I think that there are several issues overlooked all too easily with the low fat vs low carb debate. They are worth bearing in mind.
1) One scientific study is not directly comparable to another
We place huge emphasese on scientific studies proving this, that and the other and the problem is different studies are designed differently and so it is difficult to understand their application. For example, what is low carb? In some studies it is <300g/day, in others <150g, and all the way to <~50g. These are all clearly different diets. Then comes the question of proportion of fat and protein. This will dramatically change the result. Then length of study, and many other variables not least your target participant (obese? Healthy?). It can become a mine field. Further, there is the complexity of human variability. This is why Phase I clinical trials can seem the best medicine ever and fail spectacularly in Phase III.
2) The needs of a diabetic or rather, the motivation for going low carb are very different from non-diabetics and are usually not primarily motivated by a desire to lose weight.
3) Adherence is a significant factor in a diet that studies which primarily address weight loss do not fully take into account. Some studies do try and compare this, but it is important to address this where health is a major factor and a lifestyle change can influence that.
4) The way people react to most things will fall under a bell-shaped curve. How steep or flat that curve is will be the variable. Thus some people will respond in 2 very different ways to the same stimulus and while with a large enough number, you will normally see a response that gives the most common observation, how common that is will vary.
All that being said simply means that the best evidence is self-evidence. A particular type of diet may work wonderfully well for you, but it only works ok for another, and not at all for another still. But that is variation for you. But it does not matter what any study says, if something works well for you, that is what matters the most.
Personally, a very low carb diet is best for me and with exercise I can largely eliminate novorapid and rely only on lantus. With carbs my BS is all over the place and I will get hypos from novorapid which results in a yo-yo effect which I'd probably worse for your long term health than running slightly high, but consistent.