Two lawmakers said that the agency announced this during a closed parliament session, and added that intelligence officials used artificial intelligence techniques, high-definition video analysis, as well as other methods to verify Kim’s status.
Kim’s health has received great outside attention in the past months, as he appeared noticeably thinner in photos and videos broadcast by the official North Korean media.
Kim, 37, has not yet named a successor, and experts say his sudden death could cause chaos in the impoverished, nuclear-armed nation.
Despite Kim’s slim appearance, observers have said that Kim does not have obvious health problems, and that his weight loss may be a result of his efforts to improve his physique.
They noted that he continued his usual public activities, and no unusual developments appeared in the videos.
Rep. Kim Byung-ki said the National Intelligence Agency had told parliament that Kim’s weight had dropped from about 140 kilograms to 120 kilograms.
The agency had previously said that Kim was about 170 centimeters tall.
It added that Kim has participated in public activities for 70 days so far this year, up 45 percent from the same period last year.