I don't think that is true. Some expert (Dale Bredesen maybe) said somewhere that a healthy person lacking the bad habit of eating late in the evening will tend to start producing and burning ketones during sleep every night.
Also, many experts are saying that if your body cannot burn fats and ketones, which is unhealthy, you can get it start being able to again by restricting carbs for a while.
Yes there's a lot of hormonal / circadian rhythm effects at play in the evening and early morning. Additionally, you fast while you sleep, so extending that period before and after (not eating late, plus skipping breakfast) helps; 14 hours is a solid fasting amount if you keep it up every day.
Also, many experts are saying that if your body cannot burn fats and ketones, which is unhealthy, you can get it start being able to again by restricting carbs for a while.