. We’re talking simple DIY tricks like freezing bread overnight before eating it, reheating leftover rice from the fridge or making oatmeal the night before you consume it. It turns out these simple tricks can have a positive effect on metabolism.

The science behind resistant starch

Resistant starch can increase our ability to lose weight. How? When a cooked carb is rapidly cooled, its starches reorganize in a chemical process known as retrogradation. This turns the starch into a special form of good-for-you fiber called resistant starch. Think of it like a magic time-release carb. Best of all, resistant starch is often found in comfort-food carbs like the ones we often feel we have to avoid entirely if we’re trying to lose weight. But not anymore. This loophole may allow us to have our cake and eat it too.

Dr. Shah adds, “Resistant starch is something people don’t know enough about, and it can be a game changer for a woman’s nutrition.” She adds, “I wish more people knew about this switch.” It’s a great tool, especially considering how women suffer higher rates of diabetes and fat gain around the abdomen during midlife.

How eating resistant starch supports weight loss

But resistant starch does so much more for our body than just slash calories. Ivy League–educated chemist Rhonda Witwer has been working with resistant starch for 20 years, using her background in marketing functional foods. Witwer, who runs the educational site ResistantStarchResearch.com, says, “All the science I’m seeing says resistant starch is about metabolism!” Here, the many ways resistant starch revs our system for fat loss…

1. Resistant starch stabilizes blood sugar

One study on freezing bread before eating it found the hack improves the glycemic index of the food by up to 30%. The result: Blood-sugar sensitivity improves by 39%. This means the body can avoid blood-sugar spikes and the subsequent crashes (and cravings) that follow.

Experts have known for ages that eating low-glycemic-index foods speeds weight loss. But it’s empowering to hear there are easy methods women can use in their own home to dial down a food’s GI rating. That means delicious comfort carbs don’t have to be off the table.

Dr. Shah tested the freezer-to-toaster bread trick herself with sourdough and wheat. She also consulted friends who wore continuous glucose monitors to see the data on how eating frozen bread affected their blood-sugar levels. The verdict: The freezer trick really works at minimizing blood-sugar spikes! (Click through to learn the Glucose Goddess's four hacks for weight loss.)

2. Resistant starch supports gut microbiome

More than anything else, resistant starch allows our healthiest gut bugs to thrive. When carbs break down and ferment to create resistant starch, they produce short-chain fatty acids such as butyrate, also found in butter and ghee. This compound is known to nourish intestinal microbes, snuff out inflammation and drive every aspect of our metabolism.

For this reason, resistant starch has been described as “fertilizer” for the gut and a “weight-loss wonder food” by scientists. One team of experts summed it up this way: Resistant starch helps us reshape our body “by reshaping the gut microbiota.”

Dr. Shah adds, “Resistant starch is just so beneficial to your gut bacteria. It is a way to cut the unhealthy carbs, blunt the blood-sugar impact and feed the gut, all in one.”

Related: Bone Broth Drinks Can Heal Your Gut to Boost Weight Loss

3. Resistant starch mimics Ozempic

Fiber naturally makes us feel full and satisfied, helping us cut down on mindless snacking. But resistant starch — found in foods like leftover potatoes and underripe bananas — also delays digestion and slows stomach emptying, similar to popular weight-loss prescription drugs like Ozempic. Indeed, animal studies have shown that ingesting resistant starch naturally increased the satiety hormone GLP-1 — the same one triggered by Ozempic — in the bloodstream for 20 hours. (Click through to read Ozempic: Miracle or Miss?)

Results: The resistant starch difference

Together, these three mechanisms help resistant starch foods transform the body. But what type of results are we talking about? Recent research out of China and in Nature Metabolism finds consuming resistant starch supplements with two meals daily resulted in major changes. Study participants­ lost 3% body fat (about 6.2 pounds), reduced their waist measurement by 4.4% and melted up to 20% of their belly fat in eight weeks.

Tim Steele, author of The Potato Hack, agrees, “Resistant Starch is a really big deal.” He goes so far as to say, “Potatoes are the best diet pill ever invented.” (Learn more about the potato diet.)

Dr. Shah, author of I’m So Effing Hungry, routinely sees patients drop 10 pounds in three months by eating more resistant starch. One woman we spoke with, Patty Harding, lost 100 pounds by adopting a plant-based diet with lots of resistant starch from potatoes and oats.

Resistant starch's health benefits beyond weight loss

The benefits don’t end with weight. Witwer says, “Weight is the tip of the iceberg with resistant starch. Metabolism is the mechanism, and it manifests in every aspect of the body.” Sure enough, resistant starch is being looked at for its potential ability to help reduce cancer, fight Alzheimer’s and reverse diabetes.

Witwer says, “It’s extraordinary. There are brilliant scientists all over the world, winning awards, studying every disease imaginable, demonstrating how important resistant starch is to health. I’ve never seen anything like it.”

Witwer knows firsthand. She was prediabetic until she started supplementing with resistant starch 20 years ago. Since then, she’s easily reduced her fasting glucose level from 110 mg/dL to a healthy, normal 90. And photographer Ann Overhulse, who lost 35 pounds with the help of eating cooked and cooled potatoes, also reversed prediabetes and got off heartburn meds.

Easy ways to get the perks of resistant starch

Interested in seeing what resistant starch can do for you and your health? Try these simple tips…

1. Eat more fiber

Most women are deficient in dietary fiber. We’re getting about 96% less than our ancestors due to the way fiber is removed from processed foods. Some experts even suggest that resistant starch offers the best science to date against processed foods. To correct the deficit, Dr. Shah recommends slowly working up to eating 30 grams of fiber daily from different forms, including resistant starch.

2. Reach for these resistant sources

You can find resistant starch naturally in foods like oats, beans, chickpeas, underripe (greenish) bananas and cashews. Or you can create it with clever food hacks like quickly cooling cooked rice, potatoes or pasta in the fridge overnight, then reheating them. And, of course, you can try the freezer trick with wheat or sourdough breads. Dr. Shah reminds, “It’s a special type of fiber we can easily get. You don’t have to buy anything special!"

3. Mind your carbs

While tweaking bread or rice improves the slimming potential of those foods, they can still cause sensitivity in some people. “The main strategy I use is placing beans at the top of the hierarchy of acceptable starches. They have more anti-cancer benefits, more plant protein, more slowly digestible starch, more resistant starch and lower glycemic load,” says Joel Fuhrman, MD, author of Eat to Live. Bread aside, he says, “More beans, nuts, seeds and vegetables. That’s where the money’s at.”

4. Quantity matters

Health and weight-loss benefits come from getting at least 15 grams of resistant starch daily. You can get there by eating foods like 1 cup of cooked oatmeal, which delivers just under 4 grams of resistant starch. Half a cup of cooked pinto beans gets you around 5 grams, while fava beans can earn you up to 12 grams. But high doses of this starch can be hard to get from food alone, and some studies tout supplementing with 30 or 40 grams daily. So some people opt for a concentrated resistant starch supplement, like Supergut shake powder or Jonny’s Good Nature Ultra High Resistant Starch Green Banana Flour.

5. Need extra help?

Many women struggling with menopausal symptoms may need more help than resistant starch can offer. That’s why Dr. Shah recommends starting the day with a meal that amplifies the benefit of resistant starch. She loves prebiotic herbs like cinnamon, cardamom and ginger. “These spices work synergistically with resistant starch in the gut.” In fact, she created Amy MD Chai Latte Mix. “Starting the day with resistant starch — like oats with bananas — and having the chai protein drink makes for a really healthy premenopausal breakfast.”

Upgrade your meals with these resistant starch swaps

Turn a carb into a slimming resistant starch superfood with these ultra-easy,
study-backed substitutions...

• Skip it: Ripe bananas. Pick it: Greenish bananas.

• Skip it: Fresh bread. Pick it: Frozen and toasted wheat or sourdough.

• Skip it: Straight-from-the-stove potatoes. Pick it: Reheated mashed potatoes.

• Skip it: Hot oatmeal. Pick it: Cooled overnight oatmeal

Resistant starch success story: Georgina Hughes

Georgina Hughes looked at her pill bottle and felt conflicted. She’d been taking meds for years to cope with an inflammatory disease that left her stiff and in pain. But she knew those pills, plus eating a Standard American Diet, had damaged her gut and led to her uncontrolled weight gain. Yet eating healthy-gut foods like fermented sauerkraut and kombucha didn’t seem to help. Discouraged, she reveals, “I’d been trying to get healthier for years, knowing that disease begins in the gut.”

Then Georgina stumbled upon Tim Steele, author of The Potato Hack. She says, “Tim’s blog was the first I had heard of resistant starch.” Georgina put his nutrition advice to work. She ate mostly cooked and cooled potatoes for up to four days a week, and tried to eat healthy the rest of the time.

Georgina lost 3 pounds every week with that trick

Georgina recalls, “I quickly felt 10 to 15 years younger!” She also noticed she began to sleep better. Her gut health improved and her cholesterol dropped from 214 to 191. She even avoided a hip-replacement surgery. And talk about a health success story: Georgina shares, “Eating resistant starch contributed to my inflammatory disease going into remission!”

For more on the benefits of resistant starch, click through:

Eating More of This Starch Can Boost Gut Health and Aid Digestion

Chickpea Cookie Dough Is the Viral Dessert Helping Women Lose Weight Deliciously

Don’t Throw That Leftover Rice Out: Fry It Up Into a Delicious, Unusually Healthy Side Dish