Impact of high-fat /low-carbohydrate, high-, low-glycaemic index or low-caloric meals on glucose regulation during aerobic exercise in Type 2 diabetes.
OBJECTIVE
A decrement in blood glucose (BG) may be observed in patients with Type 2 diabetes (T2DM) when exercise is performed after a meal, in contrast to fasting. We determined the impact of different pre-exercise meal macronutrient compositions with modulation of the glycaemic index (GI) on glucose regulation during exercise in patients with T2DM.


METHODS
Using a randomized, single-blind crossover design, 10 sedentary men performed five exercise sessions, once after an overnight fast, and also after each of four test meals, consisting of a high-fat/low-carbohydrate meal, a high-GI meal, a low-GI meal, and a low-calorie meal.


RESULTS
Pre-exercise BG and insulin levels were comparable for all four meals. Exercise decreased BG and insulin levels during all meal conditions (all P < 0.001) compared with the fasting state in which BG levels did not change. The magnitude of BG and insulin decrements was similar after consuming the low-calorie, the high-GI and the high-fat/low-carbohydrate meals, whereas the low-GI meal induced the lowest BG fall. Adrenaline response was higher after consumption of the high-, the low-GI and the low-caloric meals compared with the high-fat/low-carbohydrate meal and with the fasting state (P < 0.05).


CONCLUSIONS
This study underlines the beneficial effect of low-GI foods and the differential impact of pre-exercise meal macronutrient composition on BG decrease. This may protect against exercise-induced hypoglycaemia, and reiterates the safety of exercising while fasting in T2DM patients.
Ferland
A
A
Laval Hospital Research Centre, Quebec Heart and Lung Institute.
Brassard
P
P
Lemieux
S
S
Bergeron
J
J
Bogaty
P
P
Bertrand
F
F
Simard
S
S
Poirier
P
P
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D004040:Dietary Carbohydrates; D004837:Epinephrine / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005215:Fasting; D038321:Glycemic Index / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin; D004837:Epinephrine