Not and have any idea how close I am to my target deficit; I'd either err low and fail to lose the weight, or err high
and badly endanger my health via malnutrition. With the band, I know exactly where I'm coming in on a daily basis, and I can, for example, plot calorie deficit over delta-weight and see where I should be aiming for best effect.
In general, I'm surprised to see such a Luddite attitude espoused on HN. What kind of engineer doesn't see the value in collecting the necessary data to characterize a
problem or a process accurately? That's Step One.