I'm a bit annoyed by the terminology here. CICO is as true as ever from a physics/physiology standpoint and I think it's good to acknowledge that.

_However_ some calories keep you hungry so it's probably _much_ easier to limit your calories on low-sugar than a high-sugar diet.

That's absolutely true for some people. My personal anecdote is that often when I eat something that's high in sugar I crave it more. I've done extensive nutrition planning and found lowering carbs reduces my appetite.

I'm well aware of Gary Taube. His over emphasis of the effects of simple carbs is not entirely supported by science. There is an effect but it's not as strong as he presents it.

If you find avoiding sugar helps you maintain a healthy diet than great, go for it. Do whatever works for you. But if your overall diet is a healthy balance then having a biscuit with tea is not going to negatively impact your health.

You are technically correct, but also missing the point.

It's like saying an alcoholic can still responsibly drink by stopping at one.

Re-read what I said. If abstinence is what you need then go for it. That's not the point I was making.

Re-think the comparison I gave. The point I was making is the fact some people can keep things under control and suffer no ill effects does not change the fact it's an addictive substance whose consumption leads to ill effect.

While you do caveat things in your second comment, both your original and second comment basically minimize the OPs "not even one" stance, even calling it "nonsense". Replacing everything you say with alcohol shows the disconnect; you wouldn't say similar things to an alcoholic who said "alcohol makes you intoxicated", saying that's nonsense (since there are plenty of substances that can make you intoxicated) and then proceed to tell them that one drink is fine.