Is Orthodox fasting a diet?
Fasting is not about health or weight, and it is easily spoiled. The Lord warns against the fast put on for others to see: when you fast, do not look gloomy; wash your face, He says, and let it be a secret between you and God. Pride in fasting undoes the whole good of it.
And the surest sign that a fast has gone wrong is that it makes us harsh, measuring others' plates, priding ourselves on our strictness. Keep your eyes on your own table and your own heart. A little fasting kept in humility and love is worth far more than a great fast kept in vanity or judgment.