The Health Benefits of Leftover Rice, Pasta, and Other Carbs Explained by Resistant Starch

Is it beneficial to refrigerate rice before consumption?

The newest food trend on TikTok involves heightening the quantity of resistant starch in some foods by placing them in the refrigerator prior to eating.

This technique is based on the idea that allowing high-carb foods such as cooked potatoes, rice, or pasta to sit in the refrigerator or freezer for several hours or days permits them to form more resistant starch.

Resistant starch is so named due to its ability to withstand digestion in the human body.

Contrasting other carbs, resistant starch isn’t prone to actions of amylase, an enzyme found in the small intestine that fragments food into more minor components. Consequently, it ends up whole in the large intestine.

Once it reaches this point, resistant starch can only be disintegrated by particular healthy gut bacteria.

“Whole grains, legumes, and some seeds naturally contain resistant starch,” says Kim Kulp, an expert in gut health, RDN, and proprietor of Gut Health Connection in the San Francisco Bay Area.

TikTok influencers hint that an increased intake of this rare starch (which behaves like fiber) could yield health benefits like blood sugar stability, gut microbiome enhancement, and weight loss promotion.

“These microbes generate short-chain fatty acids, including butyrate, shown to safeguard the lining of the intestines while enhancing insulin sensitivity, influencing appetite hormones, and reducing abdominal fat,” says Kulp.

Supporters argue that uncomplicated food storage methods offer a near-effortless tactic to gain these effects.

Laura Purdy, MD, a board-certified family medicine practitioner, says, “What’s fascinating is that you don’t need to adjust your regular diet to incorporate more resistant starch, as this technique revolves around preparing and eating common foods.”

This trend is garnering attention with people trying it out for themselves. The #resistant starch hashtag currently boasts more than 1.7 million views on TikTok.

Here’s some vital information on how food storage practices could influence your nutrition and whether optimizing resistant starch in your diet is worthwhile.

To verify the veracity of TikTok's health assertions about resistant starch, each claim should be scrutinized individually.

But first and foremost, do these storage methodologies deliver as promised?

Based on Kulp, this TikTok trend withstands scientific validation for once.

“Cooking and cooling foods like pasta, potatoes, and rice, and freezing bread, do amplify the content of resistant starch in these foods,” she says.

Purdy concurs. “Once some starches go through heating or cooking and are subsequently cooled, they develop a new structure. This new structure might resist digestion, leading to additional health benefits,” she adds.

When it comes to specific health claims about foods rich in resistant starch, the evidence is not as clear-cut.

The most plausible claim is that refrigerated foods like cooked rice or pasta could help keep blood sugar levels stable. Kulp cites a 2023 study that found frozen bread slows the escalation in blood sugar, possibly lowering weight gain and type 2 diabetes risks.

However, other research fails to back up the claim that resistant starch contributes to weight loss.

A 2014 review concluded that even if resistant starch may enhance fat oxidation and lower fat storage, there's no direct data showing it impacts body weight, calorie consumption, or energy expenditure.

So, what's the deal with gut health?

It’s an established fact that the fermentation of resistant starch in the large intestine forms short-chain fatty acids (SCFAs) like butyrate. Research indicates that this specific SCFA reduces intestinal inflammation and adjusts intestinal motility (or to put it simply, assists in gut movement).

However, Kulp clarifies that not everyone will experience the same gut-level response to resistant starch.

“Just two species of gut microbes, Ruminococcus bromii and Bifidobacterium adolescentis, can convert resistant starch into the health-promoting compound butyrate. Given that different individuals have different microbiomes, not everyone benefits from resistant starch,” she explains.

Ultimately, refrigerating or freezing your favorite carbs probably won't hurt, and it might even yield minor health benefits.

According to Purdy, given that this trend is straightforward and low-risk, it could be worth trying. “If this method appeals to you and suits your lifestyle, then why not?”