After analysing figures from 1.1bn health examinations between 2002 and 2012, the committee said that the proportion of patients with a body mass index of 30 or over, the starting point for obesity, had grown from 2.6% at the start of the period to 4.2% a decade later.
Moreover, the proportion of severely obese patients with a BMI of 35 or over had grown by over 260% during the period.
The overall percentage of obese men was one percentage point higher than women, though in the lower income bracket, more women than men were obese, the analysis showed.
The obesity rate was highest among those in their thirties, at 5.5%, while the pace of growth was the fastest among those in their twenties, the committee said.
It also found that the risk of death for severely obese people was 1.4 times higher than that of people in the optimal weight group.