eating too much sugar (and refined/processed carbs) is as much of a contributor to Americans' health problems as just about anything.

While it's not necessarily the main factor of many chronic illnesses, it seems to be a major contributing factor to more problems than most people realize (most people just think of obesity and type 2 diabetes but those are just the tip of the iceberg).

In addition, problems associated with eating too much sugar seem to increase exponentially with age (the older you get, the more excessive sugar becomes a ticking time bomb).

It's convinced me to shift my diet in a more ketogenic direction. That being said, I'm not ready to go full-fleged keto as I'm yet to be convinced that foods such as whole grains and dairy are per se bad for everyone (at least, if consumed in moderation by an at least moderately active person in the midst of an otherwise low inflamatory diet).

But even with dairy, it's convinced me to cut back. For example, for a long time I believed that it was important to drink a lot of milk in order to get enough protein, calcium, and vitamin D. But I've recently learned that, in order for calcium to be sufficiently absorbed into bone tissue, a person needs much more vitamin D3 than is in fortified milk, in combination with vitamin K2 and magnesium. Along those lines, most people who drink a lot of milk are probably doing themselves more harm than good, especially if they aren't getting enough D3, K2, and magnesium (and the vast majority of people are deficient in all 3 of these).

Put another way, it's much better to consume just a little bit of dairy while getting enough D3, K2, and magnesium than it is to consume a lot of dairy without getting enough of those other nutrients.

On the flip side, foods that seem to contribute the most to greater overall health and longevity include leafy greens and "good" fats. Most Americans still grossly underestimate the benefits of shifting their diets in this direction (and away from all the sugar and processed carbs).