Hi, just wanted to share my accomplishment because some people here think that low-carb is extremely unhealthy and inadequate for this sort of cycling (long distance, moderate speed).
I eat less than 50 grams of carbs per day, moderate protein, and tons of fat (mostly saturated) usually from butter, cheese, coconut oil/milk, palm oil, pork belly, duck fat, olive oil, eggs... I also eat lots of low-carb veggies, really just okra and green beans. I also drink coffee everyday and eat lots of salt (sea, Himalayan, etc).
Last night I had about 0.75 lbs of grassfed liver with veggies and sour cream. Woke up this morning and took a neon-yellow piss (the B vitamins from the liver) and then had nothing but coffee with some coconut milk and coconut oil. Did 78 miles (my all time record; I'm not an avid cyclist) on 5.83 hours (without eating during it) which is 13.4 avg mph. Single speed bike. This was from Westchester to NYC, by the way (yes, in today's super foggy weather). I will do 100 miles sometime this month.
Any other low-carb cyclist here? Please share your accomplishment.