Type 1 diabetes usually occurs in childhood and involves the autoimmune destruction of cells in the pancreas which produce insulin.  They produce too little insulin, while people with Type 2 DM actually produce an excess.  These people are usually not obese and will all require insulin shots to stay alive.  There is reason to believe this disease is caused by an immune reaction to wheat, and patients should be checked for other autoimmune issues such as celiac disease and hypothyroidism.

As mentioned above people with Type 2 diabetes produce lots of insulin; the problem is that their tissues are not sensitive enough to its effects.  It is their bodies' way of saying "no more!  We have too much fat already!".  These patients often have a family history of the condition and a genetic predisposition.  This falls under the "life isn't fair" principle, and these patients have to be even more careful with their lifestyle to maintain proper health.  There is also some evidence that patients with Type 2 DM have higher levels of plastics, pesticides and other petrochemicals in their bodies - but it is not clear whether this is a cause, coincidence, or a result of their condition.

Most people with Type 2 DM (and obese people in general) actually have significant nutritional deficiencies that prevent them from processing energy correctly.  Supplementing with Vitamin D, C the B vitamins; minerals like magnesium, zinc, chromium and other nutrients may be necessary to get blood sugar and metabolism back to normal.  Of course exercise is important as well (see the "Exercise" section).

The way Type 2 diabetes is treated in conventional medicine is sorely misguided and tends to make the underlying problem worse in some ways.  One of the factors that causes the formation of cardiovascular disease in diabetes (the most common cause of early death for diabetics) is the excess insulin they produce.  Therefore giving (Type 2) diabetic patients insulin and telling them to just 'cover' their blood sugar with extra insulin after dietary indiscretions will only result in more rapid weight gain and accelerated heart disease.

Insulin is a 'growth factor'.  It causes you to store energy as fat rapidly, and has other metabolic effects that make you bigger and sicker.  Patients on increasing amounts of insulin will continue getting fatter and requiring even higher doses if they don't get the right help to 'break the cycle' the correct way.  Unfortunately most of the oral medications for Type 2 DM cause weight gain as well - which is why there is NO SUBSTITUTE for proper nutrition and exercise in the treatment of this condition.

Hormone balance and heavy metals or other chemical toxicity may play crucial roles as well, posing barriers to successful weight loss.  These issues can be identified and treated effectively by a properly trained integrative physician or naturopath.