The effect of a low-carbohydrate high-fat breakfast on glycemic control in type 2 diabetes

Improving overall glycemia by targeting postprandial glucose spikes, particularly at the breakfast meal when insulin resistance is the highest in type 2 diabetes (T2D), may help to prevent diabetes complications. The purpose of this thesis was to determine whether consuming a low- carbohydrate high-fat breakfast was superior to a breakfast with the dietary guidelines recommended nutrient profile for improving postprandial and 24-hour blood glucose responses to mixed meals in individuals with T2D. Adults with physician diagnosed T2D (N=23, 59 ± 11y, A1c: 6.7 ± 0.6%, BMI: 31 ± 7kg/m2) completed two 24-h isocaloric intervention periods, in a random order. Participants consumed either i) a low-carbohydrate high-fat breakfast [LC-BF; <10% energy from carbohydrate (CHO), 85% energy from fat (FAT), and 15% energy from protein (PRO)], or ii) a breakfast with the dietary guidelines recommended nutrient profile (GL- BF; 55%CHO/30%FAT/15%PRO), with the same lunch and dinner provided (both 55%CHO/30%FAT/15%PRO). Continuous glucose monitoring assessed postprandial glucose responses to each meal (incremental area under the curve; iAUC) and the mean 24-h glucose during each intervention. The postprandial glucose excursion (3h iAUC) after the LC-BF was ~80% lower than the GL-BF (p<0.01). Overall postprandial hyperglycemia (measured as the sum of the 3h iAUC of breakfast, lunch and dinner), and glycemic variability (mean amplitude of glycemic excursions [MAGE]) were significantly reduced with the LC-BF compared to the GL- BF (3h iAUC: -100 ± 116 mmol/L•9h, p