When I was growing up the recommendation was to eat a lot of grains/carbs and avoid red meat. Beyond incompetence I think partly this was because cheap calories were needed historically to feed a manual labor force. Now that much of our labor is knowledge work, and people live sedentary lifestyles unless they exercise, the dietary recommendations should be altered. Whole foods and animal proteins, lower calories required, two meals a day.
And economics. Expensive food (protein) has lower margins. Cheap food is profitable. The high margin pasta dishes and alcohol keep restaurants alive (steak houses famously have almost 0 margin on steak), and it's the same for the entire food industry.
The USDA represents American agricultural industry - not consumers. Eight servings of carbs a day on the food pyramid was essentially a license to Americans to buy as much carbs as they wanted.
Could you give me more information about the low margin of meat? This is interesting. Would have assumed that meat would be a win for fast food industry.
