Your headline claims IF is “destructive.” I’m female, 57, and have followed a one-meal-a-day pattern for 3 solid years. What has intermittent fasting “destroyed” for me? Let’s see… 40 lbs of fat, an expanding waistline/dangerous visceral fat, insomnia, rheumatoid arthritis, and sleep apnea to name a few. It also cut my thyroid med prescription in half.

The grogginess, etc. you describe are typical before the body shifts from sugar burning mode to fat burning mode, an adjustment that takes a few days to a few weeks depending on the individual. In other words, that’s temporary and acting like it’s negative is lot like calling muscle soreness after a new workout regime negative. Is that part fun? No, but it’s harmless and will lead to better health in the long run.

At best, your arguments here are of the slippery slope/concern-troll variety. You should really stick to what you know.