Health Scientist Says People Should Be Aware Of The Risks Of 'Rice-Zempic,' TikTok's Latest Weight Loss Fad
A health scientist's reality check of a Tik-Tok craze.
esolla, Layer-Lab | Canva Rice-zempic is a new TikTok trend claiming rice water is as effective as the drug Ozempic for losing weight.
Its protagonists prepare it by soaking unwashed rice in warm water for 30 minutes, adding lime juice, and straining the rice before drinking the water.
“It’s not magic. It’s science,” explains TikToker Jessica Chasteen whose video has attracted 2.3 million views and 167,000 likes (at the time of writing).
Here is a quick sniff test of the Rice-zempic logic:
- Rice contains digestion-resistant starch (correct)
- Resistant starch promotes weight loss (partly correct)
- Soaking rice in water + citric acid extracts that starch (partly correct)
- Ergo, drinking the water will reduce your weight (not so fast)
Before you rush off to follow Dr. TikTok’s prescription, let’s do a little reality check on those claims.
I’ll also point you to some more science-grounded variations of the ‘Rice-zempic’ idea, which you might try if Dr. TikTok’s prescription disappoints you.
Starch is the plant kingdom’s way of storing carbohydrates. It’s the equivalent of glycogen in humans. Starch is a brilliant evolutionary way of packing more energy (glucose molecules) into a tighter space. Starch comes in two shapes, amylose and amylopectin. Their building blocks are the same — simple glucose molecules.
It’s how these molecules are welded together into those tight structures that determine whether our digestive juices can break them apart and send the glucose into our bloodstream (amylopectin) or not (amylose).
That’s why amylose is called “resistant starch” (RS) and amylopectin “digestible starch” (DS).
To make matters a little bit more interesting, there are four categories of resistant starch which we need to keep in mind to understand its potential as a weight loss “drug”.
The four major categories of RS: RS1 is inaccessible to digestive enzymes because it’s physically trapped within the food matrix. That doesn’t mean RS1 is all amylose. RS1 can be any type of starch, even a digestible one, but digestion isn’t going to happen, because the digestive enzyme, amylase, can’t penetrate the protective layer around it.
RS2 is the real-deal amylose. It’s inaccessible to amylase due to its structural conformation.
RS3 is the ‘Cinderella starch’. I call it so because it morphs from DS to RS, from fattening to weight reducing, once you cook your rice AND refrigerate it. What happens in the fridge is that some of the starch turns into an amylose configuration, so that your rice contains more RS after cooling than when you take it off the stove. The scientific term is retrograded starch, and it works not only on rice but on pasta, too.
Then there is RS4 which doesn’t interest us here because these are starches that have been chemically modified to be resistant to digestion.
Dissecting the Rice-zempic weight loss claims:
Claim 1: Rice contains resistant starch
Yes, so does almost every plant that humans eat. And rice isn’t exactly the star among them. One type of rice, sticky rice, is almost devoid of RS. Rice has a starch content of approximately 70–80% according to the USDA, only 1.2% -1.7% of which is RS. How TikTok’s cheerleaders of weight loss got fixated on rice as the source of RS is, shall we say, intriguing.
Though the notion that RS might be a small-caliber alternative for Ozempic has some credentials. So, let’s look at those.
Claim 2: Resistant starch promotes weight loss
There are two pathways through which RS may affect body weight. One of the two is obvious: The larger the proportion of RS in our food the lower its energy yield and the happier we will be when we step on the bathroom scale. The second pathway isn’t so obvious. It’s the one that lends credit to the Ozempic comparison.
Here is a brief on how Ozempic works its magic.
Ozempic’s molecule, Semaglutide, is a so-called GLP-1 (glucagon-like peptide-1) receptor agonist.
GLP-1 is a hormone released by the gut once food has made its way there (the ileum portion of the small intestine if you need to know).
Once released, the hormone activates cells of the pancreas and the brain that are dotted with GLP-1 receptors. They orchestrate a systemic response to slow down the emptying of the intestinal tract (makes you feel fuller longer), amp up insulin production, lower blood glucose, and, most importantly, curb the desire to eat.
That effect however dies down fast. That’s where Ozempic comes in. It keeps the GLP-1 receptors continuously engaged, which is an ingenious weight-loss strategy: mimicking the post-meal hormonal environment in which you have no desire to eat.
RS engages this GLP-1 magic more naturally. Since the small intestine is incapable of digesting RS, it ends up in the colon where specific bacteria start fermenting it. One of the fermentation products is a short-chain fatty acid called butyrate, or butyric acid.
The evidence supports the idea that a habitually RS-enriched diet may lead to sustainable weight loss and protection against diabetes.
First, regular RS intake is useful to “dial in” a specifically healthy microbiome composition that amps up the production of butyrate.
Second, increased butyrate production promotes a sustained increase in circulating GLP-1.
Third, GLP-1 increases satiety and reduces food intake, as we know from the Ozempic success.
And, fourth, RS intake has been shown in a 2024 human trial to reduce body weight.
So, yes, the TikTokers have the evidence on their side concerning RS. But how on earth did they dream up the rice-water-cum-citric-acid fad?
Claim 3: Soaking rice in water + citric acid extracts starch
Soaking rice in hot water will extract starch, and part of it is RS. Let’s have a look at the magnitude of extraction.
Soaking rice in water heated to >50 degrees Celsius for 60 minutes extracts somewhere between 20–35 mg starch/g rice. That depends, of course, on the type of rice and its overall starch content. Approximately 15–17% of the eluted starch is RS. Translate that to soaking 100 grams of rice in water, and what you get is at best: 3.5 g starch, of which 0.6 g are RS.
Now add the citric acid and your yield of RS will increase. By how much, we don’t know exactly, because, to my knowledge, the increase has not yet been experimentally quantified. But in cooked rice, that had been soaked in ascorbic acid-enriched water (40mg/ml) the yield of RS can be almost tripled.
So, let’s be charitable and apply this tripling rate to our best-case scenario. You’ll get at the very best 1.8 g of RS. That doesn’t sound like much.
Claim 4: drinking the rice water will reduce your weight
Our fact-check doesn’t convince me. If it was that simple to reduce body weight and prevent or reverse obesity and diabetes, don’t you think we would have known by now? Long before the pharma industry invested billions of dollars into developing a drug like Ozempic?
TikTok seems to be a land whose inhabitants mostly score low on science and common sense but off the charts in confidence. At least in Rice-zempic territory.
However, I am convinced that RS can indeed be a valuable weight loss aide. Maybe even using rice as its source. But only if we tweak the preparation method. So, let’s look at how to do that.
The idea of engaging the GLP-1 pathway by dialing up the RS content in our food has its appeal. Using the rice water method seems inefficient, though. It also wastes the other nutrients contained in rice, proteins predominantly.
Turbo-charging the rice-zempic method
Remember what I said about the Cinderella RS? Let’s use rice to produce it. Here is how:
Method 1, conventional rice cooker:
Soak 100 g of rice (ideally brown rice, or long-corn white rice) in 130 ml of water for 30 minutes before cooking. Pour rice and water into your rice cooker, add ascorbic acid, and let the cooker do its thing. Keep the cooked rice overnight in the refrigerator.
Eat the rice the next day as a meal by itself or as a snack (in the morning or latest by lunchtime). You can reheat the rice, but you’ll lose some, not all, of the retrograded RS.
Method 2, use a pressure cooker:
Prepare the rice in the same way as Method 1, but cook it in a pressure cooker for 30 minutes. The standard pressure in such cookers is 15 psi and a temperature of 120 degrees centigrade (250 degrees Fahrenheit).
The advantage of this method is a maximization of RS yield that can’t be topped by subsequent refrigeration. That’s why you can consume the rice directly after cooking. The reference tells you that this is not an invention of mine. It’s one of those few recipes for which there exists a lab study. Which should give you an inkling that researchers are serious about RS.
The Supplement alternative
Lucas Guimarães Bueno | Pexels
I’m not advocating it, but if rice is not your thing, there are RS supplements on the market. I did a quick search on Amazon and found an RS supplement called “supergut” which claims to be “The gut-healthy GLP-1 booster”. Its daily one-time serving is 6 grams. But it’s costly.
I refrain from including the link to this product, so that you know I’m not advertising it. I simply relate what I found on the web. Of course, there are non-supplement alternatives. Potatoes come to mind, because of their high RS content and the fact that they are ideal for retrograding RS by keeping them refrigerated after cooking.
I plan to give the plain rice of method 1 a try. I have no pressure cooker, but I have a rice cooker. My love affair with rice began the day when I first came to Singapore, more than 40 years ago (I have spent almost 2 decades there and in other SE Asian countries).
Fried rice is my absolute favorite, but I’ll try plain cooked and refrigerated rice as a between-meals supplement. I’ll monitor my weight and will report the result of my experiment.
Lutz E. Kraushaar is a longevity researcher on a mission to rewrite the aging playbook as an author, speaker, and consultant. His qualifications to do so include a doctorate in Public Health Sciences and an MSc. in Exrx & Nutrition.