Yes. I agree with you that diets can work for different purposes. And I think any educated responsible person needs to look at what's out there and then pick out the best ideas for them. I also agree that I don't need the special tests. I did appreciate the basic overview of the book, which helped me put things like Atkins in perspective.Having flipped through Ultrametabolism, it appears to have a lot of pseudoscience and half-truths.
When I was trying to assemble the "ideal diet", I read and thought a lot about the different diets (and level of activity) of various cultures around the world, French, Mediterranean, Okinawan, Inuit, Paleo, Atkins, South Beach, low-carb, low-fat, high-protein, dairy, non-dairy, fish, soy, etc. I can't say that I was impressed with any correlation between what people eat vs. their level of health (other than avoiding fast/junk food or eating in excess). I can't say what's right for you, but personally I tried to take bits and pieces of what I thought was useful.
The diet that helped me lose 70+ pounds is quite different from the diet that I'm using to keep it off. Just as in running, I had to listen to my body to see what it needed, as it was changing over time. I'm fairly certain that what worked for me, won't work for you. This makes sense, though.As a teacher, I assume that you're able to look through all the data and pick out what parts apply to you through trial and error.
I have a friend who is a doctor that has gotten the special metabolic labs, dna testing, and is into the pseudoscience. He's a great guy, but still overweight, doesn't exercise much, and has a high stress life. I don't need special tests to know that I'm living a healthier lifestyle.
In the end, what has really helped has been reading a lot, comparing different ideas, and then refining my own viewpoint. Basically, I'm back where I was, which is focusing on whole foods, minus the loads of bread, pasta and beer I was taking in. Oh, and I feel a whole lot better now about fat, and a lot worse about the fact that all the snacks around work are usually sugary carbs like donuts. No more of those timebombs.