All I know is I feel amazing eating lots of leaner red meat. The nutrient content is very high (B-vitamins, zinc, etc.) and hard to get elsewhere. I probably eat 5 lbs of red meat per week. Im in my 50s, fit, and have healthy bloodwork.
I primarily eat vegetarian (eggs, and legumes for protein), but some meat every other day or so. I take supplements and ensure my diet is balanced. Something about meat and red meat in particular does make my body generally just feel significantly better though. More energy, clear headed, etc.
I've thought it might be due to in part to high metabolism. My entire family is quite slender and generally have trouble gaining weight.
