Original thread here. (This thread earned me a spontaneous block by @lchfRD. Bless her soul.)
For people with diabetes, low-carbohydrate diets that produce similar weight loss as high-carbohydrate diets also produce similar reductions in HbA1c, a measure of blood glucose.
Caveat: Blood glucose variability might be improved on a low-carbohydrate diet, with higher fasting blood glucose but fewer glucose “spikes”. Likewise for triglycerides: LCHF tends to lower fasting triglycerides. What benefit these have is unclear.
Weight loss drives most of the improvements in T2DM. On average, there is no advantage to carbohydrate-restricted diets for weight loss when diets compared are both low in refined carbohydrate and processed foods.
Therefore: there is no clear advantage on average in terms of biomarkers to treating type 2 diabetes with a low-carbohydrate diet, except perhaps for triglycerides and glucose variability, each of which have unclear importance. The downside to LCHF of course is LDL-C.
Thus, the evidence in favor of LCHF for T2DM comes in the form of unestablished biomarkers, while the evidence against comes in the form of established biomarkers.
In other words, evidence in favor of a clear benefit does not exist while clear evidence of potential harm does.
Therefore, if this is right: while it makes sense for LCHF to be an option for type 2 diabetes in some people, it also makes sense to recommend against it, and it is understandable why scientific organizations are reluctant to endorse LCHF for type 2 diabetes.
Caveat: those with type 2 diabetes may need fewer medications when on a lower carbohydrate diet. This makes sense. Because there is lower insulin secretion on a low-carbohydrate diet to maintain the same blood glucose levels, it would make sense that less medication would be required to do the same thing.
This advantage should not be overlooked. But neither should the speculative nature of most other claimed advantages. Nor the concrete, established disadvantage of LDL.