No, they're not almost pure starch. They are about 17% carbs (including 2% dietary fibre and 1% sugar, the rest being digestible starch).

For context, corn chips are over 60% carbs. Vegetables (even "bad" ones with less protein and more carbs) are actually often kinda healthy.

You are looking at wet weight, which is highly misleading. You should be looking at dry weight.

> In general terms fresh potatoes contain ~20% dry matter (DM) of which 60–80% is starch

That's 60-80% by dry weight. I assure you that the types of potatoes eaten in Eastern Europe contain approximately 109% starch by dry weight.

They're high in starch, that's not necessarily a bad thing. Potatoes are a satiating food, and its starches can improve microbiota. However they're often consumed with excess fat which, on top of adding more calories quickly, can yield a higher insulin response. Potatoes themselves aren't low-GI foods either. Leptin resistance is often associated with weight gain. In general high fiber foods avoid those pitfalls.

Potatoes contain 60-80% starch. They are generally low in other nutrients, especially protein.

Then you say "however they're often consumed with excess fat" --- yes that's the only way they can be reasonably consumed because they taste like powdered chalk.

They're quite high in potassium, vitamin C, B6, niacin, folate, not to mention various minerals. To say it's low in other nutrients is just plain wrong.

When you say "quite rich," that means very little. Quite rich compared to what? Certainly not to any green leafy vegetable you find on a supermarket shelf.

Potatoes are typically boiled for a long time before eating. Boiling destroys vitamin C and many others as well. Now maybe boiling is not how you do consume potatoes but that's how most people consume them.

> Quite rich compared to what?

On par with meat, pulses, legumes, vegetables, fruit. Compare for yourself, it's not hard to find: https://nutritiondata.self.com/facts/vegetables-and-vegetabl...

> Certainly not to any green leafy vegetable you find on a supermarket shelf.

Yes, those too. They all have different profiles. Generally leafy green vegetables are NOT high in everything at once. They're high in vitamin K and C. That's not terribly unique - many plant foods share this characteristic.

Add to the fact, green vegetables are not as satiating as potatoes. The soluble fiber tends to be fermented quickly. They fulfill a different purpose.

> Boiling destroys vitamin C and many others as well.

Huge overstatement. We generally cook our vegetables as well, a good portion of the vitamins stay intact. In fact cooking increases bio-availability. It doesn't really matter that there is some loss in the process.

> Now maybe boiling is not how you do consume potatoes but that's how most people consume them.

I don't know where you get this idea. I roast potatoes, but all the same cooking in hot water is a gentler cooking method.

All of which to say, discounting potatoes entirely owing to some notion of a poor nutrient profile is absurd.