Some years ago my doctor, who is an M.D. but a holistic one, did several tests on me and suggested I not eat sugar, not eat grains (especially wheat) and instead eat meat, fish and oils, such as butter, olive oil and coconut oil.
These days this is commonly-known as "the paleo diet," although it wasn't then. The man who promoted these first was Weston Price...and this appears to have been back in the '30s.
I didn't notice any changes physically (wasn't overweight and had good energy) but I did notice something: my brain worked better.
Your brain is mostly fat, anyway, and I was consuming a lot of fat. In college, I used to make my roommates have fits by eating half-sticks of butter in front of them.
Even though the diagnosis didn't exist when I was a kid, I would today be diagnosed with Attention Deficit Disorder without Hyperactivity, which is a fancy way of saying I daydreamed a lot, was bored, and didn't do my homework. For one thing, the functioning of my brain went up and down, so I compensated by day-dreaming.
These days, ADD has pretty much exploded, as has the prescriptions for Ritalin to treat it. For that matter, obesity and diabetes has exploded, too.
It's been known for quite a while that what a pregnant mother eats has an effect on the fetus, sometimes profound.
I oftentimes wonder, as do many people, what is going to be the long-term effects on humanity of an adulterated food supply. Tell the truth, it's like navigating through a minefield, and I sure don't believe anything the government says.