Single Mediterranean meal study shows low carb diet still best for blood glucose control

Research into the effects of a single Mediterranean meal against two low carb or low fat meals show promise for the single Mediterranean meal but, ultimately, the low carb meals produced better blood glucose control.
Researchers from Linkoping University in Sweden have tried a variation on the practice of comparing three different diets. Rather than keeping the same number of meals in the study, the researchers looked at comparing a low fat breakfast and lunch against a low carb breakfast and lunch against a single Mediterranean lunch.
The rationale behind this comparison is that, traditionally, a Mediterranean diet has not included breakfast. In comparing the diets, the researchers ensured the energy composition of the diets was closely matched. In terms of carbohydrate content, the low fat diet was around 50% of energy from carbohydrate, the low carb diet was around 20% of energy from carbs. The Mediterranean diet had around 33% of energy from carbohydrate.
Researchers analysed the effects of the meals on blood glucose, triglyceride and cholesterol levels and also the effects on a number of key hormones including insulin, leptin and glucose-dependent insulinotropic polypeptide (GIP). As these values can fluctuate through the day, the researchers measured the area under the curve (AUC) which adds up the overall effect through the day.
The results show that when it came to maintaining blood glucose levels, the two low carb meals fared slightly better than a single Mediterranean meal and significantly better than two low fat meals. For triglyceride levels, the low fat diet came out tops. This should not be surprising for the researchers as both glucose and triglycerides are available to provide energy for the body and as the energy content of each diet were matched, you’d expect a decrease in blood glucose to be compensated with a raise in triglycerides at least over a short space of time (several hours) as in this study.
People with type 2 diabetes should take note the low carbohydrate meals produced better blood glucose results than the other two diets. In addition, the low carbohydrate meals produced the most consistent blood sugar levels.
The low fat group had a peak in blood glucose levels of over 12 mmol/l after breakfast and a peak of over 11.5 mmol/l after lunch. The Mediterranean diet group had reduced blood glucose levels after their breakfast which consisted of just a coffee, whereas lunch saw a peak of above 11 mool/l. The low carb group saw an initial peak at breakfast of over 10 mmol/l but an after lunch peak of around 8.5 mmol/l.
In terms of cholesterol levels (HDL and LDL), the three diets were largely matched with those in the low carb group showing the best overall results. In terms of levels of insulin, of participants, the low carb diet produced, by far, the lowest levels of insulin with the low fat diet producing the highest insulin levels, at a level slightly higher than the Mediterranean diet.
The results show that a low fat diet is not an effective diet for maintaining good control of blood glucose levels, at least over the short term. The low carbohydrate diet in this study produced the best blood glucose results and with the single Mediterranean diet coming in second. Achieving good blood glucose control has been shown to be the best way of reducing the chance of suffering diabetes complications later in life.