A better way to say this is that fructose adversely effects the liver and brain, but it is not, in itself, a "toxin". Like a lot of other things, it can become toxic.
The obesity that is acquired from fructose is, unfortunately, usually intractable. Surprisingly, if fructose is eliminated from the diet, the fat that the liver acquired from it easily disappears, in a matter of weeks, reversing any fatty liver disease that the person may have had and improving metabolic markers.
Unfortunately, the fat mass itself becomes impossible to get rid of, keeping the person at high risk for future metabolic problems and diabetes.
This is usually the result of hypothalamic damage, where leptin is simply no longer communicating, the body's fat stores, to the brain. That fat is then never burned, as the brain can’t "see" it. The person continues to be a soft pile of fat, even with no significant visceral or entoptic fat remaining.
You would think that, at least, some of the battle was won and the person can simply remain visibly fat, while maintaining metabolic health, but it doesn’t work that way. Because the safe subcutaneous fat storage space is full, the person easily regains visceral and entoptic fat, so they remain constantly teetering at the edge of metabolic dysfunction. This is aside from the fact that this excess subcutaneous fat interferes with immune and stress hormone function which affects blood glucose.
There is no known treatment for this, but leptin's function in the brain is being closely studied and hopefully there will be some kind of treatment in the future. In the meantime, most doctors simply blame these patients because of their past dietary decisions and they are constantly being advised one diet after the other, to no avail.
This is why you need to stay away from sweet things. The saying usually goes that "the dose makes the poison", but when it comes to sweet "the sweetness makes the poison".
2. People with metabolic syndrome/obesity have a bad relationship with carbohydrates.
People with metabolic syndrome/obesity have poor blood glucose regulation, which makes their relationship with all macronutrient "bad".
3. If you continue with the "keto" diet, improved metabolic numbers will not change. If they do, it's because you are consuming too much protein.
Diabetes is not a "disease of numbers". It is a condition of poor blood glucose regulation. You do not obtain blood glucose regulation by having "improved numbers". Stop chasing symptoms with macronutrients.
Metabolic numbers are usually improved, in the beginning, because when less dietary glucose comes in, there is an improvement in insulin expression/release. This occurs with all diets, not just "keto". The only advantage "keto" has is that it can be followed for a longer period of time, affecting blood glucose more profoundly. These diets will also not reinforce the starvation adaptation like calorie centered diets do.
But we know that all diets have a dismal long term efficacy. This is because for most people, even though blood glucose lowers in the beginning, its proper regulation is never acquired. Until proper blood glucose regulation can be sustained, the condition will progress. This is why a diet that can be followed for a long period of time is the ideal as it gives you a better chance of continuing to affect blood glucose long enough for insulin expression/release to follow suit.
So, no. Deteriorating metabolic numbers have nothing to do with "too much protein". They have to do with the inability to stabilize blood glucose homeostasis, even while adhering to a proper diet. Other issues that can be at play, which affect blood glucose regulation, is caffeine intake, not enough exercise, too much fasting, erratic meal and sleep times.
4 - 100 grams of carbohydrates a day, is not low enough for "some people".
100 grams of carbs a day is a low carb diet. If you do not see results with 100 grams of carbs a day, you won’t see results with anything less than that. This is because the differences between 100 grams of carbs a day and 10 grams of carbs a day, to the body, are negligible if the carbs are not coming from sugar or grains. So, when we speak about carbs, we are talking about whole, non-starchy vegetables only.
Continuously driving carbs down will not get you anywhere, except for temporary changes in numbers. As I stated above, diabetes is not a "disease of arithmetic". There are no "some people" who can’t tolerate 100 grams of carbs a day. There is no one who can tolerate sugar or grains. Usually people begin to notice this and they end up eliminating sugar and grains from their diet. Then, when they start seeing results, they claim that 100 grams of carbs a day is too much. It wasn’t the amount of carbs, it was the quality of carbs, that made the difference.
5. Low carb/"keto"/carnivore cannot be "cures" if the person goes back to being a diabetic when they return to their "normal" diet.
This is all mental gymnastics and word play. First, there is a no "cure" for obesity/metabolic syndrome/diabetes. All three are chronic and progressive. They can only be "reversed" at their starting stages or put into "remission" at their end stages.
The only way they can be reversed or put into remission is through obtaining and sustaining proper blood glucose regulation. The best diets for affecting blood glucose are low carb/"keto"/carnivore. The moment you lose your blood glucose control, you will return to obesity/metabolic syndrome/diabetes. This can occur while still adhering to low carb/"keto"/carnivore diets, as described in the above post.
6. Having lots of fat in the diet, helps you maintain a fast.
Eating large amounts of energy, to then be able to not eat, cancels itself out. All you’re doing is eating everything you would have eaten during your fast, before it begins. Not only is this dumb and useless, it causes a doubling down of the metabolic adaptation that enhances fat storage, over time.