As an infantryman and in Special Forces, we often ate in such a way due to the inability to carry enough rations for the entire mission. One meal a day is typical on many missions. I do not recommend it as a diet plan. You are training your body to store up calories more rapidly, as fat, for those times when you have no food. Yes you will lose weight, at least in the short term, but it does damage to the body. A healthy diet with everything in moderation, along with exercise, is the only healthy way to lose weight. Burn more than you take in, and eat a healthy, balanced diet.