Weight regulation is not a simple matter of "calories in, calories out". Sugar causes obesity disproportionate to its calories, and (surprisingly) no-calorie sweeteners actually cause weight gain. How can you gain weight from something with no calories? The body learns to associate the taste of a food with how much energy it gives. When sweet taste becomes associated with zero calories: (1) people’s metabolisms slow, (2) they eat more – and since their metabolisms are slowed, they gain more from what they eat.
That’s bad enough, but no-calorie sweeteners – even stevia – may contain other serious health risks. This article cuts through the complacency and hyperbole to give you the facts.