The proposal would ban
“Certain medical conditions — including, but not limited to, cardiovascular diseases, respiratory diseases, cancers, diabetes, metabolic diseases [being overweight], neurological diseases, and mental health conditions ” – which includes banning those who are “overweight”.
The proposal says applicants can be rejected because of their age, or if they have high blood pressure, or asthma.
Over 70% of the world’s population over the age of 40, 85% over the age of 60, and 90% over the age of 65 have at least one of the above conditions and would be excluded from receiving a long stay visa in the United States. Some people have multiple conditions so you should not add these percentages together:

These restrictions would also apply to their dependents – so if a child was overweight, they could not legally immigrate to the U.S. The proposal also says immigration offers should make their own determinations about applicants’ fitness, even though immigration officers have no training in medical conditions.
The effect of the proposal would be to ban most adults over the age of 40 from legally immigrating to the U.S. – or apparently even receiving a long stay visa. There might be an exception for those who can prove to have adequate financial resources to purchase adequate insurance and/or pay for their own medical care – which implies the wealthy may be exempt.
As someone who has had more than one traumatic brain injury (skull fracture), and who has a heart condition (treated and completely stable), I would be banned from the United States.
Do other countries have these restrictions? If not, will then develop their own reciprocal restrictions so that U.S. citizens would be restricted from long term stays in other countries?
If so, the door for persons over the age of 40 thinking of moving to another country – or even a temporary longer term stay over 90 days – may have come to an end. Only the young and healthy will have an opportunity to develop global skills and experience other cultures directly.