We are very, very focused on diet and nutrition. My early training was in Nutritional Medicine, which is really the therapeutic application of nutrients in place of drug therapy. It is not the same as the nutrition learned by dieticians.
What is very clear to any practitioner who was dealt with chronic fatigue syndrome or complex and chronic illnesses is that the gastrointestinal tract is almost always a player in the process, and the successful management of gut symptoms and restoration of normal gut function is one of the cornerstones of almost every successful treatment outcome.
Different people need different type of food, but almost everyone benefits when the diet consists of fresh organic foods in season with high variety and high nutritional content, especially the trace elements and omega-3 fats found in fish.
Of course, this isn't the case for everyone, especially those requiring highly restrictive diets.
One of the jobs natural healthcare practitioners do repeatedly and well is to restrict diets to improve the health of people affected by adverse food reactions. What is equally important, however, is to restrict only those foods with solid evidence of adverse reactions, and to reintroduce all the foods necessary for optimal nutrition and to restore the joy of eating and sharing meals with one's family.
I do restrict certain foods such as gluten and milk with the person's history or family history, or functional or genetic tests point to a food-related disorder. During this time, nutritional supplements are often helpful in maintaining a high quality of nutrition prior to the reintroduction of the foods.
As described under Genetics previously some people carry genes that predispose them to fight prolamins in gluten-containing grains such as wheat, rye and barley. One rare outcome of this is coeliac disease, but the more common outcome is autoimmune disorders such as thyroiditis, type II diabetes and chronic inflammatory disorders.
I am not a fan of prolonged restricted diets especially severe restriction of healthy foods such as fruit and vegetables in low-salicylate diets. In most cases, if the diet needs to be restricted it is because the gut is abnormal, inflamed and possibly leaky,
I use probiotics and cultured foods such as kefir, yoghurt, sauerkraut and others along with short-term, specific dietary restrictions to restore gut integrity, decrease gut permeability and return the sufferer to normal joyful eating and better nutrition.