zoe.com
They analyse your body's ability to process fats and sugars (you have to eat some not very nice cookies and take a blood test and wear a glucose monitor). You send off a poo sample and they analyse your gut microbiome.
You get scores for all of these and then foods are given scores depending on how you have scored. So I have bad fat processing but good sugar, which means I can deal better with carbs than saturated fats. I eat a lot less cheese than I used to, but have MASSIVELY expanded my diet and eat far more interesting food than I used to. I no longer think about calories, make and eat healthy cakes, ice creams, brownies. All the treats I used to avoid because I thought I'd put on weight.
There is an app where you can track what you eat and get tips for eating more healthily to suit your body.
I'm never hungry and have lost over a stone in weight - even though that wasn't the aim, my BMI was middle of normal and is now the low end. More energy than before and would really recommend it.
Having said that - not cheap - about £300 for the testing I think, then a variety of packages, monthly, 4 monthly, annual. Cheaper per month if you buy the year up front, and I'm glad I did (again just under £300).
I'm just about to renew my year. Wasn't going to bother as I no longer use the app to track, but I do use it to get recipes and see what online recipes would potentially score for me (just imported a recipe for a loaf that looks interesting). I've also stored a lot of my own creations in the app.
They have a podcast that is well worth listening to - to get a feel for what it's about. Science driven - lots of involvement from Drs, epidemiologists, nutritionists.
It's been life changing for me 🤷🏼♀️