Is the Low Carb diet approach for Type 2 Diabetes Management truly evidence based?
New statement document from Public Health England on the clinical effectiveness of low carb diets in the Type 2 Diabetes population. ie what can be proven by clinical trials.
Have a read and see what you think?
The reason for sharing is that I think we should ALL implement the form of low carb diet that suits our preferences, and not feel pushed into any form of specific carb counting or limiting per meal or per day.
My take on this document is that is very hard to confirm what really constitutes a low carb diet and whether it is manageable by the individual ie there is no science that confirms that it is the only approach that works.
Overall, the evidence suggests beneficial effects of lower carbohydrate diets on HbA1c, fasting plasma glucose and serum triacylglycerol in the shorter term (up to 6 months).
Although there was no consistent evidence of reductions in body weight with lower carbohydrate diets, it is not possible from the evidence considered to separate the effects of weight change from effects of change in carbohydrate intake. Lower carbohydrate diets may allow reductions in diabetes medication, but interpretation is complicated by inconsistencies in reporting and measurement of changes in medication use.
No differences were observed between higher and lower carbohydrate diets on serum total cholesterol or LDL cholesterol either in the shorter (≥3 to 6 months) or longer (≥12 months) term. Evidence on HDL cholesterol was inconsistent in the shorter (≥3 to 6 months) and longer (≥12 months) term.
It is not known if the reported effects of lower carbohydrate diets apply to individuals of different ethnicities since the majority of primary RCTs did not report ethnicity of participants and were conducted in populations that were predominantly White.
The following gaps were identified in the evidence base and these informed the research recommendations.
• effects of lower carbohydrate diets on individuals living with T2D from minority ethnic population groups was not considered
• no trials provided information about types of carbohydrate consumed (for example, wholegrain, refined grain, free sugars, fibre) or considered how this could affect the outcomes of interest
• the potential impact of increasing the proportions of other macronutrients (fats and/or proteins) to compensate for reduced carbohydrate intake in the lower carbohydrate groups, or the type of macronutrient (for example, saturated or unsaturated fats; plant or animal-based proteins), on markers and clinical outcomes of T2D was generally not considered
• few trials assessed adherence to dietary interventions throughout the study duration or considered how adherence might impact the outcomes
• few trials assessed longer-term effects (beyond 12 months) of lower carbohydrate diets
• no trials considered clinical endpoints such as diabetes complications, cardiovascular disease (CVD) events or mortality.