No.

^^^ Answer to title question.

Here's an article I wrote that details why. TLDR: your pancreas functions differently during exercise than any other time.

That said.... if you eat a ridiculously low amount of protein all day, yes, your diet overall can cause diabetes.

If you eat a diet that is almost exclusively highly-processed carbs outside of training, contains little to no fiber, almost no protein, yes indeed you can make yourself prediabetic.

My wife and I tested this - on ourselves, of course.
(Context: She's a pro triathlete and sport scientist who also happens to be a board certified specialist in sport dietetics.)

We asked:
"Where is the tipping point? How low does protein intake have to be while doing high carb, to cause blood sugar dysregulation?"


Answer: Less than 40 total grams of protein per day for her. I quit before I got there.

We started at 100g and stepped it downwards by 10g daily protein intake, every 3-4 weeks. This was with 350-750g of carbs per day. It's an utterly ridiculous approach to nutrition.

This approach gets really hard to follow hard to follow without developing disordered eating tendencies because when you're chowing 700g of carbs per day, you have to selectively choose low-protein carb sources and intentionally not eat ANY protein all day, just to keep your trace protein from adding up to 40g/day. It means saying 'no' to wheat bread and opting for white rice with teriyaki sauce on it because there's too much protein in the bread. (When we were experimenting with a max of 40g protein per day). Anecdote: The cravings a diet like this will cause are unreal.

Warning: may crave a dry hunk of baked lean chicken breast.

At this point we started noticing the very first drift upwards of fasting blood sugar. Nothing even considered pre-diabetic, technically, but high enough that even our extreme-let's-test-the-limits approach to our personal decisions was put on the shelf. We canned the experiment because we were already below what we know is adequate protein intake for a human in general. :)

I wonder what Lachlan's diet was like. Let me check his prior video on that and see what he eats...

• 8 slices toast + bun + biscoff + butter → 13g protein
• Soy milk + sugar cereal → 8g protein
• Orange juice → 0g protein
• Banana → 0g protein
• Lots of Instant Noodles → 5-8g protein
• Corn Flakes → 2g protein
• 2 chicken wings → 15g protein (I'm being generous by the looks of it)
• Sweet potatoes → 1g protein

Total protein estimate → 45-50g, almost exclusively from trace sources. And an absurd amount of high glycemic index carbs outside of training. Where is the fiber and nutrient density!?

This is indeed a recipe for diabetes.

Folks, please eat 0.5-1.0g protein per pound of body weight per day. Type 2 diabetes risk will be near zero if you exercise and have healthy body composition. Aim on the upper end if you've ever struggled with obesity or blood sugar dysregulation. It's that simple!

Here's a more thoughtful take on protein for endurance athletes. It's 8 minutes. It'll tell you everything you need to know about how not to become diabetic while consuming a diet that fuels you best.

Or you can purchase SFuels and fix your self-induced diabetes here. WARNING: their marketing department is bigger than ours. The rabbit hole is deep as Lachlan found (and Sam Long, IIRC). My advisement is to steer clear. Lachlans links to Dan Plews, Andrew Koutnik, and Peter Brukner made me chuckle. SFuels is the video sponsor. Lachlan is also personally sponsored by SFuels, by the sound of it. As I mentioned on a thread in reddit, that says it all.

Disclosure: Our app recommends sugar as fuel. If you're concerned about blood sugar issues, just set the "satiety management" setting towards "whole foods" and you're good to go. That setting allows you to scales carbs WAY back on easy days. Kind of like the "right fuel right time" approach, just without the dogma. Sorry, Dan, it's Saturday, and I'm feeling feisty. Dan, I'd love to meet and chat with you someday. I suspect we think more alike than different. YouTube collab?? :)

Lachlan if you happen to read slowtwitch, another option for fixing your diet would be to double your daily protein intake to about 80-120g/day, triple your fiber intake by eating veggies and legumes a bit more often. Nothing stringent, and nothing "all or nothing" mindset. Triathletes (especially those working in finance) tend to sometimes get really black and white about their approaches to things. Keep your diet fun and liberalized and do some of the basics and your blood sugar will be fixed. You can get pre-cooked frozen chicken, and frozen veggies an throw them in the microwave a couple times a day, and you'll be most of the way solved here. One other tidbit might be to target consuming a few more complex carbs outside of training and making mostly just the fuel during training the sugar you consume. Sugar post-training is great. Sugar around the clock isn't helping things. All that said, chat with your MD (or RD, CSSD!).