This may be related to ones number of copies of the amylase-coding genes.

Put a saltine in your mouth and start chewing it, without swallowing. Note the amount of time required until it starts to taste sweet.

Anecdotally, I never taste sweetness from this test. And I do not feel satiated by high-carb foods. I could eat spaghetti until I'm basically the gluttony murder victim from "Seven". The satiety signal from carbs is almost completely absent. The feeling of fullness only comes from the physical stretching of the stomach, or from other macronutrients.

That's why low-carb diets work better for me. I eat less when only eating foods that make me feel as though I have eaten at all.

That's an interesting theory. I'm curious though -

If you are low in the amylase enzyme then I would actually expect carbohydrates to NOT cause weight gain. Doesn't that enzyme break down complex carbs into consumable (usable) simple sugars?

Both the salivary glands and pancreas produce amylase, but in different isoforms. Salivary amylase is ptyalin, coded by the AMY1 gene. Pancreatic amylase is coded by AMY2. Humans have multiple copies of these genes, and more copies means more amylase is produced. Someone with 4 copies of AMY1 can still digest starch, but someone with 16 copies of AMY1 might have most of their eaten starches reduced to oligosaccharides long before their ptyalin is inactivated in the stomach. More copies of AMY1 is directly correlated to historic populations with higher starch consumption.

Gut biota will also make their own amylases.

An amylase blocker causes carbohydrate malabsorption, and that is about the same as a lactose-intolerant person consuming lactose. The starches end up getting fermented in the intestine. The gut biota will consume most of them, but I suppose it is possible they might drop some on the floor for the intestine to absorb.

My hypothesis is that the slower rate of digestion of starch produces a lesser effect on perceived satiety.

Here's the rub: it's much easier to overeat with carbs and sugar than with protein, fiber and fat. A lot of people wouldn't blink at 80g of carbs from fries or desert but eating four apples in one sitting is much more difficult.

Honestly, hunger and satiety have a surprisingly large physiological component so is I think its some sort of psychosomatic thing based on current trends.

Me? I get full on food, including carbs.

Sometimes on a weekend day for a treat I go to a cafe in the morning. When I'm there I eat a donut and a bagel and that will be the only thing I eat in the whole day, I feel full after eating it and I am plenty satiated for the rest of the day even though "broscience" tells me I should be starving again a half hour later.

But do you get that feeling faster eating a steak than bread or cookies, in terms of total calories consumed?

i myself get that feeling of being full faster from eating carbs. a glass of soda can effectively kill my appetite before a meal