The answer will vary from one country to another. Comparable and comprehensive global statistics are not available.
The percentage of adults who are obese in Canada is 23.1 %. (BMI is over 30)
It is not always easy. Sometimes the context can help. Also, if the reference is to a fraction where that makes no sense, it is likely to be a percentage. For example, consider the statement "27.2 adults in the US are obese". Clearly, it cannot be 27 adults and a fifth of one so the 27.2 must refer to either a percentage of the adult population or some scaling unit such as 27.2 thousand or 27.2 million.
4/5 adults 1/5 child
Approximately 1.7% of U.S. adults are underweight.
2 - 3 percent of adults sleepwalk occasionally
They were considered adults when they started developing which was around 13 years old.
55.25% to be exact!
77.7%
Kids are considered adults when they reach 18, which is the age of majority in most countries.
About 20% of adults worldwide have never had sex.
15 percent
42/59%