It depends. Focusing on calories is not the only requirement for weight loss. Foods have other characteristics that contribute to weight gain. Processed foods cause more weight gain than non-processed foods even when calories are equivalent because they are stored as glycogen which contains more water. This may explain the extra weight gain after a "rich" meal.
Bmr. Need your baseline metabolic rate (BMR) then you either eat 200-300 calories lower than your BMR or add activity that would equal 200-300 calories to keep your same diet pattern.