Sugar Alcohols Making You Fat

author avatar Dr. Eric Berg 08/31/2023

Recently, on my show, a lady called in and asked why she gained four pounds of weight after eating a keto meal she’d made. She expected to lose weight, even though her meal included chocolate chip cookies for dessert. She used alternative sweeteners instead of table sugar as an ingredient in the cookies; the sugar alcohols such as xylitol and erythritol. Yet still, she experienced four pounds of weight gain instead of weight loss.

And she was baffled.

a photo of a woman holding her bloated belly

In this article, I’ll explain:

Let’s take a look at what was going on with the woman who gained weight after her keto meal.


What Sugar Alcohols Are

Sugar alcohols are compounds derived from sugar, but they don’t provoke the same response in your body that sugar does. They don’t spike your Fat Storing Hormone. They also have fewer calories. Sugar has 4 calories per gram, whereas sugar alcohols have anywhere from 1.3 to potentially 3 calories per gram, depending on the type.

There are numerous sugar alcohols. Xylitol is the most well-known of all the types of sugar alcohols. Erythritol is also common. If you’ve ever chewed sugar-free gum, you’ve probably consumed a sugar alcohol.


You Might Experience These Three Unpleasant Side Effects

Some people do just fine when consuming sugar alcohols, but many people experience three very common side effects. They are:

  1. Bloating
  2. Gas
  3. Diarrhea

These side effects occur when you consume excessive amounts - more than about 25 grams. Yet some people are very sensitive to sugar alcohols, and as little as ten grams gives them diarrhea.

A key difference between sugar and sugar alcohol is that sugar is completely absorbed in your small intestine. Sugar alcohols don’t get absorbed there. Instead, they move to your large intestine, to be consumed by microbes.

a word cloud for gut microbes

Think about the implications of this for a minute.

The sugar alcohol must move through 23 feet of small intestine before it gets to your large intestine. It takes time for it to move through that distance. Then, when it reaches your large intestine and microbes go to work, one or more of those three side effects occurs if you consume too much.

In other words, the sugar alcohol moves very slowly through your system undigested and unabsorbed, until it arrives in your large intestine which is where it ferments because of the microbes feasting on it. The fermentation produces gas, similar to what occurs in the fermentation process by which foods such as yogurt and sauerkraut are made.

The thing is, fermentation can also promote water retention.

Why You Gain Weight After Eating Sugar Alcohol

Water retention is the clue as to why you gain weight when you eat sugar alcohol. When you gain weight, it’s water weight not fat.

Unfortunately, you may be one of the unlucky people who can’t consume sugar alcohols without a reaction. If you find you gain weight every time you eat sugar alcohols, then you’ll need to avoid them. I know, it’s a downer. Sugar alcohol can help ease a sugar craving.

You can certainly test first to see if your body reacts when you eat them. Perhaps you’ll be one of the fortunate people who don’t gain water weight. If so, good!

The main point I want to make is you don’t gain fat when your weight increases after you consume sugar alcohol; you’re retaining fluid. This is a completely different situation from gaining body fat. In this case, the remedy is simple: stop eating sugar alcohol.


The Right Time To Consume Sugar Alcohol

Another point: all the desserts that contain sugar alcohol are really meant to be eaten in the transition period when you’re first coming off of sugar in your diet. There will be a point when you don’t need them anymore, because you don’t have any more cravings.

In other words, using sugar alcohol is really a temporary situation, usually when you’re transitioning to the Healthy KetoTM diet. They’re not meant to replace sugar over the long term.

And isn’t that good news? Not only is it easy to stop the water weight gain if your body reacts to sugar alcohol, but after awhile you won’t even want to eat them because your craving for sweets will be gone.

a group of healthy people

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Disclaimer: Our educational content is not meant or intended for medical advice or treatment.

Editor’s Note: This post has been updated for quality and relevancy.

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