He takes too much grease, and it's not normal for a high level sportive. Everybody has got a different metabolism. Some people never does sport and takes 0 gramme. Others can run 10 km each week and takes 2 or 3 kilos rapidly even with a normal nutrition. The solution for those people (like Sakho) is a nutritionist, not "miracle" products ...
Precisely.
I have made an effort to comprehend the psychological mechanisms why such players use metabolic chancing substances and put their career at risk. Not to mention risk their health.
As an adult, playing for Liverpool, high payed footballer, it probably isn't just a matter of a nutritionists advision. Or at least, it didn't felt like that for him. I don't know, but one believe that he had encountered several nutritionists at that level of career.
He much have suffered from somewhat metabolic issue from a very young age, which has caused him so much emotional distress that an illegal substance seemed to be the solution. He could have felt several things about it, but most likely ended up that it was his only way dealing with it.
Always some hidden feelings about the way one eat and the connection to food - and not always dealt with, with logic or hindsight.
Some of the same mechanisms in the sport of cycling - and maybe, even more amplified as the optimized physics are even more important in this sport.