Insulin sensitivity and long-distance travel

I've found that any time I travel to a time zone that's dramatically different from home (10+ hours) my basal requirements drop nearly 50% within 24hrs of arriving. All other variables remain the same - diet, exercise, etc, as well as my bolus requirements. This happens every time I travel to Asia and my basal rates return to their previous levels within 24 hrs of returning home.

Has anyone else experienced this or know why this is? None of my Dr's are able to explain this.

This happens to me when I travel to Japan for work (I think about 40% basal reduction), but in my case I would dispute that my diet and exercise remain the same. As far as exercise, I am just much more active in Japan. At home I drive to my parking lot and walk in the door; same at night; the only real exercise I get is when I go to the gym. In Japan I walk to and from the train station, stand in the train, walk to restaurants for lunch and dinner, walk to see sights in my time off, etc.

I am also eating a Japanese diet, which is higher in carb and lower in protein and fat. But it is also smaller serving size than in the US. So although I am eating a higher percentage of carb in Japan, my total calorie intake is somewhat less. And this, combined with the additional exercise, is what I believe is responsible for the lower basal I need when in Japan.

The last time I was there it was for almost four weeks, and these results were consistent. And I lost weight while I was there, lending support to the conclusion about changes in exercise and lower calorie intake. In your case, how long do you stay? If more than a few days it must be something similar (otherwise you would quickly acclimatize and insulin would return to normal).

(I just noticed you’re a recent-onset LADA, so you’re probably still producing a lot of your own insulin - so maybe it’s different for you. In my case I’ve had T1 for 39 years).

Hey Jag1

Thanks for the quick and thoughtful response. Yes, I noticed this too on my first trip to Japan. At first I too thought it could be due to the reasons you outlined. However the differences in my case is that I really do not do much less or more walking than at home: I get around via taxi when on business trips. Also, I follow a pretty strict diet of protein, fat and vegetables irrespective of what country I visit. Fast acting carbs in any form are just not part of my diet (bread, rice, etc). Lastly, I only experience this reduction in basal needs in dramatically different time zones: Japan, China, South Asia and India. This doesn't happen to me when I'm in Europe, or Latin America, for example. My trips are never more than a week long, however, so I'd be interested to see what would happen if I stayed longer.

One thought that struck me was maybe the quality of Japanese food in particular. As you know, Japanese consumers traditionally have a high expectation of freshness when it comes to their food (some of the US fast food chains encroachment notwithstanding). It is substantially less processed than what we get in the US.

Your assumption around insulin production is correct. I plummeted from a c-peptide of 1.2 to 0.1 within months of diagnosis and have held pretty constant at 0.1 since then. I can still light up my remaining beta cells with incretin memetics and normalize my BG with a low carb meal, but I rarely use them for fear of burning out what few I have left.

Hats off to you for successfully managing your T1 for so long!

All the best,


I agree travel regardless whether it is work related or pleasure increases activity. It may not seem like it but I bet your actively level has increased.

Thanks Jim - maybe you're right. It's something I'll test on my next trip with a fitbit or similar tracking device to give me a more objective assessment.