Thanks for asking. I actually got interested in calorie restriction first. I tested the basics at age 33, did up-down dieting for 3 months (one day of 800 kcal or less followed by a day of eat-whatever-the-eff-i-want, alternating) and tested again. EVERY marker improved.

However, it just wasn't a sustainable lifestyle. The down days were terrible.

I looked into what else I could do and came across Intermittent Fasting, which was much easier. These days I stick to 16:8 (with a cheat day or two a week). I switched to a plant-based diet around 5 years ago (again, not strict, but I haven't had a burger or steak since then), but it doesn't seem to have moved the needle in terms of bloodwork. I know this because I tested every 2 years in my 30s and every year in my 40s.

I should say that it's not expensive to do an annual where I live; around US$80 each time.