Dolphins get 40s flab, too. Duke Today, Aug. 13, 2021. If you feel like your metabolism just isn’t what it used to be, no matter how many hours you spend in the gym, dolphins can relate. A new study finds that bottlenose dolphins burn calories at a lower rate as they get older, just like we do. It’s the first time scientists have measured an age-related metabolic slowdown in another large-bodied species besides humans. Picked up by Earth.com and The Weather Channel.