As mentioned in the information regarding the lumens, in some cases a lamp or bulb with more power may have less lumens or "give less light" that a less powerful. This depends mainly on energy efficiency and one of the ways to differentiate from each other is through energy label. This establishes a scale from E (incandescent bulbs) to A (LED). That is the higher, more efficient, but at the time we bet by the LED efficiency is assured.
It is very important to know that today most lamps have lamp housing market that allow easily install LED bulbs. In this way the energy efficiency of the lamp will be the LED bulbs installed.