The light-headedness is from low blood sodium — hyponatraemia. I went to the doctor and she ordered a whack of lab work, which is why I know sodium is the culprit. My blood pressure and blood gases are normal. I’ve kept a food diary for years.

One of the effects of ketosis is a change in the body’s tendency to retain water — in short, you urinate more. So electrolyte replenishment has to be part of the plan. Hence the Gatorade.

Come to think about it, I’d rather drink Gatorade than take salt tablets, which is what we did back in my military youth.