Any trainer that tells you what to eat and prescribes a specific diet/macronutrient profile or whatever is NOT STAYING IN THEIR LANE!!! I am not a registered dietician (whatever that is) and don't understand what anybody would need one for because eating properly and optimizing your strength and conditioning are SIMPLE!
Here's what I do (notice I'm staying in my lane here!)
I practice Intermittent Fasting (IF) there is only one moving part to this style of eating...
eat in an eight hour window and not a moment later!
Now, I'm not going to go into a literary diatribe regarding all the questions you have regarding it; that's what YouTube is for! But suffice to say IF is the best way to eat if you are a human...eat loads of protein, vegetables, nuts, a little fruit (do your research!) but only do it for 8 hours and FAST FOR THE OTHER 16 HOURS!
Next up; what do I eat?! The same things over and over again; Keep It Simple Stupid! Every Sunday morning I beat 18 eggs and add chopped sausage and bacon then I bake the lot for 30:00, cut it up into 5 equal portions and both myself and My Bride have breakfast for the week all set (we eat similar breakfast on the weekends, but it's made to order vs. in advance)...Lunch is HALF OF THE PREVIOUS NIGHT'S DINNER (no grains, starches or dairy for me!) so essentially after Sunday's "breakfast prep," all that needs to happen is to make a healthy dinner and cut it in half before you eat it!! Now what IS a healthy dinner?! Meat with veggies (salad, cooked, etc.) Finish your last forkful, hit the buzzer on your eight hour eating window, rinse and repeat!
My actual workouts vary in content, length and intensity BUT
I do start each day (no matter what) on the Airdyne bike at either 345 or 445 for 15:00 of Low Intensity Steady State cardio; it gives my metabolism a kick in the pants for the final 5 or so hours of my 16 hour fast and if you REALLY want to drop bodyfat, do IF and LISS
before the roosters crow :)