1. There is no essential daily carbohydrate level.
2. There is an essential fat level.
3. There is an essential protein level.
4. Your brain uses 25% of daily carbs and so if you need to use your brain you actually now have a certain amount of carbohydrates needed. 25% of 50 grams is 12.5 g sugar and so you probably need more if you want to do any sort of intellectual exercises in your day.
5. Never drop carbohydrates below 10 % of calories or your body will just convert amino acids to sugars to burn and that is a waste of money. Furthermore ketosis and peeing on keto-sticks is un-neccesary to benefit from low carb diets.
6. All carbs break down into simple sugars and this is why fat free oatmeal and lucky charms are basically the same in your system. Its just that oatmeal has some more fibre and may fill you up longer and lucky charms has weird colours and artificial flavours that may have negative health effects.
7. Drinking tons of water will not help you burn calories but it will keep you hydrated which will make you less hungry (through mistaking thirst for hunger).
8. There is a major difference between a diet that will make you 'peak' and be in great shape for contest day and a diet that will help you be in 'good shape' all year around.
9. Most popular historical based diets are silly (ie Paleo diet) -no one really knows how people ate around the globe 50-250 million years ago- we can assume they ate other animals when they could, perhaps other humans, and lots of leafy plants, bugs, worms and whatever they could get their hands on. They did not eat buffalo steaks with pineapple and goji berry salsa with a side of coconut water- modern paleos can only eat such a diverse geographic range of foods due to transportation and gas guzzling machines 'serving' the first world desires.
10. Agriculture is about 10,000 years old, humans ate lots of wheat in Ancient Egypt and Ancient Greece, rice has kept Asia flourishing for like 7,000 years (at least) and so YES humans can 'naturally' eat lots of carbs and 'man made' foods like bread, butter, wine, sausage, olive oil and spice it all up to make it tasty. Hence why Marco-Polo even went on his trip.
11. Strength athletes have historically eaten more meat then non-atheltes, hence why Aristotle says that moderation in portions of daily meat for a weightlifter is different then moderation for an average non- weightlifter.
12. When Socrates was condemned to death in Ancient Athens, when asked what his punishment should be he said-"Free meals for life". Which was the custom reward for an Olympic champion.
13. Some people have unique health conditions that can make weight loss/gain virtually impossible unless medically treated. Ex: low thyroid, low testosterone, diabetes, allergies (real ones), and even some of my research points to the idea that having an ADD type personality actually makes it almost impossible to 'stay consistent' on a plan- and consistency is the true secret to any good diet, It takes time and we need to program in habits so we can live on a desired auto-pilot.
14. Eating food is more then just calories, it is a HUGE human social behaviour such as 'family dinners', 'lunch with friends', the school meal hall or cafeteria where all kinds of socializing takes place, as a religious custom of feasting and fasting, and so we cannot expect to enjoy life if we say no to every event and person that does not fit into our chicken breast and broccoli diet or does not want to agree on the merits of veganism or whatever- just eat together!
15. The ethical philosopher Peter Singer will say that you are a privileged human being if you drank anything beyond tap water in the last week AND also had access to clean tap water. Since you are reading this on the internet, then count your self lucky and very privileged and realize that people are actually starving to death while we throw out egg yolks for our fat free omelettes and turn down perfectly good bread. Something to think about.
P.S. -while eating meat is a biologically and historically sound practice, there are many good ethical arguments against eating meat. Whether it is based on the assumption that animals have rights or instead based on the simple idea that animals suffer pain (furthermore they suffer the inability to satisfy their natural life preferences) when we treat the solely as food and not as fellow animals here on earth. SO if you ask is eating meat bad? Ask yourself, would I want to live a short live just to be food for Martians?