Key points from article :
Twenty people gave up a month of their time to live in a laboratory.
Volunteers had every bite of food they ate monitored for a month.
They were given either ultra-processed meals or unprocessed ones and then the diets were switched.
Volunteers ate 500 calories a day more compared to when they were given unprocessed meals.
The US National Institutes of Health said ultra-processed foods may be affecting hunger hormones.
