There is a YouTube video about an experiment with gum and helium, creating a balloon that can lift a person.
Using the law of hydrostatics, the driving force must be at least equal (as can be seen in a certain part of the video) to the weight of the man with the balloon..
P = I
Replacing the weights by m g and knowing that
The mass of the man will be
Substituting the values
and we can drawing the graph mH = mH(R)
We have, for a mass exceeding 65 kg, the diameter of the balloon will be greater than 5 m.Therefore, by observing the video, is not the case.
The person has a high less than 2 m, the diameter of the ballon is much less than 2 m.