Something else is serving-sizes, as we eat double or triple of what we should eat. Before agriculture people ate very little relatively high-nutrition food, after agriculture but before industrialization people ate a bit more less- nutritious food. But now we are eating a lot of highly nutritious food.
I have a book containing a list of different ingredients with their serving size and nutricional value. These serving sizes are sometimes dictated by practicality (things that come in portions like sausages or slices) but the rest are standardized to be all around 100Kcal. A serving size of red meat is usually 30g, fish goes to around 50g, chicken 40g. Meanwhile there's lettuce with an obscenely huge serving size of 3 cups
With how most people eat (Big slab of meat + vegetables and/or starch) it is very easy to overeat and meet your daily nutritional requirements in a single sitting, only to then have two other similar meals.
Even I, who eat very little meat, know how ridiculous 30g is, so you are supposed to « save up » these portions for a single meal a day (I do it weekly) and eat very little meat for the rest of the time, same with starches and the sugar I love so much. I also eat mostly aged meats, they are usually high in fat, but you eat so little of them that you come-out the other end with a win.
When it comes to eating there is a lot to get used to, something I have found works for me is trying to do as much as you can yourself. In an urban environment this means baking your own bread, not getting too efficient with it, maybe making it weekly, leaving starches mostly absent for the rest of the week. Raising your own meat is also great when you can, their life cycles, aging and processing serve as moderators for consumption if you keep it small-scale. Moderating mechanisms like this give you a why when lowering the volume of food you consume
Right now I am proofing the last of a batch of croissants I made last Monday, my kitchen was too warm while making them so shaping them was impossible *thus no pictures since it is offensive to call those things croissants*, but I rather do this once a month and get good than to visit the bakery next to my house every-time I have a crave for bread.