I can tell you what I eat, but it’s probably not applicable to you. I can share my system, which may be more useful to you.
About me: After losing 75 lbs of fat, I am no longer trying to lose weight, I’m trying to increase muscle and lose fat in equal amounts, so that there’s no net change. Additionally, I want continued improvement in my IR (before I started my A1c was 5.8). Lastly, I want maximum cognitive function. To those ends, I want to my body to use burn fatty acids more than (or at least equal to) glucose. Nutritional ketosis isn’t sufficient for my goals, I maintain therapeutic levels (> 2 mmol) of ketones most days of the month via a large amount of fasting. I try to eat Paleo, but not always VLC. I eat lots (and all kinds) of veggies, and have not eliminated fruit. I don’t typically track macros, but meals at home contain about 10% of calories from carbs, 50-75g per day.
About system: I’ve found that tracking BG is more useful than ketone levels when assessing the impact of dietary changes or exercise. My daily weight loss or gain was more closely correlated with changes in BG than ketone level. This supports the insulin hypothesis, as promulgated by Dr Fung and others. High insulin levels cause weight gain and high BG inhibits lipolysis. So tracking BG is an indirect way of monitoring insulin.
Measuring BG provides immediate feedback on how my body is processing a meal. Ideally, meals shouldn’t increase BG by more than 25 mg/dL. If the 60 minute postparandial glucose is a lot higher than it was pre meal, then the meal had too many carbs and/or too many calories.
With exercise, an immediate BG level isnt enlightening,
but a delayed BG reading is useful. When exercise was too strenuous (in duration, intensity, or frequency), my BG will be elevated (from basal) the next morning. With the right amount of exercise, it will be lower than normal.
Improvements in BG levels over time is another example of a NSV. Psychologically, this is important because maintaining motivation is crucial. In six months, my fasted glucose has improved by 20 points. My postparandial response has also improved.
Many people achieve their goals without diligent tracking, troubleshooting, and tweaking. Unfortunately, that doesn’t work for all, some of us need to be more conscientious about the process.