Many Metabolic Balance clients have little or no tomato listed on their personal nutrition plans. There are a few different reasons why this might be the case. First, tomatoes naturally contain glutamate and other fruit acids which have an appetizing effect. Secondly, tomatoes contain oxalic acid (similar to rhubarb, beetroot and spinach). This is known to bind to calcium, and thus, it reduces the availability of calcium for absorption and hence for the body to use. People suffering from gout, rheumatism and with histamine intolerance are advised to avoid tomatoes, or at least eat them only occasionally.