I think it is important for health to have a long period without eating. Drinking water (unless you’re asleep ) or naturally unsweet beverages (black coffee, matcha tea etc).
However, when you get actual hunger weakness, both the body and the bacteria biome in us need food.
I can only do 12 - 14 hours. Usually only 12. It is what it is. I know the difference between low blood sugar in the morning (caused by eating carbs the previous evening) ( a bit of a sweet tooth feel and which should be ignored) and true hunger, which comes across as a body weakness and a craving for animal protein, and it’s time to eat.
I combine keto and IF. Definitely NOT an eat anything approach. Eat between noon an 6 pm. Lost 35 lbs quickly. Weight has leveled but my waistline has decreased a little over the last 18 months. I’ll never go back to three meals a day.
For evening meal, I sometimes instinctively want "only" vegetable + dairy ---- like a big lettuce salad with side of lite cheese, or big bowl of tomato/vegetable soup with rice crackers and add chunks of lite cheddar to the soups. For dessert -- some dried papaya or a fresh fruit, for example.
A few nights a year - I'll only have a big bowl of cereal with milk if I return home late from work - or, a large bowl of plain yogurt with honey and berries mixed in it. BTW, a big bowl of yogurt at night makes for A VERY SOUND & GOOD Sleep -- I recommend that, if you have sleeping troubles.
I take an assortment of multi-vitamins every day as well.
This practice has kept my weight at about 134 as a woman. Men need much more calories & more "beefy" stuff, so not advising this for men.
I'd say the evidence that the conventional advice to eat low fat, carb heavy meals has pretty blatantly failed people in spectacular fashion is crystal clear. Heart disease isn't really down but diabetes and obesity are through the roof. But too many people staked their careers on that advice, their pride has blinded them to the obvious. And that is that on balance another way is needed.
What works to lose weight is suppressing insulin (see the work of Dr Joseph Kraft, among others). Carbs do the opposite, insulin spikes and you get fat if that's your primary form of food. Low carb / high fat spikes insulin less. Fasting doesn't spike it at all, in fact it lets it fall to it's natural level. That's why it works to lose weight. And of course eating less to lose weight is common sense. What they should say, though is that eating less often will result in weight loss. Time is a key factor.
People say though that if you fast you'll die because you aren't getting nutrition. That's false, plenty of evidence on that. Burning your fat stores releases various nutrients and vitamins and the blood work shows it clearly.
Bottom line: people should do what they want but for me, intermittent fasting works and my own health, as indicated by hard measurable factors, has never been better than has since I started eating this way (mostly one meal a day).