Part of the reason is the beneficial effect the fish oil has
in keeping things moving, beneficially affecting digestion and
metabolism. A piece
of white bread isn't all that high in calories, but it metabolizes so quickly into sugar it's very hard for an average person to burn it off before it stores as fat. Focusing on calories hasn't worked all that well over all the years of advertised diets, because it doesn't factor in individual metabolism. Peace.