TikTok Myth of the Week: Freezing Bread Makes It Healthier

According to TikTok, freezing bread makes it healthier. Various platform creators tell me that “something great happens when you freeze your bread,” that “diabetics should freeze their bread,” and even that freezing your bread makes it “keto-friendly.” There is some truth to this idea, but the people promoting it are missing some important caveats.

What do TikTok say?

According to several health-focused TikTokers:

• Freezing bread changes the starch structure in the bread (true).

• This, in turn, reduces the bread’s glycemic index by 31%, or 39% if you toast it (one study found this to be true for homemade bread, but not for store-bought bread).

• A lower glycemic index is thought to be better for people with diabetes (true, but not the whole picture).

• Thus, freezing bread reduces the risk of metabolic disorders (potentially true, but not really supported by existing literature) or prevents fat gain (not supported at all).

Each of the different TikTokers has their own point of view on why freezing bread is beneficial: some focus on blood sugar control for diabetes, some on weight loss, and so on. The guy claiming that freezing bread makes it “keto-friendly” made me laugh because it’s still bread, and it’s still mostly starch whether you freeze it or not.

What is resistant starch?

The main macronutrients in our diet are carbohydrates (carbohydrates), fats and proteins. The category of carbohydrates includes sugars, starches and fiber. Starch is the main component of foods you call carbohydrates. White bread, potatoes, and white rice, to name a few, are primarily composed of starch.

Starch is made up of chains of glucose, and glucose is sugar. When we eat, it breaks down quite quickly into glucose. But there is not just one type of starch: there are many. Some of these starches are called “resistant starches” because our bodies take a little longer to digest them. We cannot always break them down in the stomach or small intestine. Instead, we have to wait for bacteria in our colon to break them down and produce nutrients we can absorb. (This also possibly makes resistant starch a type of fiber and a prebiotic.)

So what does freezing have to do with it? Well, when starch is cooked in the presence of water, it changes shape and gelatinizes . Once cooled, it may become retrograde . This retrograde starch does not have the same structure as the original starch and is considered resistant to digestion (making it a type 3 resistant starch in particular).

Frozen bread isn’t the only product containing resistant starch. It can also be obtained by boiling and cooling rice or potatoes; many starchy foods also contain some resistant starch.

What is the glycemic index?

TikTokers often focus on the effects of resistant starch on blood sugar and point to studies that measure the glycemic index.

The glycemic index is a number scientists can give a food based on how much it raises people’s blood sugar levels when they eat a small portion of just that food . To be clear, this is not testing people who eat sandwiches, dinner, or breakfast. Instead, they eat (for example) 50 grams of bread, and their blood glucose measurements are compared to the blood glucose measurements when someone was given 50 grams of the reference material (either pure glucose, or sometimes they use white glucose). bread as a reference food product).

If you are interested in keeping your blood sugar levels more even, as many people with diabetes or other blood sugar problems are, you may want to avoid sudden spikes in your blood glucose levels. This is where knowing the glycemic index of different foods can help. For example, brown rice has a lower glycemic index than white rice.

Indeed, there is research showing that resistant starch can lower the glycemic index of a food, and there is also research showing that freezing bread can increase the level of resistant starch in bread. So what are TikTokers missing? It turns out there are a couple of important things.

This may not happen even with store-bought bread.

The biggest caveat to the advice on TikToks is that the study they all cite , which found that freezing bread reduced its glycemic index by 31%, only found that reduction in homemade bread.

The researchers also tested store-bought bread and found that freezing it did not significantly change its glycemic index. However, toasting reduced the glycemic index by about 18%.

These researchers speculate that the lack of effect in store-bought bread is due to dough conditioners and dough improvers, additives used in factory-made bread to help it mix better and prevent it from becoming stale. These supplements may prevent the formation of resistant starch as a side effect. However, they only tested one homemade recipe and one type of store-bought bread, so there may be other differences due to flour type or other factors.

The TikTokers promoting this hack do not specify that it is for homemade bread. Often they talk about freezing while pointing to a loaf of bread that looks store-bought.

The difference is still very small

Sometimes it is recommended to freeze bread to reduce its calorie content. If you can’t fully digest it, you get fewer calories, right? Technically this is true, but it’s unlikely to make much difference.

In this study , for example, resistant starch constituted 1.1% of the dry weight of fresh buns and 1.3 to 1.6% of the dry weight of frozen buns. In a typical slice of white bread, this equates to a 0.1 gram difference in carbohydrates. Carbohydrates are generally considered to contain 4 calories per gram. So you save less than one calorie if these numbers are representative.

There are better ways to manipulate the glycemic index

Remember how I mentioned above that the glycemic index is calculated in a laboratory setting and not based on actual food intake? If your goal is to lower your blood sugar, you might want to think about what you eat your bread with rather than whether the bread itself was frozen or not.

For example, here is an international table of glycemic index values . Relative to pure glucose, a French baguette has a glycemic index of 95. But a French baguette with chocolate spread has a glycemic index of 72. In other words, you can reduce the glycemic index of bread by 25% simply by adding chocolate spread!

I say this not to seriously argue that chocolate spread makes bread healthier, but to point out that lowering the glycemic index does not automatically make the food healthier or better for you. And if your goal is to lower the glycemic index of a food, then you can do this by adding other foods to it. For example, bread with butter is expected to cause a smaller increase in blood glucose levels than bread alone or bread with jam.

To look at this even more broadly, I’ve often said that when you’re comparing two very similar things (like which vegetables are the healthiest ), you should take a step back and ask if there’s more choice that’s worth paying for. attention to: Do ​​you eat this bread as part of a PB&J or a grilled chicken and veggie sandwich? That’s a much bigger difference than a few granules of resistant starch.

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