In the US, there aren't many options for whole, prepared foods (meaning someone prepared the food from whole ingredients, fresh) for various reasons. One that is common, for example, is a rotisserie chicken.
If you go to Asia -- Japan, Taiwan for example -- you'll find cheap, fresh, prepared whole foods everywhere to the extent that many households have very small refrigerators and many families have access to prepared whole foods even without having to expend the time cost of cooking at home.
For a dual-income household, this is a big win.
There's various reasons for this: lower labor costs, smaller land mass/higher density, better access to local/fresh ingredients, more favorable climate and longer growing seasons, etc.
Pretty much every neighborhood created between 1940 and 1990 has no sidewalks, and even after that the zoning is such that the only place you can walk is to other residences.
I don't think it's carbs as such necessarily, but the glycemic index of the foods and their addictive qualities - i.e. how easy it is to way overdo the glucose spiking.
Yes, if you cut the carbs the problem is solved, but there are different kinds of carbs and some kinds in moderation can be eaten regularly without causing big glucose spikes and metabolic disease.
Personally I go for low carb to make it easier, but I still eat limited fruit and starchy vegetables and rice and beans. (Some kinds of fruit do spike glucose and I need to be careful with.)
There's truth here, and, as I understand it, carbs with high glycemic index do have the effect of blood glucose and then insulin spikes which cause metabolic disease and lead to diabetes which is the primary thing that's deadly here.
I don't think it's just the carbs, but they likely don't help in today's society. We became too efficient at packing carbs in our diet and at the same time too sedentary.
Beyond macro-nutrients, what I think the true reason food in the US is bad is because of the other stuff. Many things banned in Europe (which is special because they use science for improving quality of life before profits) are not banned in the US, even though it's an advanced enough nation to be able to deal with the ban and look for better options.
The problem in the US is that profits are of utmost importance. Anything that lowers your costs is good for business as long as it's hard to point at it (does colourant X cause cancer? maybe we need more studies, or just didn't know, we'll try better next time).
Japan, Vietnam, France, Italy, etc. would beg to differ. But they also don’t spray their wheat with roundup so it’s probably better to stay away from carbs in the US just on that basis.
I'm not sure why people think fiber is great. Yes it pushes things through. Yes there are bacteria that eat it. So does other food.
But it also makes you go poop more often, which is bad for your body.
I mostly eat meats and relatively low fiber food. I don't track it closely, so occasionally I'll eat corn and it passes through.
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My point:
"Why fiber?" Actually prove that the generic intake of 'fiber' is good. There are so many different types of fiber, the macro size of the fiber matters(ground pinto beans has a different gastro effect than whole), the actual molecules its made of, etc..
Fiber is good for me because it acts as a stool softener.
In my 40's, I had several bouts of diverticulitis. Hard stool may have been a contributing factor in developing the underlying issue, diverticulosis. I suspect more fiber would have made this less likely.
Later, due to the recurring diverticulitis, I had elective surgery to remove the problematic section of my colon. The surgeon cautioned me to ensure my stool stays soft, so that the place where he stitched my remaining colon back together are at lower risk of opening up. This is a long-term concern, so I'll be careful about it for the rest of my life.
Also, IIUC, straining to pass hard stool increases the risk of swollen hemorrhoids, which nobody enjoys.
Fiber keeps you feeling satiated for longer. Also, it’s bulking effect reduces your caloric intake while consuming the meal since the feeling of fullness can be reached with fewer calories.
Fiber fills you up now by taking up physical volume. Try eating the equivalent of 200 calories of broc vs 200 calories of bread or pasta. The problem is that your body can't digest fiber so the digestive system moves it along quickly!
Fat and protein extends the feeling of satiation by turning off the hormonal signals for hunger.
If you eat an apple, try it with two tablespoons of peanut butter (the kind with only peanuts and salt). If you eat a serving of carrots, add two whole hard boiled eggs.
That is adding so many calories though? Adding the 2 tablespoons of peanut butter is another 200 calories.
An example, im targeting 2200-2400 calories. with 3 600 calorie meals (which tbh is pretty hard to do 7 or 800 is more likely) , there isn't that much buffer to add stuff like thhat.
Is it? An apple is only ~100 calories. 300 calories. You could make it a full meal by adding 500 calories of chicken or beans/lentils + rice to get to your 800 target and that's a very solid meal. A whole can of tuna in water is only ~200-250 calories and another option to add more protein.
No, not over a certain level (low/no fibre would be it's own type of bad).
Carbs give a type of satiety I can't replicate with unlimited fat/protein/fibre. IMHO it's not actually hunger/stomach related but relief from withdrawal symptoms. Carbs are CNS stimulants that trigger serotonin release and very addictive to me at least.
After fasting or eating keto for a sufficient duration this carb specific form of absence/satiety no longer exists. Hunger/appetite stops feeling like a gnawing craving desire, instead it feels like a more neutral empty/weak signal.
Anyway, if eating carbs, best bang for buck satiety is the potato.
The first 2 links have no data available. I only could read the third.
Self reported. Oh boy. No control. haha.
So... is this not science? Its induction?
Since fiber correlates with healthy food, I believe that is what we are seeing. Where as eating sugar and oil has no fiber. However its not like we are having a meat eater compared directly.
I come from chemistry, not sociology. The replication crisis has been kind to me, and terrible for biology and beyond.
Not enough fiber (fruits, veg).
Fats demonized for a long spell.
No time for preparing whole foods in daily lives.
No easy access to cheap, prepared whole foods.
Edit: car-focused culture and zoning laws/planning that result in more sedentary day-to-day lifestyle that magnifies the effect of the poor diet.