This process of errors is cumulative, says Bates, and may begin in infancy. Signs of IMED are apparent in babies who have feeding problems, colic or some kind of chronic indigestion, diarrhea, allergies, eczema and an inability to tolerate certain foods such as cow's milk. Later they may show a tendency towards chronic bronchitis and middle ear infections.

In school they may have learning disabilities or hyperactive behaviour. The process takes its toll over the years. By adulthood there may be more complaints: irritability, joint pain, noticeable fatigue, depression and migraines, gastritis, ulcers and heartburn. Any chronic inflammatory disease of the upper or lower gastrointestinal tract is a significant sign.

Bates' theory sits well with the inroads made into the link between blood type and diet. The theory goes that dietary lecithins can trigger different allergic responses in different individuals, depending on their blood type (J Nutri Med, 1991; 2: 45-64; Am J Clin Nutri, 1980; 33: 2338-45; see also D'Adamo, J, One Man's Food is Someone Else's Poison, Marek, 1980). If food lecithins pass undigested into the gastrointestinal tract, they are either recognized as self or non self by the body's immune system. Cooking eliminates a large percentage of dietary lecithins, but not all. Some, such as those present in wheat, tomato, carrot, corn, banana, peanuts, pumpkin seeds and avocado, are highly heat resistant.

Although not specifically centred around obesity, the research into serotyping and diet shows that certain blood groups react badly to certain types of foods, resulting in allergies, inflammation and leaky gut as well as wasting diseases such as Crohn's disease (Townsend letter for Docs, Nov 1996: 74-7).

Another theory is that, for a variety of reasons we wrongly interpret our body's needs. Dr. Fereydoon Batmanghelidj, author of Your Body's Many Cries for Water (Global Health Solutions, 1994) believes that many common illnesses today are the result of a profound kind of dehydration. Infants recognize thirst and cry out when they need liquid. But, he says, as we grow older we become unused to drinking water, and gradually the thirst signals are misinterpreted or over ridden. As they grow up, children learn to drink sodas, colas and juices instead of simple water. Adults respond to the body's thirst with tea, coffee and alcohol all of which dehydrate the body further (Independent, January 11, 1994. The body then responds by releasing more anti diuretic hormone, and a vicious cycle is instigated.

If food sensitivity and/or dehydration theories are correct, obesity could be seen as not just excess fat, but a kind of waterlogging which occurs as the body tries to restore balance.

!APat Thomas