White and green asparagus contain 90 per cent water, proteins, a few carbohydrates and fats, and only 150 calories per kilogram. Nevertheless, the vegetable is not lacking in minerals such as potassium, which has a correspondingly positive effect on the nervous system and blood pressure. Remember the considerable amount of calcium and phosphorus. Eating asparagus stimulates kidney activity and therefore has a diuretic effect. However, anyone with kidney problems should avoid asparagus.