Is this a good daily diet for weight loss?

your lunch needs to be more balanced, melons are like 90% water so they are not very beneficial in terms of nutrition esp if thats what you rely on to get through several hours. You need some complex carbs (pasta/rice/wholemeal bread/pitta etc) and some lean protein (tuna/chicken/turkey) and either veg or salad. you should have the melon as a snack around mid-morning. You won't lose weight by going to extremes cos your body will be starved and just store everything you eat as fat so you are basically defeating the purpose.