Our contribution to illness is only one factor out of many. Illnesses do not arise only through internal causes. There are outer causes too—causes that are not only physical and psychological, but also subtle and occult.
Perhaps the best advice is to eat in moderation, without greed, at regular times, a tastefully balanced diet with all the essential nutrients prepared hygienically and above all, to offer it to God and receive it as prasada. This would be the best diet.
There is increasing evidence that we have a great role to play in the healing process, in both minor and major disorders.
Most illnesses (nearly 90%) are self-healing by nature and the system of therapy used really does not matter. Still others can be corrected by lifestyle adjustments, such as diabetes. Out of the other 10%, about 8-9 out of 10 again, are largely contained rather than cured. It is only the 1% where the choice of system makes a sizeable difference.
Different systems do not necessarily speak of different causes but they do speak from different levels, or may use different language. What we need to understand is that each system probes and understands man and his maladies at different levels of existence. They do not contradict but often complement each other.