Hmm, OK. What are “macro nutrient ratios,” though? How are they calibrated to an individual?[/quote]
Macronutrients are the big three: protein, fat, and carbohydrates. They are what contains calories in a given food. Their ratio is how much of your total intake each makes up. If you get a 1/3 of your calories from each macro you macronutrient ration would look like this: 33/33/33 (well, you know…) protein/fat/carbs.
They’re calibrated by experimentation. No one knows what will work best for you.
Just start with a 1/3 of your calories coming from each major macro nutrient. See what happens for a few weeks/month and adjust from there.
That said, I would not get too caught up in it. Eat a ton of clean food, maybe track your total intake for a few weeks and see what you really are eating.
That at least gives you a baseline to work with. Trying to design a “perfect” diet will get you nowhere but paralyzed by analysis (analysis paralysis is not good).