Walking is a venture that is one of the built-in features of the average human container.
It is often practical, pleasurable and metaphorical (walking the talk, cake walk, walking the line).
In the context of a healthy lifestyle, it is often overlooked as a superb component and bucks the trend of the "As seen on TV" range of useless gadgets, which should be prefaced by "If seen on TV, run, nay, walk away, flee like a gazelle, nay walk away briskly like a bipedal organism".
By the speedometer, walking at a sedate 4km/hour will burn you 210 calories, which will totally and happily negate the 1.425kg of celery you had guiltily scarfed down earlier on. Of course that is assuming all calories are equal once consumed, and Robert Lustig convincingly argues against the energy in/out concept, whereas the world's leading soft drink manufacturer argues for the in/out concept, as that then places their produce as one of the treat variables in a "healthy balanced diet". Yes, I agree, that is another story.
Pick up the pace to Bill Charnock velocity (local walking legend), which might be 10km per hour or more, and you expend 740 calories, which mitigates the deleterious effects of eating which is apparently a Carl's Junior Chocolate shake according to acaloriecounter.com.
Loading during walking is of importance to the pedantic, the biomechanics boffin, the injured and the arthritic. In a study in the journal of biomechanics, it was observed that the loading on the hip joint was 2.8 times body weight at 1km/hr, rising up to 4.8 times body weight at 5km/hr. Interesting trivia, but a strong muscled body is well equipped to deal with these loads. If it isn't, strengthening the muscles will bring you back towards optimal. Interestingly they were also able to document the load of stumbling, which may have been either opportunistic or else they studied a population of inebriated university students. Stumbling caused a load of 7.2 times body weight. This then allows the reader to draw the conclusion that the Saturday/Sunday morning walk of shame carries a greater risk to the delicate hip joint structures.