So can you be Low Fat and reverse diabetes? The standard propoganda from the Low Carb crowd goes something like this:
"Of course not! A Low Fat Diet is a high carb diet and carbohydrates will always raise blood sugar and make diabetes worse."
The logic here may seem sound to some, but, as is so often the case, the human body often operates counterinuitively. First of all, what really affects insulin sensitivity is, surprisingly, a high fat diet. So, generally speaking, someone eating a Low Carb Diet will have to consume very high fat levels in order to get enough calories during their maintenance phase. If this happens, insulin resistance is often induced. In fact, this property of Low Carb Diets is used all the time with lab animals: researchers will put animals on a high fat diet in order to study insulin resistance and, unfortunately, humans are no different.
Now it is true that if someone cheats and eats a Low Fat Diet with a bunch of refined carbs and high glycemic foods, he is bound to get into trouble. Cheaters never win, eh? However, there is a Low Fat researcher who has shown something remarkable: you can actually reverse diabetes with a Low Fat Diet!
What is the secret? It is very simple: you simply eat low fat and low glycemic at the same time. This is not as hard as it sounds as many low fat foods are low glycemic, such as beans, legumes, vegetables, many fruits, etc. We'll discuss this a bit more below but think of the significance of this for many middle-aged and senior men: they can likely reverse their diabetes and partially reverse their arteriosclerosis at the same time. This is a chance to actually get their life back.
And one other huge benefit of going on this type of diet: easy weight loss! Most men will steadily (and effortlessly) lose weight on a Low Fat Diet initially. The reason is simply: starchy foods are generally bulky, low fat, high fiber foods that fill you up. These kind of foods are low calorie simply because a carb is only 4 calories per gram whereas fat is 9 calories per gram.
I get men writing in and asking, "How can I get enough calories on a Low Fat Diet?" The issue with a Low Fat Diet is actually NOT to lose weight. My answer, by the way, is to add some supplemental protein. In my case, I add in undenatured whey, egg whites and rice proteins to round out my diet. And, practically speaking, most clinicians would agree that anything below 7% is a reversal of diabetes. If you have more questions, please visit the Peak Testosterone Forum.
Most men who have arrived at the stage of Type II (adult onset) diabetes have gotten there slowly over time, having passed long ago throught the prediabetic stage. During this long and unhealthy transition period, significant damage to their cardiovascular and endothelial systems has ensued, leaving them (very likely) with a substantial buildup of arterial plaque. With one simply dietary regimen, they can very likely get their life back and reverse both conditions.
NOTE: Of course, if you are diabetic or on medications, you need to work with your doctor as an lifestyle change can modify the need for medication which alter blood sugar levels.
A great guidebook on the mechanics of doing this is Dr. Neal Barnard's Program for Reversing Diabetes. Dr. Bernard has done a number of classic studies on Low Fat diets in diabetics and found that:
1) Insulin sensitivity improved by 24% in 14 weeks. 
2) A1C was reduced from 8.0 to 6.8 in 22 weeks.  A1C is a marker called "glycated hemoglobin" that essentially measures your average blood glucose over the last three months.
Now some may object that, according to the 2009 standards set up by the International Expert Committee of the American Diabetes Association, an A1C of 6.5% is technically the official marker of diabetes.  Their reasoning was that at this level, diabetes complications such as retinopathy are quite uncommon. However, Bernard's achievements of lowering down to 6.8% in just a few months is remarkable.
Futhermore, with additions such as weight loss, exercise and possibly HRT (for low testosterone men) going below 6.5 could often be achieved. One example of this is a study that combined a low fat, high fiber, high complex carbohydrate along with exercise and found that "this decrease in fasting glucose was achieved along with the discontinuation of oral hypoglycemic agents in 24 of 31 patients and of insulin in 13 of 18 patients;." 
NOTE:: Low testosterone greatly increases the risk for developing diabetes, because it raises insulin levels and eventually reduces insulin sensitivity. Furthermore, many men with Type II diabetes can actually completely eliminate their need for insulin with properly done HRT. See my links on Testosterone and Diabetes and Testosterone and Insulin.
These men also very likely experienced many other key aspects of going on a Low Fat Diet, including a) increased blood flow, b) increased nitric oxide and c) decreased blood pressure. Of course, all of these are good for erectile strength and you can read more here in my link on The Many Benefits of Low Fat Diets.
Again, though, the key is that one must eat low glycemic foods. For those who may not be familiar with the term, the glycemic level of food is simply a score as to how much a given food raises blood sugar levels for a given weight of food. Of course, refined carbs will almost always elevate your blood sugar rapidly. There are many foods which are low fat, cheaps carbs and sugars for example, that will do just this. Again, though, this is NOT the spirit of a whole foods, high fiber, Low Fat Diet.
And it's not that hard. For some of the details check out Dr. Bernard's book above. The books by Drs. Ornish and Esselstyn are also excellent.
One last recommendation: get yourself an inexpensive blood glucose monitor if you do not have one. You want to watch to make sure that your blood glucose levels do not rise too rapidly after a meal and this is an relatively inexpensive way to do some self-monitoring. (If you are diabetic, please follow your doctor's monitoring instructions of course.)
CAUTIONS: There are many ways to do a Low Fat Diet. Dr. Bernard's methodology outlined in this book includes both soy and wheat. Personally, I am very cuatious about both for the reasons outlined here in my links on Soy and Men and a Review of Wheat Belly.
1) Dr. Neil Bernard's Program for Reversing Diabetes, Neil Bernard, p. 19-20.
2) Diabetes Care, 2009 July; 32(7): 1327 1334, "International Expert Committee Report on the Role of the A1C Assay in the Diagnosis of Diabetes"
3) Diabetes Care, May/June 1983, 6(3):268-273, "Long-Term Use of a High-Complex-Carbohydrate, High-Fiber, Low-Fat Diet and Exercise in the Treatment of NIDDM Patients"