Comparing snacking to total fasting in basal rate tests

This study compared the effects of low-carbohydrate snacking and total fasting during basal rate testing in people with type 1 diabetes (T1D). It was determined that there was no effect on blood glucose levels or hypoglycemia (dangerously low blood glucose), but patients preferred snacking.

Insulin is the hormone needed to lower blood glucose levels. Basal insulin helps to keep glucose levels steady between meals. Different people need different doses of basal insulin. The amount needed may be determined by basal rate testing. During a basal rate test the patient usually fasts for 24 hours while blood glucose levels are measured. These tests are not popular with patients with T1D. Thus, alternatives to 24 hour fasting, such as shorter fasting periods or light snacking, have been suggested. 

This study investigated whether low-carbohydrate and low-calorie snacking would affect glucose levels during basal rate tests. 20 adults with T1D completed two basal rate tests each. During one test patients took low-calorie, low-carbohydrate snacks (such as salad and vegetables) at normal meal times. During the other test patients fasted and did not consume carbohydrates. All patients did both tests in a random order. 10 blood samples were taken over 24 hours to measure blood glucose levels. The participants completed questionnaires about hunger, thirst, and well-being during and after both tests.

The study did not find major differences between blood glucose levels during either test. The number of hypoglycemic episodes was also similar for both tests. Patients who were allowed snacks were less likely to report wanting to stop the test.

The study concluded that light snacking at meal times did not significantly affect the results basal rate tests, and patients preferred being able to snack.

This study examined only 20 patients for a short time period. They also did not measure fatty acids or other hormones that affect blood glucose levels (e.g. growth hormone).

Discuss alternatives to 24 hour fasting with your physician if you need basal rate testing.