What is the Second-Meal-Effect?

What is the Second-Meal-Effect?

Hello everyone!

In today’s blog post we look at the increase in blood sugar levels after eating various foods that have either a high or low glycemic index. Before we can answer the question of today’s post – what is the Second-Meal-Effect? – we should first clarify what the glycemic index is.

What is the glycemic index? [1]

The glycemic index (GI) is a measure of how the consumption of a carbohydrate food affects blood sugar levels. If the glycemic index of a food is high, the consumption of this food will result in a faster and higher increase in blood sugar levels than consumption of a food with a low glycemic index.What is the Second-Meal-Effect?

food glycemic index
glucose 100 (=reference value)
cornflakes ~81
oat flakes (cooked in water) ~55


What is the Second-Meal-Effect? 

The second-meal effect “means that foods such as legumes with their very low glycemic index (GI), i.e. a low influence on blood sugar levels after consumption, also have a blood sugar regulating effect on subsequent meals.[2]

In a study [3], two groups of subjects were given different meals for dinner. One group had red lentils (with low GI), the other a meal of soy protein isolate and glucose powder (with high GI). As expected, after dinner blood sugar rose higher in the glucose powder group than in the lentil group. The results of the blood sugar levels in the next morning were really interesting. Both groups received the same breakfast: glucose powder stirred into milk. The increase in blood sugar, however, was quite different. Although both groups received the same high GI carbohydrate breakfast, the increase in blood sugar was much lower in the group who had eaten lentils the night before.

So we can see that the consumption of low GI carbohydrate foods – in this case lentils – has an effect on the meal that is eaten afterwards. Legumes thus have a blood sugar regulating effect – even for the subsequent meal.



[1] https://www.ernaehrungs-umschau.de/fileadmin/Ernaehrungs-Umschau/pdfs/pdf_2013/01_13/EU01_2013_M026_M038.2.pdf

[2] Rittenau, N. (2019): Vegan-Klischee ade! Wissenschaftliche Antworten auf kritische Fragen zu veganer Ernährung. Mainz: Ventil Verlag UG & Co. KG

[3] Wolever, T.M., Jenkins, D.J., Ocana, A.M., Rao, V.A., Cllier, G.R. (1988): Second-meal effect: low-glycemic-index foods eaten at dinner improve subsequent breakfast glycemic response. AM J Clin Nutr, 48(4), 1041-1047