The Facts: Let's make one thing clear before we begin. Carbohydrates eventually turn into sugar. In 1961, the American Heart Association labeled dietary fats as the enemy. High protein, low/nonexistent fat and mid-high carbohydrate diets became popular. This error somehow became widespread, and sadly became widely accepted and recognized. Funny enough, this grain, fruit, vegetable and low (especially saturated) fat diet had NOT BEEN TESTED ON HUMANS!
The best and most detailed clinical trials of the past 10 years demonstrate that a high-carbohydrate diet has worse outcomes for health in terms of obesity, heart disease, and diabetes than a diet higher in fat. On a higher-fat diet, people lose weight, and heart disease and diabetes markers improved. In the 90's, a researcher studied women on a rigorous low-fat diet and discovered that their HDL (good) cholesterol dropped precipitously, and much more than it did for men. Can you believe that? Low carb diets are wrecking cholesterol levels.
Finally tests were concluded in the 90's, and surprisingly did not get published until 2006 that it was causing issues in the American populations. Could it be coincidence that between those years, obesity skyrocketed?
What we should change: Eggs fried in butter make a better lunch than a salad and a smoothie, and a steak salad is preferable to hummus and crackers.
Instead of oatmeal and lowfat yogurt (which is high in sugar), start your day with eggs, bacon, or sausage. And for a snack, just a big hunk of cheese and a couple handfuls of nuts instead of a piece of fruit (sugar, once again!). Hamburgers are also fine. Skip the bun, or do a true "whole wheat" if necessary. High fat Greek yogurt is better for a snack than something with just carbohydrates.
Why eating Paleo is unreliable: The problem with paleo diets is you have to go back tens of thousands of years to figure out how people ate, and you're relying on a sketchy archaeological record to do so. If we go back even 100 years, it is well documented that your ancestors ate three times more red meat than we do today, and consumed far more butter and more lard before the heart disease and obesity became out of control. We can leave the diets used 10 thousand years ago (paleo) to the imagination, and leave it at that.
Bottom line: Americans have cut back on saturated fats by 15% over the past 30 years, and we are more unhealthy than ever.