Adverse effects of food constituents

Any of the major food constituents (protein, carbohydrate, fat, mineral, vitamin, fibre, water) can induce adverse effects if they are not balanced for the requirements of the consumer. If the constituents are not balanced, the food may be avoided or, if it is the sole food available, intake will be low. One example is fibre which, being indigestible or only slowly digested (by microbes in the digestive tract), imposes physical work on the digestive tract as well as limiting the capacity to eat food. Other examples are specific plant toxins that interfere with metabolism, reducing the overall satisfaction the animal derives from each unit of food eaten. Many plants have evolved these to avoid being eaten. Another way in which food can have adverse effects is by the heat produced by its ingestion, digestion and metabolism, especially in a hot environment in which this extra heat is difficult to lose. A diet excessively high in protein can have such adverse effects due to the heat produced in the deamination of the excess amino acids. Excessive concentrations of individual minerals, particularly in plants that accumulate the minerals as a means of protection, can induce specific toxicity symptoms or adverse effects by disturbing the mineral balance. Plants with a high water content, such as young herbage, may adversely effect the intake of dry matter, particularly if requirements are high and intake capacity is limited.