The new rules apparently do not apply to those the officers are protecting.
Saudi Royal Guard officers have been ordered to slim down to receive their promotions and avoid punitive action.
Under an order from King Abdullah Bin Abdul Aziz, the officers have been given three months to shrink their waist to the ideal sizes endorsed in the military, local Arabic daily Al Sharq reported on Wednesday.
Officers who fail to lose weight and to shape up will face punitive measures that include losing their right to promotion.
Saudi criteria to join the military service include a minimum height of 175 centimetres and a weight that is in proportion to the height.
King Abdullah has been pushing since he assumed power in 2005 for sweeping positive changes and reforms in several sectors in the Saudi kingdom.