Principles of Low Carb in Type 1 Diabetes.
(This is aimed at Healthcare professionals but is readable for all)
There is nothing complicated about a low carb healthy fat diet in Type 1 diabetes.
People with Type 1 diabetes find that reducing carbohydrate in their diet makes control very smooth and feel that it is a safe way of managing their condition. Because they get results on day one, they are often strongly motivated to continue.
There are some necessary skills needed to manage low carb well, but these should already be known to all Type 1’s as part of their education and ongoing support.
Firstly it is essential to get the basal dose of insulin accurate so that normal glycaemia is achieved throughout fasting periods.
Next, it is a crucial requirement to understand carbohydrate counting and insulin carb ratios. All T1 should know this, but some may need a refresher.
Of course, if the carbohydrate level is a tenth of the recommended national guidelines ( most people suggest 30g of carbohydrate in Type 1 compared to 250-300 in the national guideline diet), then only one 10th of bolus insulin is needed.
Adjusting for protein. This becomes significant when carbohydrate is drastically reduced. There is a module on protein in this series.
Also, It is essential to understand how much 1 unit of insulin lowers blood glucose. This can be easily done during a fasting period as long as the fasting level is 6mmol/l or above. For most people, it is 2-3 mmol/l.
And finally, because of insulin resistance issues in those who have had diabetes for several years, it is essential to know how long it takes for the insulin to start acting. For some people can take 1-2 hours before their insulin starts to respond, so a period of intensive blood glucose monitoring after a unit or two of insulin will help identify the initial dip of glucose as the insulin starts to act. Then obviously rescue this with glucose as needed.
Once patients understand the principle, the transition is relatively smooth. Small doses of insulin lead to less dramatic swings of blood glucose, and the risk of hypoglycemia is minimised. As long as the basal insulin dose is correct, it is highly unlikely that the patient will ever get into ketoacidosis. They will, though, because of the nature of low carbohydrate healthy fat diet, be metabolising fat and producing ketones, which will appear in the blood and urine at higher levels than most healthcare practitioners are used to. Blood levels of 0.3-3.0mmol/lit are typical in LCHF. 3+ ketones in urine testing are not unusual though this tends to reduce after a few months on a ketogenic diet. With normoglycaemia, this is normal and is called nutritional ketosis.