Apparently, when shifting to a low-carb diet to a high-protein and high-fat diet, your body needs time to develop the right enzymes to metabolize fat instead of carbs for energy, and this process takes 2-3 weeks.
So THAT explains why, when I have tried this in the past, I feel sort of odd and moody and I lack energy for anything requiring endurance or strength!
Lately I have once again tried to get away from carbs, especially flour and starches but also sugar to a degree, and it’s been going OK, but I haven’t taken a long bike ride on a hot day yet. I haven’t pushed myself, really. And I haven’t avoided carbs completely, just cut them way back. My main sources of carbs now are pizza once or twice a week, and my daily drink or two at night. Occasional pretzels or chips of some kind, maybe once a week. Almost no bread or potatoes or pasta (though I make exceptions once or twice a month for delicious hard-crusted “European style” breads, and potatoes once or twice a month too, like hash browns with morning eggs).
Today looks like a good day for a long bike ride, it’s cool, about 65 deg at 8 AM. A few days ago, we were setting records for heat, and the last few days, it’s been cool. Strangest spring weather ever!
So based on my personal experiences over the years, with both eating and exercise, I think I have learned what works for me: low-carb when my physical energy needs are low but mental energy needs are high, like sitting on my ass at work and trying to think and type on computers at the same time. But when that ratio is switched, like during long bike rides, I need some carbs to feed my body because it wants more fuel for high energy requirements. This could be because of my mild hypoglycemia.