The hole in my "discrete eating" theory is the missing importance of nutrition. There was a time when taking mega-doses of vitamins was all the rage. This was followed by a period where experts began to view vitamins as a waste of money and seldom necessary. I think we are now going to enter a period of time where vitamins will again play a role as a nutritional scoring mechanism for food. Now if you are not keeping score, you really can be considered irresponsible.
You cannot erase a nutrient deficiency by simply eating at discrete times. Therefore nutrition MUST play a role. What is interesting is that one's nutritional requirement changes depending on what is being eaten. People who eat only meat have a very low need for vitamin B1. But eating a lot of carbohydrates causes the need for vitamin B1 to go up. That is just one example that I am aware of.
Well what happens if the diet has a deficiency in a vitamin for a long time? There are known diseases that are caused by vitamin deficiencies. But if one goes for extended periods of time with a deficit in one vitamin it may create less obvious problems that are difficult to pinpoint. Let me give a similar example using a car:
If you drive a car low on oil for a period of time it may cause hidden wear in the engine. If you drive with the tire pressure too low for a long time, it can affect gas mileage and wear & tear on the tires (tyres--if you are in the U.K.). Both of these problems manifest very differently than having "no oil" at all or having "no air in your tires", but they are still problems.
However, we are not talking about a car. We are talking about the human body which is even more complex. An extended vitamin or mineral shortage might cause problems which are currently unknown. What is even more perplexing is that certain problems which seem to be opposites may be caused by the same deficiency (as happens with thyroid hormone deficiency; a low level of thyroid may lead to excess weight gain or a person being under weight). Another difficulty is that of acute need. Just as one temporarily needs to breathe more after holding one's breath, there may be an acute need for a vitamin caused by certain conditions or ailments. To EVEN FURTHER complicate the matter, that acute need may be localized (like when one cuts off the circulation to the legs from sitting too long).
Certain diseases, infections, and illnesses may cause an acute need for some vitamins and minerals. It is common knowledge that type 1 diabetes can happen after a viral infection. Is it possible that there was an acute, possibly even localized, need for a vitamin or mineral? Many experimental models may be insufficient to help us. Certain deficiencies, over a long period of time, may cause damage that would never appear in a mouse or a rat because they don't live long enough. There is also the possibility of intermittent deficiencies that may be difficult to pinpoint because one is currently eating just fine.
Now some bad news. If you drive your car and scrape it along a brick wall, driving the car more carefully doesn't repair the scrape. The human body may actually be able to "unscrape" itself from some of our reckless nutrition, but chances are that much of that damage may be permanent. So if you have difficulty losing weight, even after getting your nutrition right, it may be time for additional medical intervention.
So what about the ideal carbs, fats, and protein levels? The funny thing about that is it depends on what one is eating and what deficits need to be filled. Changing the carbs, fats, and protein would also change one's micro-nutrient needs. Preferred foods and digestive issues must also be taken into consideration.
This is an optimization problem. As such, it would best be solved by a computer.
Some further speculations:
My guess would be that if one wanted to feed their children a SAD (Standard American Diet) then it would be extremely important to ensure the child is meeting all of the nutritional requirements for their age (not the same as an adult). That is not something I did and my entire family is paying for it.
Supplements are only necessary if the diet is deficient or the person has a pathological need. It is best to try and get the nutrition from food if possible or acceptable.
Metabolizing carbohydrates requires more nutrition than eating meat and therefore one should try to consume more nutritious carbohydrates.
If carbohydrates are going to be eaten, then animal products (flesh, dairy, eggs) can be minimized to simply meet the B12 needs if ethically acceptable. Otherwise animal products can be eliminated if taking a B12 supplement.
Consuming fructose may require different nutrition than starches because fructose is metabolized differently than starch.
Improving the diet can do some dramatic repairs to the body, but it cannot fix everything. It won't make the blind see and the deaf hear. It may not even cause you to lose weight. There are too many expectations made about diets. Nutritious food must be considered before any scheme to supplement nutrients, and nutrition must be considered before any scheme to reduce calories.