Fixing obesity does not improve metabolic health?

Everybody knows that when they gain weight, they are at a higher risk of metabolic diseases and many were lucky enough to reduce their medication for blood pressure or to lower their blood glucose or cholesterol levels when losing some weight. 

Yet Dr Lustig calls this connection a dogma: 

He also said that they (American authorities) have been trying this for 30 years and it did not work, because the number of obese children has tripled since 2001. 

So, what does not work? Reduction of obesity or reduction of metabolic diseases with the reduced body weight? I am getting confused.

Then the slide adds two more lines: 

I have already written a short article about how the obesity can be fixed even without interfering with the biochemistry by drugs, which is Dr Lustig's field. He is a doctor after all. I am a nutritionist.

He gave an equal sign between the obesity and leptin resistance. He said that within 12 hours in an attempt to lose weight the levels of leptin are 25% lower, which he called leptin deficiency and claimed it makes things worse because on top of the leptin resistance, there is also this leptin deficiency and the brain sees it as starvation. How flawed this very simplistic picture is you can realize after reading a short article here. 

Then two more lines were added to the slide: 

Dr Lustig said that if leptin was working people would not be obese. Really? Is it the only reason for obesity? Not the palatable and caloric food that makes people eat more than they normally would? It was well documented that people feel the satiety later when eating palatable food. Other behavioral research also found that people eat more when the food is well presented food while they are socializing. 

I accept that in many diseased people fixing the metabolic dysfunction will improve their obesity. However, does this apply to everybody? Take an individual who has just started to live a comfortable life with abundance of palatable food, which will inevitably lead to increased body weight. Is his metabolism dysfunctional already or not? Yes, there are people who have very strong homeostatic mechanism for maintaining stable body weight, but others do not seem to have it as strong. Is that a metabolic dysfunction? We have evolved on laying the fat deposits when the food was abundant because it was not the case for the whole year and there were periods with reduced access to food when the stored energy was a life saver. The problem is we do not experience a true hunger anymore. But we still have the physiology of our distant ancestors. 

The doctor used to say that it is the trick of the food industry to make people eating (and buying) more of the energy dense and processed food by making it palatable and irresistible. Is that not true anymore? Or, does this apply on those who have not yet developed insulin and leptin resistance, or these were not included in the model of metabolic dysfunction? 

For now we have the official statements of many health bodies that reducing body weight of obese people cuts their risks of disease or even death. In fact, I have just found this study, which compared the metabolically healthy obese and diseased obese people. You know what? They both were at a higher risk of death whether of all causes or due to the cardiovascular disease, in contrast to overweight. How completely different from what Dr Lustig has been presenting to you.