A June 2024 study by University College London said

  • “Several health companies are now using CGMs as part of paid-for programmes designed to give people personalised nutrition information.”

  • “Some claim to tailor a person’s diet and activity to help keep blood glucose within ‘normal’ levels. But what constitutes a normal blood sugar level varies between individuals and in the same individuals at different times, and CGM accuracy varies between CGM models.

  • “With this in mind, we wanted to see what research had been undertaken into the use of CGMs in people who do not have diabetes.”

  • “This review unpicks the idea of ‘abnormal glucose’, the accuracy of CGM data, and the effect on behavioural change when CGMs are used by people without diabetes.”

  • “At the moment there are big questions about how much guidance these health companies are giving customers to help them interpret their glucose data, and what scientific evidence this guidance is based on. This can leave the customer to interpret what the variations in their blood glucose mean, posing a risk that they misinterpret the data and avoid certain foods unnecessarily.”

  • “However, the regulations for CGMs for people living with diabetes are ambiguous both nationally and internationally, making it difficult to know if available CGMs meet this level of accuracy. This is why the IFCC CGM group are pushing for an international standard.”

  • “For individuals not living with diabetes, the situation is even more uncertain. We have little robust information on whether CGMs achieve the required accuracy in this population.”

  • “Normal glucose levels for individuals without diabetes range from 3.3 to 7.8 mmol/L and the most accurate CGMs have a 20% accuracy margin most of the time. This means that the most accurate CGM devices will display readings between 2.6 and 9.4 mmol/L, even when the actual glucose level is within the normal range. Such discrepancies can lead to unintended stress and potential psychological and behavioural implications.”

  • “While CGMs for people not living with diabetes show promise, the accuracy, regulatory standards, and psychological impacts of false highs and lows are not well understood. Despite this, CGMs are being heavily promoted without mention of these issues.”