Managing the obesity of 10 billion people by 2050 may be achievable.
The biggest obstacle is that there won’t be 10 billion people in 2050. Due to the crashing population growth rates, and reduced statistical fertility in all corners of the globe, we’ll be lucky to even reach 9 billion by 2050. I’ve already mentioned by contraceptive-ban and Barry White policy in another thread so I won’t go over that again.
The amount of food produced per capita in the globe has grown at an alarming, almost ridiculous, rate. In 1961, there were 9188 kJ of food produced per person in the world.
There is now more than 12000 kJ of food produced per person in the world.

There’s currently enough food produced not just to feed that 9 billion people, but (allowing for global average height) to make 9 billion people obese.
Politicians don’t seem to be prepared to deal with 9 billion people with high incidence of type 2 diabetes, heart disease, inability to fit into MRI scanners, crumbling joints, and high blood pressure. They are sleepwalking into a medical crunch.