Food problems are, in part, a feature of environmental problems. Food tolerance will change with different environments - tolerance also changes seasonally. Patients in northern and temperate climates tend to be sicker in the winter. They are more exposed to indoor air quality problems, increased air pollution because of inversions, high humidity, increased consumption of fossil fuels and wood. The loss of sunlight has profound biological effects - seasonal depression and changes in immune responses are obvious effects.
People eat more in the winter and are less physically active.
Most of the patients I see report intolerance to airborne chemicals as they recover from food-related illness. DRT refers to specific strategies of correcting disease by modifying food choices, and eating behaviors. Proper diet revision must restore control over a confusing, chaotic set of circumstances and symptoms. Careful application diet revision therapy will reveal the fundamental significance of the food supply in the production of disorder. A systematic method of diet revision with full participation of the patient in evaluating and selecting foods has never before been introduced into medical practice nor dietetics.