Why Tim Ferriss Avoids Sweeteners of Any Kind

tim ferriss on sweeteners

A cautionary tale for Stevia junkies...

Tim Ferriss begins Episode #324 with his usual spiel.

He’s featuring Four Sigmatic. The mushroom tea guys.

They want him to promote Reishi Tea, an ancient Chinese sleep-aid.

He says lose the sweeteners, and I’m in:

“Their old formula included Stevia and I like to avoid sweeteners – all sweeteners – for a host of reasons. So I said hey guys I would love to experiment with this and maybe actually suggest it, but I’d like a version without sweeteners.”

And so Four Sigmatic creates an unsweetened version just for Tim.

But then they have Tim read a boilerplate warning that Reishi is bitter – and you should have it with honey or sweet nut milk.

Which sends Tim off-script...

“I”m gonna say NO. You should suck it up and you should drink the tea because it’s not that bitter.

“So no don't put in honey or nut milk or any of that shit just drink the goddamn tea. It’s delicious. I think.”

Wow tell us how you really feel Tim!

But why does Tim avoid sweeteners?

tim ferriss avoids sweeteners

They have no calories. They don’t affect blood sugar. They’re like a free pass, right?

Well what if they weren’t.

What if these sweeteners affect your brain just like plain ol' sugar does?

What if eating anything sweet makes you crave the real thing even more?

Well the research is in. And it turns out Tim Ferriss might be onto something.

Science has much to caution about the use of sweeteners – both natural and artificial alike.

And you might want to think twice before adding a few drops of Stevia to your next batch of fat bombs...

The straight dope on sweeteners

keto sweeteners

Since Saccharin was first discovered in 1879, calorie-free sweeteners have come with a big promise: to help solve our obesity crisis.

Well 130 years later, we have 6 FDA-approved sweeteners but obesity is the worst it’s ever been. What gives?

This question got scientists curious. And they found something ironic…

That sweeteners might be worse for us than sugar!

It happens in 3 ways:

1) Sweeteners activate the same food reward pathways as sugar

keto sweeteners brain

Your body has two systems to regulate food intake.

System #1 monitors your food’s calories – the so-called postingestive system. It ensures you get enough energy from your food.

But that’s not all. Your body also seeks reward from food.

Brain chemicals reward you when you eat. They tell your body you’ve “done good” by eating. Dopamine releases. You feel pleasure.

Pleasure motivates you to keep eating and you stay alive (ingenious, eh?).

But... what happens when we activate the reward system – with sweetness – but don’t give your body energy? Does the whole system get screwed up?

A few clever scientists set up an experiment to find out.

In their study, they fed fruit flies a diet of artificial sweeteners (sucralose) and compared their food intake against a control on a pure sucrose (sugar) diet. And… they found the group on artificial sweeteners consumed more calories after sweetener use.

Lead researcher Greg Neely summed it up:

“When sweetness vs energy consumption is out of balance for a period of time, the brain recalibrates and increases calories consumed.”


The take away from al this? We seek food to satisfy an inherent craving for sweetness. When sweeteners give us incomplete satisfaction (sensory and caloric), we eat more to compensate.

Maybe that’s why a tray of keto fat bombs has a nasty habit of vanishing….

2) Sweeteners can cause harmful changes in gut bacteria

keto sweeteners gut bacteria

New research has found a sneaky way sweeteners could be messing with your system…

Your gut.

You have right now trillions of bacteria living inside of you. They promote everything from healthy digestion to blood sugar control.

In a cleverly designed study, Israeli researchers fed mice either sugar or one of three sweeteners: aspartame, sucralose, or saccharin.

The sugar-fed mice stayed healthy after 11 weeks.

But the artificial sweetener-fed mice all developed abnormally high blood glucose. And through fecal transplants, researchers proved their microbiome was to blame.

They found sweeteners favored populations of “bad” gut bacteria (Firmicutes). This bacteria pulled energy from the mice's food and stored it as fat. And left the mice seriously glucose intolerant!

Results were so compelling, researchers repeated the experiment with a small group of humans. And after 5 days of the FDA’s maximum dose of saccharin… 60% developed glucose intolerance.

Could sweeteners be spoiling your healthy metabolic changes on keto? Research suggests it might.

3) Eating sweet things might make you like sweet things

keto sweeteners

Here’s an interesting question: if you eat something over-and-over, will your taste for it change?

To find out, researchers put subjects on a low-sodium diet for 5 months. They found salty foods became more intense for experimental group. Their “maximum pleasant” sodium levels were far lower than the control.

The mere exposure to salt changed their taste for it.

Researchers found the same thing with fat preference on a reduced-fat diet.

Think when you find a catchy tune. You rock out and play it over-and-over. But after a thousand plays... you can’t stand it.

How does this apply to sweetness? Eat more sweet foods, and you’ll need higher levels of sweet to satisfy your cravings. It’s a vicious cycle that could leave you craving the real thing.

But limit the sweeteners, and you’ll need less stimulation. Could a 100% cacao bar eventually taste like a Snickers?

It’s gotten close for us.

Bottom Line

Now you may say… “okay but all this research has been on unnatural sweeteners like sucralose and not the good keto sweeteners like monk fruit!”

And that’s true. The data doesn’t prove all non-sugar sweeteners are bad for us.

But... our experience shows excessive use of sweeteners always has a hidden cost – even if you never kick of out of ketosis.

Whether by inducing sugar cravings or changing how you taste sweet, sweeteners can spoil your progress in ways that aren’t always obvious.

That’s why you’ll never find sweeteners added to our products.

Maybe we’ll steal a line from Tim and say:

“So no don’t add monk fruit or stevia or any of that shit. Just eat the goddamn chocolate. It’s delicious. We think.”

Okay, well maybe with a touch of almond butter.

To your health, 

Ben & Brandon

Disclaimer: This website provides general information and discussions about health, nutrition and related subjects. The information and other content provided in this blog, or in any linked materials, are not intended and should not be construed as medical advice, nor is the information a substitute for professional medical expertise or treatment. If you or any other person has a medical concern, you should consult with your health care provider or seek other professional medical treatment. Ben & Brandon are not doctors, registered dieticians or registered nutritionists.

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