exactly pomhat - the easiest calories to lose, are those that you do not consume in the first place.
the video "the mathematics of weight loss" - shows the amount of sugar in a 600ml soft drink - that sugar is simply added to some water, with a bit of flavouring - and totally unnecessary to consume - yep 17 teaspoons of sugar in the drink
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in other words, to compensate for the sugar in that one 600ml of soft drink, a person needs to walk for about an hour. frankly, it is easier, and more pleasant to drink a glass of water, and be a couch potato - watching the football