I was thinking of doing this but with a glass of milk in the morning to neutralise acids in my stomach to stop hunget pangs. Would that count as breaking a fast?
First question: do you have acid reflux? Second: did your doctor recommended milk?
To answer your question, yes, milk has (lots) of calories. I wouldn’t drink it during a fast, but if you have a doctor’s recommendation, I’d go for 0% milk to reduce the calories. IF is useful for more than one purpose. First, (for most of us) it restricts the timeframe for calorie intake and helps you reduce overall intake. Second, are all of the fringe benefits like autophagy and more regular energy levels. The fringe benefits don’t occur if you break your fast partway through with calories (like your milk).
All of that said, if your doctor is recommending it, far be it from us to refute that recommendation… but maybe get a second opinion from a different doctor. That’s some super outdated advice. If you’re not following doctor’s orders, you need to ask yourself what you want out of IF: do you just want to lose weight, or do you want the fringe benefits. If you just want to lose weight, you can probably get away with one glass of skim milk if that’s all you consume and it helps you finish the fast. If you want the other benefits, you lose them when you drink the milk. People like to think that something like IF is all or nothing, but people have had success “dirty fasting” if all they’re going for is weight loss. You do what works for you, just make sure it’s actually working for you.